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WHO/DIUOU DISTRIBUTION: GENERAL ORIGINAL: ENGLISH
Quality assurance workbook for radiographers & radiological technologists
by Peter J Lloyd MIR, OCR, ARMI~ Grad Dip FEd Lecturer (retired), School of Medical Radiation, University of South Australia
Diagnostic Imaging and Laboratory Technology Blood Safety and Clinical Technology Health Technology' and Pharmaceuticals WORLD HEALTH ORGANIZATION Geneva © World Health Organization, 2001
This document is not a formal publication of the World Health Organization (WHO), and all rights are reserved by the Organization. The document may, however, be freely reviewed, abstracted, reproduced and translated, in part or in whole, but not for sale for use in conjunction with commercial purposes.
The views expressed in documents by named authors are solely the responsibility of those authors.
Designed in New Zealand Typeset in Hong l 2001/13663- minimum graphics/Best Set/Interprint- 3000 Ill Contents Introductory remarks vii Acknowledgements viii Introduction 1 Purpose of this workbook 1 Who this workbook is aimed at 2 What this workbook aims to achieve 2 Summary of this workbook 2 How to use this workbook 2 Roles and responsibilities 3 Questionnaire-student's own department 5 Pretest 7 Teaching techniques 10 Overview of teaching methods in common use 10 Assessment 10 Teacher performance 12 Suggested method of teaching with this workbook 12 Conclusions 12 Health and safety 15 Machinery 15 Electrical 15 Fire 15 Hazardous chemicals 16 Radiation 16 Working with the patient 17 Disaster 17 Module 1. Reject film analysis 19 Setting up a reject film analysis program 19 Method 20 Analysis 20 Action 20 Tasks to be carried out by the student 24 Module 2. Accessory equipment 29 Collimator 29 Cassettes and intensifying screens 31 Grid 35 Lead rubber aprons and gloves 37 QUALITY ASSURANCE WORKBOOK IV Viewing box 38 Patient positioning aids 40 Patient measuring callipers 41 Tasks to be carried out by the student 44 Module 3. X-ray equipment 56 Choosing X-ray equipment 56 Acceptance of new X-ray equipment 57 Generator 57 X-ray tube, column, table and upright bucky 63 Tomography 65 Potter bucky 68 Portable and mobile X-ray units 70 Tasks to be carried out by the student 73 Module 4. Manual film processing 78 The darkroom 78 Film and chemical storage 81 Film processing 83 Tasks to be carried out by the student 95 Module 5. Automatic film processing 107 Choosing an automatic processor 107 Use of an automatic processor 108 Processor maintenance schedule 109 Sensitometry 112 Tasks to be carried out by the student 120 Module 6. Radiographic exposures 124 Exposure chart 124 The step system 126 Tasks to be carried out by the student 127 Appendix A. Mal Appendix B. Graphs, checl< sheets and record sheets 138 Reject film analysis 138 Remedial action record 141 Collimator check records 142 Record of all cassettes 143 Cassettes and screens 144 Lead rubber aprons and gloves 146 Viewing box 147 Fault report 148 Equipment record 149 Equipment maintenance and repair log 152 CONTENTS V X-ray unit 153 Constancy of radiation output at different mA settings 155 Darkroom inspection checklist 156 Specific gravity/temperature graph 157 . Automatic film processor 158 Processor maintenance checklist 160 Developer activity chart 161 Characteristic curve chart 162 Quality control processing chart 163 Exposure chart 164 Post test 169 Glossary 172 References 175 r VII Introductory remarks This document, which is developed by the International Society of Radiographers and Radiological Technologists (ISRRT) under the umbrella of the WHO Global Steering Group for Education and Training in Diagnostic Imaging, is the first in a series targeting technical aspects, including quality control of diagnostic imaging services. The document is primarily aiming at assisting radiographers and radiological technologists working in small and mid size hospitals where resources often are limited, to optimize and improve diagnostic imaging, and to ensure the best possible use of resources according to local needs. The document is distributed free of charge and can be obtained by contacting the following address: Team of Diagnostic Imaging and LaboratoryTechnology Fax: +41 22 7914836 Tel: +41 22 7913648 e-mail: [email protected] Harald Ostensen, MD Geneva, April 2001 VIII Acknowledgements Profound thanks are offered to everyone in Kenya who provided their wholehearted assistance, co-operation and enthusiasm in helping to produce this first workbook on quality assurance and pilot its implementation. Thanks in particular to: Kenya Ministry of Health University of Nairobi Nairobi Medical Training College Kenya Association of Radiologists Kenya Association of Radiographers Kenyatta Hospital, Nairobi and all other hospitals and government departments and individuals who participated in the initial research. Than I< you very much Asante sana Thanks also to all the people who assisted me in the production of this workbook: Roger Wind le, University of South Australia. R.ronda MilleG University of South Australia. Dean Hogben, Royal Adelaide Hospital. Michael FulleG Flinders Medical Centre. David Lesley, South Australian Radiation Protection Branch. Steven Johnson, South Australian Radiation Protection Branch. Graham Truman Rtd, Adelaide Womens and Childrens Hospital. Michael Canavan, Agfa-Gevaert Ltd. Graham BlucheG Hanimex Pty Ltd. Kenneth Gifkins, Kodak (Australasia) Pty Ltd. Introduction The World Health Organization (WHO) was founded Purpose of thjs workbook in 1948 and is a specialised agency of the United It is preferred to call this a workbook rather than a Nations. It promotes technical eo operation for health manual or textbook, because the intent is to, not only among nations, carries out programs to control and give technical information, but to set practical exer eradicate disease and strives to improve the quality of cises that students can work through, responding to human life. WHO has four main functions: specific questions. Above all, the students should feel • To give world wide guidance in the field of health. that they have actually carried out the tasks them • To set global standards for health. selves and will be more confident to teach others and • To co-operate with governments in strengthen ensure that these exercises continue to be carried out ing national health programs. in their respective areas. • To develop and transfer appropriate health tech The topic of this workbook is quality assurance, so nology, information and standards. all material is designed to assist in the maintenance of the highest quality of work that can be achieved, The WHO definition of health under the prevailing conditions. "Health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity." Quality assurance The overall management program, put in place The International Society of Radiographers and Ra to ensure that a comprehensive range of quality diological Technologists • return to their respective areas after completed • Provide a comprehensive knowledge, advice and training to teach other members of their staff to experience in quality control methods. carry out the routines that they have learned. • Provide the knowledge and skills to carry out basic care and maintenance of imaging equipment. In this way it is hoped that quality assurance will be • Raise standards. practised routinely and effectively. • Reduce imaging costs. • Improve job satisfaction. If so: • Improve health and safety issues. • Heads of departments will find that the stand ard of radiography will be maintained at the high Summary of this workbook est level. This workbook contains: • Work environments will be improved. • Tasks will become easier. • Background information. • Repeat films will be kept to a minimum. • A questionnaire seeking information about each • Staff job satisfaction will increase. students own department. • Patients will receive less radiation and less • A pre test of student's knowledge. inconvenience. • Advice on teaching methods. • There will be fewer equipment failures. • Health and safety issues. • Costs will be kept down. • Six modules giving technical information • A record and audit trail will exist as proof of high regarding effective routines and quality control standards. techniques. • Each module contains relevant tasks the student Achieve some of these and this worl dent's relevant knowledge before the course. This will Roles and responsibilities be compared to the results of a similar POST TEST The Head, Centre of Excellence completed by the student after completion of the course. These tests are for student information and The Head, Centre of Excellence will: course evaluation only and are not used in student • Hold the overall responsibility for the organisa assessment. tion and presentation of the training program The section on TEACHING TECHNIQUES first gives related to this workbook. a broad overview of teaching methods. This is followed • Be responsible for the selection of suitable tu by the recommended approach to teaching with this tors and ensure that they are fully trained and workbook. Both tutor and student should read this aware of their obligations. section. • Ensure that all necessary facilities and equipment The section on HEALTH AND SAFE1Y draws atten are available. tion to all the health and safety issues appropriate to • Arrange for workbooks to be in the hands of an X-ray department and how to make the work envi students at least two weeks before they start ronment a safe and healthy one. their course, for pre reading and discussion with The workbook is divided into modules. colleagues. • The student should work through one module at • Ensure that all training related to this workbook a time, studying the technical information and is carried out satisfactorily. testing methods. • Receive, review and sign all completed workbooks • At the end of each module, tasks have been set. and return them to the tutor for onward trans The student must carry out each task and an mission to the student. swer the questions asked. • Take any necessary action arising from completed - The tutor will assess the completed tasks and workbooks1 student performance or student answers, adding any appropriate comments. behaviour. - A Satisfactory/Unsatisfactory grade will be • Review the feedback questionnaire/ completed by given. the student1 and take any appropriate action. - All Unsatisfactory exercises must be repeated • Give feedback to the tutor. before beginning the next module. • Arrange for follow up checks to be carried out1 after a suitable period of time on each student All necessary equipment will be provided by the Centre 1 and what they have achieved in their own de of Excellence. The tutor will ensure that the student partment since completing the course. understands the technical information given in the • Evaluate follow up reports and take any neces workbook and will supervise and advise during the sary action. practical exercises. The APPENDICES contain information on making simple test tools, report forms, record sheets, test re The tutor, Centre of Excellence sult sheets and exposure charts, for use in the student's Each student will be allocated a tutor from the staff own department. of the Centre of Excellence. The tutor will: The GLOSSARY contains a list of terms, found in the text, with meanings. • Be responsible for students to whom they have The REFERENCES provide a source of further been allocated. reading. • Be readily available to students during their The POSTTEST must be answered on completion of training. the course. • Supervise and teach students during their The FEEDBACK QUESTIONNAIRE must then be training. completed and the workbook handed to the tutor for • Familiarise his/her self with the workbook, in final assessment and handing on to the Head, Centre particular the section on teaching techniques. of Excellence, for final approval. • Formulate a strategy for teaching this course and The workbook will then be handed back to the stu implement it. dent who will use it, on returning to their own depart e Read the questionnaire STUDENT'S OWN DE ment, to train other members of staff and to ensure PARTMEN~ completed by the student1 and de that a quality assurance program is established and vise an appropriate training program. carried out on a regular basis. • Ensure that all necessary equipment is available. QUALITY ASSURANCE WORKBOOK 4 • Ensure that the training program is carried out. STUDENT'S OWN DEPARTMEN~ before starting • Evaluate all tasks carried out by the student and the course. write appropriate comments and a grading at the • Carry out the PRETEST immediately before start end of each task sheet. ing the course. • Ensure that tasks graded "Unsatisfactory" are • Attend all scheduled teaching, practical and ad repeated before the student progresses to the ministrative sessions. next module. • Complete all modules, by first reading the tech • Mark pre and post course tests, completed by the nical information, carrying out the allotted tasks student, and make the student aware ofthe results. under the supervision of their tutor, and then • Write a final report on the student's performance. answering the questions. • Submit the student's completed workbook to the • Submit the workbook to the tutor; for evaluation, Head, Centre of Excellence for final approval. upon completion of each task. • Return the workbook to the student. • Repeat any task assessed as "Unsatisfactory" • Give adequate feedback to the student. before progressing to the next module. • Ensure that the student is fully aware of their • Carry out the POSTTEST immediately upon com responsibility to teach the course topics to fel pletion of the course. low staff members on returning to their own e Complete the FEEDBACK QUESTIONNAIRE. department. • At the end of the training period, and when all • Discuss with and advice students on how to carry tasks have been satisfactorily completed, hand out their own training programs. the workbook to their tutor for final evaluation • Advise the student that a follow up check will be and submission to the Head, Centre of Excellence made to assess the benefits of the course. for formal approval. The workbook will be returned. The student • On return to their own department, use the work book and newly gained knowledge and expertise The student will: to establish a quality assurance program and train • Complete all pre reading, discuss the material colleagues, under the direction of their Chief with colleagues and fill in the questionnaire, Radiographer. 5 Questionnaire Student's own department In order for this course to meet your needs, your tutor must know something about the department in which you worl<. Please answer the following questions in the spaces provided, before you commence the course. l. How many X-ray examination rooms are there?------ 2. Tell us what X-ray equipment you have. e.g. general purpose table with bucky etc. ROOM 1 ROOM 2 ROOM 3 3. Tell us what accessory equipment you have. e.g. Cassettes, positioning pads etc. 4. How many darkrooms are there?------ 5. State the type of film processor in each darkroom. e.g. manual/auto, type, make, model, processing cycle. DARKROOM 1 DARKROOM 2 QUALITY ASSURANCE WORKBOOK 6 DARKROOM 3 6. How many staff act as radiographers? Qualified radiographers ___ Others ___ 7. Is there an "out of hours service"? YES/NO 8. How many darkroom technicians are there?------ 9. Do you already run any form of Quality Assurance Program? YES/NO 10. If YES state here what you do 11. List any quality control test tools you have 12. If you have any quality assurance issues you particularly want covered, state them here 13. Give an indication of how busy your department is. Number of examinations per year/week/day _____ 14. Summarise the types of examinations carried out. e.g. extremities, chest, spine. Thank you 7 Pretest This test must be completed by the student before start 3. Reject film analysis means? ing the course. The intention is to test your knowledge a) To ask the radiographers how many films on the topics covered by this worl This is a multiple choice test. In each question you are b) Ratio of the height of the lead strips to their given three possible answers. length. Read each question carefully. c) Ratio of the height of the lead strips to the Indicate the answer that you feel is the most accu distance between them. rate by placing an "X" in front of the letter preceding it. Example: 5. A stationary grid is? A personal radiation monitor (TLD) should be worn a) A grid that is fitted in a bucky. a) Outside a lead rubber apron. b) A grid that can be carried around. X b) Under a lead rubber apron. c) A series of shelves for filing papers. c) There is no need to use one when wearing a lead rubber apron. Answer: b) 6. To test for poor film screen contact: All questions must be answered a) X-ray a lot of paper clips on the face of the cassette. l. What is meant by the term "quality assurance"? b) Open the cassette and look. a) The equipment is covered by an insurance c) Place a sheet of fine wire mesh inside policy. the cassette with the film and make an b) Everyone must produce perfect films. exposure. c) A system which attempts to maintain a high quality of work all round. 7. To check if the light field and the X-ray field of a collimator are correctly aligned: 2. What is meant by the term "quality control"? a) Look into the collimator mirror. a) A practical exercise which carries out qual b) Open and close the collimator shutters ity checks. rapidly. b) A staff member who supervises quality. c) Place metal markers on the face of a loaded cassette to indicate the light field and make c) An X-ray machine system that gives the cor an exposure. rect exposure. QUALITY ASSURANCE WORKBOOK 8 8. The coincidence of the X-ray and light fields of a 15. Stock rotation, related to film storage, means: collimator are said to be acceptable when: a) Turning the film boxes around. a) The X-ray field is 15 mm inside the light field b) First in first out. at lOOcm FFD. c) First in last out. b) The X- ray field is 3 mm outside the light field at lOO cm FFD. 16. A characteristic curve: c) The X- ray field is 8 mm inside the light field at lOO cm FFD. a) Determines the shape of an object. b) Represents the characteristics of the developer. 9. The wattage of a light bulb in a darkroom safelight facing down should be: c) Is a graphical representation of the relation- ship between the exposure received by the a) 15 watts. film and the density produced, following b) 50 watts. processing. c) lOO watts. 17. Safelights facing down should be installed: 10. Static electricity: a) No less than l30cm above the workbench. a) Produces an overall grey fog on processed b) No less than lOO cm above the workbench. film. c) At least 150 cm above the workbench. b) Produces black lightning like marks on proc- essed film. 18. Automatic processing developer temperatures c) Reduces the effect of the intensifying should be: screens. a) 20°C. b) 25°C. 11. A densitometer: c) 35 °C. a) Accurately assesses film density. b) Determines the efficiency of lead rubber. 19. In manual processing the film should be: c) Determines the light output of intensifying screens. a) Agitated every 30 seconds in the developer. b) Placed in the developer and not touched until the timer sounds. 12. A Sensitometer: c) Agitated by moving the film sideways. a) Is a motion detector. b) Is a radiation detector. 20. In manual processing, when transferring the film c) Is a device for making test strips used in from the rinse to the fixer, the film should be film processor monitoring. drained into: a) The rinse. 13. Fixing time in manual processing should be: b) The fixer. a) Two minutes. c) Doesn't matter. b) Twice the clearing time. c) Twenty minutes. 21. In addition to a visual safelight check you should: a) Hold an unexposed film against the safe light 14. X-ray film should be: for one minute. a) Stored at a temperature of 10 o to 20 °C. b) Expose sections of a film to safelight for pro- b) Stored lying flat. gressively longer times. c) Handled only in total darkness. c) Stand in the centre of the darkroom hold- ing a film for one minute. PRETEST 9 22. If the lid has accidentally been left off a box of 27. Replenishment rates in automatic processors are unexposed films in white light: checked by: a) Throw all the films away. a) Catching the amount pumped in a gradu b) Put the lid back on and do nothing until ated flask. someone tells you their films are fogged. b) Asking the manufacturer. c) Process three films and inspect. c) Measuring the drop in level of the replenish ment bottle/tank. 23. The First Aid treatment for a processing chemical splash in the eye is: 28. To check that a generator always gives the a) Blink continuously for 30 seconds. same output when using the same exposure factors: b) Wash thoroughly. a) Watch the mA meter during the exposure. c) Wipe the eye with a tissue. b) Expose three separate on the same film, using the same exposure factors. 24. The test to determine optimum development time cl Expose three different cassettes using the is: same exposure factors. a) Develop test strips for differing times and compare. 29. A spinning top test is used to: b) Develop an unexposed film and inspect. a) Check the accuracy of the timer. c) Develop test strips for the same length of time. bl Check the accuracy of the mA. cl Check the accuracy of the kV. 25. When shutting down an automatic processor: a) Clean crossovers and leave lid partially lifted. 30. To test for constancy of t·adiation output of an X ray unit: b) Switch off and leave it. a) Make several exposures using a different kV c) Turn water off only. each time. bl Make three exposures keeping the kV the 26. Developer temperature should be checked: same1 but vat·ying the mA. a) Only when film densities look different. cl Make three exposures keeping the kV and b) Once a week. mAs the same but varying the mA and c) Daily. time. 10 Teaching techniques How you teach a subject is very important. The most Demonstration highly sl Methods of presentation Self directed learning Lecture • The student is given the topic and the expected • Stand or sit in front of a class and verbally give outcome. the relevant information. • The student does their own research and prob • Suitable for large and small classes. lem solving. • Rather inflexible. • Exchange of information and group problem solv • Can be boring. ing is encouraged. • Audio visual aids can be used. • Usually followed up by a tutorial and a written • Printed notes can be given out in support of the confirmation of the student's knowledge. spoken word. Context based learning Tutorial • Problem solving, in groups. • More informal than the lecture. • Suitable for smaller classes. Presentation • Students are encouraged to present material and • The student researches the topic and gives a talk enter into group discussion. to other students. • The teacher acts more as a facilitator. • The teacher acts as facilitator and assessor. • Participants can sit around a table or in a circle. • Feedback is important. Assignment • The student researches a set topic and hands up Practical a written presentation to the teacher. • Students carry out a practical exercise under teacher supervision. Workbook • Verbal or written instructions may be made avail • A specialised book that poses questions and/or able to the student. sets practical tasks. • The practical should be relevant to recently ac • Answers are generally recorded in the book. quired information. TEACHING TECHNIQUES 11 Book review • In the case of a practical, ensure before hand • To encourage students to read certain books. that it will work. • The student is asked to present a written sum mary and comment on the book. Running a practical • Identify each piece of equipment. Posters • Explain the procedure. • Can be done in work groups. • Outline the aim. • May be used as teaching material at a later stage. • Demonstrate if necessary. • Could be displayed in department to convey • Identify likely problems. information. • Observe student carrying out the task. • Comment as necessary. Presentation technique • Be available to assist or answer questions. In any form of presentation by a teacher to a class, the Feedback to the student following points should be considered: Following any learning activity performed by the stu • Stand or sit where students can see you. dent, the teacher should give feedback to the student • Address them clearly. regarding their performance. • Use language they can understand. • Mark I grade achieved. • Present your facts logically. • Method. • Speak directly to the class. • Content. • Cast your eyes around the class as you speak. • Technique. • Use visual aids where necessary. • Performance. • May use flip charts. • Presentation. • In a tutorial or practical situation the teacher • Or whatever is appropriate. acts largely as a facilitator. Assessment Teaching aids • 35 mm slides. • Written examination. • Overhead projection COHPJ. - Multiple choice. • Video - Short answer. • White Board I chalk Board - Essay. • Butchers paper. - Numerical answer. • Models, - Problem solving. • Charts. - Open book. • Radiographs. - Fill in a missing word. • Pieces of relevant equipment. -Tick a box. • Printed notes. • Practical task (written question and answer). • Practical task (teacher observed-must have a Preparation pre-determined mark sheet). • Select the topic. • Assignment. • Research the topic. • Book review. • Assess the educational and technical level of the • Oral examination. students. • Decide on the breadth and depth of the material Grading student work to be covered. • Select the method of teaching to be used. • Written. • Select the teaching environment. • Verbal. • Prepare relevant teaching notes. • Practical. • Prepare relevant teaching aids. • The length of the session must match the time Forms of grading slot available. • Pass I Fail/Referred. • The amount of material to be presented must e ABCDEF match the length of the time slot. - Where A is the highest and F is the lowest. QUALITY ASSURANCE WORKBOOK 12 - A to E are graded passes. Sample evaluation puestionnaire of - E to F are graded fails. teacher performance • Distinction I Credit I Pass I Fail. • Were you able to hear? YES I NO • Marks out of 100. • Did the teacher start and finish • Marks out of 10. on time? YES I NO • Combined projectCs)/examCs) e.g. 50%/50% or • Was the material presented in a 25%/25%/50% logical way? YES I NO • Satisfactory/Unsatisfactory. • Was the material covered • No grading, the student simply attends classes adequately? YES I NO and completes all work set. • Was the presentation carried • Outcome based out satisfactorily? YES I NO • Can the student perform a task satisfactorily. • Was the attitude of the teacher • The student must be made aware of the grading satisfactory? YES I NO system. • Were the aim and objectives of • The student must be made aware of the results the course achieved? YES I NO of any assessment. • Further comment: • The teacher must allocate marks to the various parts of the material before marking Takes place. Teacher performance • Instead ofYES I NO the student could be asked • Start and finish on time. to choose from the following: • Plan content to fit the time frame. - Excellent. • Encourage questions. -Good. • Speak clearly. - Acceptable • Maintain a friendly discipline. - Needs improvement • Be well prepared: - Knowledge. - Notes. Conclusion - Teaching aids. • This section has set out to give you an overall • Mark all work fairly and accurately. insight into teaching. • Return all marked work as soon as possible. • Much of the material given will not directly apply • Give feedback. to your situation. • Regularly look around your audience. • You must choose what you feel is relevant to you • Humour is a useful tool if used properly. and carry out your teaching to suit your own needs • Don't be sexist, superio~ aggressive or con and those of the student. descending. Suggested method of teaching with How good are you at teaching? this workbook This book sets out to give the relevant information on Some ways of understanding how you perform as a the topics listed in the contents, regarding quality teacher: assurance, then sets simple tasks that students are • Evaluation questionnaire filled in by the student expected to carry out, responding to any questions at the end of a class or series of classes. asked. The teaching method used should therefore be • Ask someone to watch you teach and give you practically oriented. feedback. • Watch student reaction during a class. The tutor • Videotape a lecture, view it and then evaluate yourself. A tutor using this book must: • Become thoroughly familiar with the book. • Understand its contents and know how to per form all tasks set. TEACHING TECHNIQUES 13 • Know the answers to all questions asked. weeks before they start the course, for pre read • Understand and be able to run practical exer ing discussion with colleagues and completion of cises and carry out any other form of teaching the information about their department. considered appropriate. • Read the completed questionnaire, Student's own • Be able to select and use the most appropriate department1 and discuss with the student in method of teaching. order to determine their needs. • Make sure that all equipment needed is available. • Before starting the course the student must com- • Make sure the student understands what is re plete the Pretest. quired of them. • Outline the teaching format to the student. • Be available to advice while the student is carry- • Identify the topics to be covered. ing out the exercises. • Give a copy of the teaching program to the student. • Assess student's work fairly and accurately. • Cover one topic at a time. • Give useful feedback. • With each topic1 first give formal instructions • Be sympathetic to student needs. covering all the relevant information. • Answer any questions. Method • Allow the students to carry out the exercises. • The tutor should be available in an advisory capacity. It is suggested that a tutor use the following basic • Give the student time to complete the exercise teaching format: and any necessary written work. • Understand the student's needs. • Assess the practical component. • Devise an appropriate teaching program (lecture, • Assess the answers on the task sheet and make tutorial, practical etc.). written comment. • Ensure that you have all the equipment and teach • Grade the answers and practical performance ing aids that you require. Satisfactory/Unsatisfactory. • You should carry out a practical exercises your • Give feedback to the student. self first to ensure it works. • If the student's performance is unsatisfactory the task must be repeated. • Ensure that you have the correct answers/ results. • Continue with the next topic when a satisfactory • Issue the workbook to the student, at least two grade has been achieved. QUALITY ASSURANCE WORKBOOK 14 Notes 15 Health and safety Health and safety issues in any work environment are nections. Do not attempt to repair anything you do not very important. It is the responsibility of all Heads of understand. Department to ensure that injury or sickness, due to When carrying out any simple maintenance, repair, working conditions, is kept to a minimum. Injury or or cleaning of electrical equipment: sickness may increase absenteeism of staff members • Switch off and disconnect before starting. and reduce efficiency. Staff must not put patients, col • Do not tamper with anything you do not fully leagues or self at risk. understand. X- ray departments should be prepared for emergen • Unless you are qualified, restrict your actions to cies such as fire, major disaster or any life threatening replacing light bulbs, simple electrical parts, tight situation. Radiography involves working with: ening connections, replacing fuses and inspect • Machinery. ing cables. • Electricity. • Ensure that all parts are correctly and safely in • Hazardous chemicals. stalled or adjusted. • Radiation. • Ensure that all protective panels are replaced. • Patients. • Never use excessive amounts of water when clean ing electrical equipment. Fire and major disaster plans should be in place. • Report all faults to your immediate senior or Cardiac arrest training should be given. through the recognised channel. The first thing to consider is making the work envi • Ensure that other members of staff are aware of ronment as safe as possible, by minimising the risk of any problem. problems arising.To achieve this, ensure that: • Regular maintenance inspections are carried out. Fire • Safety procedures are followed. • Adequate staff instruction is given. Adequate fire fighting equipment, instructions, • Safety equipment is readily available. and evacuation procedures must be in place at all times. Machinery Equipment Regularly inspect all machinery. Do not attempt to re • Fire extinguishers. pair anything you do not understand. Call an X-ray en - Suitable for electrical fires, near electrical gineer if you are unable to fix the problem. equipment and switchboards. Take care with all moving parts, to minimise the - General purpose in all other areas. risk of: • Smoke detectors in all rooms. • Trapping fingers. • Hoses in central areas. • Loose parts falling off onto staff or patient. • Fire alarms easily accessible. • Equipment moving unexpectedly and striking • Regular maintenance of alarms and equipment. staff or patient. • Illuminated EXIT signs in all public area. • Staff or patient striking head on overhead equipment. • Emergency exit doors not locked or blocked. Fire fighting instructions Electricity • Readily available. Consult a qualified electrician or X- ray engineer. Regu • Staff training. larly inspect all electrical equipment, cables and con- • Annual refresher courses. QUALITY ASSURANCE WORKBOOK 16 Evacuation procedure • Select a suitable site where the chemicals can • Instructions readily available. be buried and are not likely to get into the local • Clearly defined evacuation routes. water supply or in any way affect humans, ani • Recognised assembly points. mals or crops. • Responsibilities clearly defined. • Further refinements of the "bury method" is to • Staff training. use a sand trap first, then bury the residual sand or use an evaporative trench lined with sand and Hazardous chemicals (laws and bury the sand when the water has evaporated. regulations to be followed) • Local soil, terrain and weather conditions should be considered. Developer and fixer are hazardous chemicals and should be handled with care. Display manufacturer's instruc First aid treatment tions for mixing, care and first aid treatment, in a promi • Follow manufacture's recommendations. nent place in the area in which the chemicals are to used. • Skin contact. - Wash thoroughly in water immediately. The risks involved are: • Eye contact. • Inhaling fumes or powders. - Wash eye thoroughly, immediately. • Swallowing. - Darkrooms should be equipped with emer- • Contact with the skin or eyes. gency eye wash kits. • Inhaled When mixing solutions: - Move out into fresh air immediately. • Work in a well-ventilated room. - Seek medical advice. • Avoid skin or eye contact with chemicals. • Swallowed • Wear a mask, goggles, rubber gloves and a plas- - Wash mouth and lips in clean water. tic apron. - Seek medical advice immediately. • Avoid splashes. • Wash all equipment used after mixing. Radiation • Clean up any spills or splashes. Follow national laws and regulations. When processing films: • Use an ongoing personal monitoring system. • Avoid skin or eye contact with chemicals. • Do not produce x-radiation unnecessarily. • Ensure that the darkroom is adequately ven- • Requests for X-ray examinations should be justi tilated. fied. • Minimise splashes. • Avoid the use of X-ray examinations on pregnant • Clean up any splashes as soon as possible. women wherever possible, especially in the first • Replace any tank lids when finished. trimester. • l exposures are made, warning when X-rays are • Use appropriate moving/handling aids when nec being used. e.g. screening rooms. essary and when available. • Make sure that all unnecessary personnel are • Encourage patients to move themselves where clear of the radiation area when exposing. possible. • Make sure that X-ray equipment is working prop erly and is safe, by carrying out regular quality Cross infection: control checks. • Be aware of any indications that the patient may • X- ray equipment should be switched off when not be infectious. in use and any safety lock keys removed. • Follow infection control procedures. • Use correct filtration of the X-ray beam. • Have gowns, gloves and masks readily avail • Special care must be taken when using mobile/ able and ensure that they are worn when portable X-ray units, in ward or operating theatre necessary. situations. • Disinfect all equipment used, immediately after • Apply the ALARA or ALARP Principle when ex use, not forgetting cassettes. posing anyone to radiation. • Where possible wrap cassette in towel or cloth before using, with an infectious patient. • Wash hands before and after each contact. ALARA principle When exposing anyone to ionizing radiation the Disaster dose should be kept A disaster is any major catastrophic event, earth As Low As Reasonably Achievable quake, major accident involving many people, civil dis turbance or war. A hospital must have an established An extension of this principle is the disaster plan that will allow it to cope with this type of ALARP principle event. An X-ray department must have its own emer When exposing anyone to ionizing radiation the gency plan that will fit in with the overall hospital dose should be kept plan. As Low As Reasonably Practicable Designing a plan: The inference here is that there may be other • Become familiar with the hospital plan. important factors which may limit the dose • Design an X-ray department plan that is com reduction. patible with that of the hospital. • Determine: - Individual responsibilities. Working with the patient - Staff call-out procedure. Moving and handling: - Organisation. • Use recognised moving/handling techniques to - Amount of stock to hold. reduce the risk of back injury. QUALITY ASSURANCE WORKBOOK 18 Notes 19 MODULE I Reject film analysis Aim Benefits • Able to identify the main errors and put meas To provide the knowledge necessary to set up a system ures in place to reduce them. which will give a detailed analysis of the rejected films • Save money by reducing wastage. and the reason for the rejections, in order to put in • Reduce radiation dose to the patient by mini place remedial action. mising the number of repeat films. • Save time and effort by reducing the number of Objectives repeat films. To provide all relevant information and give the oppor • Provide ongoing data for comparison. tunity to gain practical experience in: • Provide possible source of statistics to support • Designing a reject film analysis program. claims for more funding to replace, modify or Ill Setting up and running a reject film analysis repair faulty equipment. program. Ill Analysing the results of that program. Potential problems Ill Setting up remedial action based on those • Staff members do not co operate fully. results. • Radiologist and clinicians tend to retain substand Ill Instigating a follow up program to assess the ard films on the grounds that they provide some effectiveness of the remedial action taken. information. • Reject film records not always kept up to date. In every department a number of films are discarded for one reason or another. Incorrect exposure, poor positioning and processing are some of the common Frequency causes. • Monthly. Knowing exactly what the major reasons are is a big step towards correcting the faults and therefore Setting up a reject film analysis reducing the number of unacceptable radiographs. It program is not satisfactory to make judgements on impressions alone. A reject analysis can be an important part of • Design the program. your ongoing quality assurance program. • Determine the period over which the program will From a radiographers point of view a reject analysis run. may be seen as a threat. It is important to fully explain • Nominate a starting and finishing date and time. to all concerned: • Inform staff (the full eo operation of the staff is important): • Why the analysis is being carried out. - Why the program is necessary. • How it will be carried out. - How it will operate. • When it will be carried out. - When it will take place. • The benefit. - Who is responsible for the program. Sensitometry and radiation consistency tests should • Decide what data you need. be run in parallel with a reject film analysis as process • Design data recording sheets. ing or radiation output irregularities may be causing • Place reject film boxes in appropriate areas. some of the problems. QUALITY ASSURANCE WORKBOOK 20 It is usual to collect reject films from individual X-ray • Overall number of reject films. rooms. It may be necessary to relate the collections to • Number of reject films by size. the individual radiographer as well. • Number of reject films by faults. .e Number of reject films by rooms Cor • Immediately before program starts: radiographers). - Count all films in store by sizes. • Overall cost of rejected films. - Add to this count all unexposed films in cas- • Identification of common faults. settes, film hoppers and partially empty boxes. • Reject films as a percentage of films used. - Record this information. - Dispose of all current reject films. Study the data. Compare current data with that of previous programs. Method A reject rate of 10% or more should be considered unacceptable. A reject rate of 5% to 10% justifies con • Collect all reject films daily. tinued monitoring. • Record numbers of reject films on data sheets daily (see Fig 1-1, Fig 1-2, Fig 1-3 and Appendix Action B, pages 138-140). • Immediately the program has finished re-count • Rank the faults in order of frequency. the films in the store, cassettes and half empty • Identify the most common faults. boxes. • Set up remedial programs to correct errors (see • Original film count, minus end film count, equals Appendix B, page 141). number of films used. • Inform staff of findings and planned remedial • Analyse the data. action. • Start remedial action program. Analysis • Nominate dates for another analysis if felt necessary. The following information can be obtained from an • File data for future reference. analysis of the data: MODULE I, REJECT FILM ANALYSIS 21 Reject film analysis Daily totals by location Date: Cause Location Room l Room 2 Room 3 Room 4 Total Projection Movement Under exposed Over exposed Static Fog (darkroom) Fog (cassette) Equipment Processing Other Total Total films rejected today: ______Fig 1-1. Reject film analysis, daily record sheet by location QUALITY ASSURANCE WORKBOOK 22 Reject film analysis Daily totals by film size Date: Film size Ccm) No. of films Film used Csq m) 1 35 X 43 2 35 X 35 3 30 X 40 4 24 X 30 5 18 X 24 6 18 X 43 7 DENT I OCC 8 Other Total Total number of films: ______Total square meters of film: ______Total cost of rejected film today: ______Fig 1-2. Reject film analysis, daily record sheet by film sizes MODULE I. REJECT FILM ANALYSIS 23 Reject film analysis Daily totals Period: From: ____ To: ____ Cause Dates Total I I I j I 'I Projection I I I Movement Under Exp. Over Exp. Static Fog (darkroom) Fog (cassette) Equipment Processing Other I i I i I i Totals Total films rejected: ______Total films used: ______Rejected films as a percentage of films used: ______Cost of films rejected this period: ______Fig 1-3. Reject film analysis daily totals sheet QUALITY ASSURANCE WORKBOOK 24 Notes MODULE I. REJECT FILM ANALYSIS 25 TASK I Reject film analysis You have become aware that the number of rejected films is increasing, but you have no idea what the main faults are and what is causing them. You decide to investigate the situation. Take the first step and practise analysing films for faults. a) Select any three rejected films. b) Study these films. c) List all faults seen, in order of importance, that you believe led to the rejection of the film. FILM 1 FILM 2 FILM 3 I I I l. How do you think these faults were caused? Film 1 Film 2 QUALITY ASSURANCE WORKBOOK 26 Film 3 2. What would you do to eliminate these errors? Film 1 Film 2 Film 3 Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor MODULE I. REJECT FILM ANALYSIS 27 TASK2 Reject film analysis Your next step is to carry out a small pilot reject film analysis. a) Carry out a one room reject film analysis over a period of 5 to 6 days (see notes). b) Analyse your results. c) Answer the following questions in the spaces provided. 1. Total number of reject films:------ 2. Reject films as a percentage of total films used:------ 3. Total area in square metres, of rejected film:------ 4. Cost of rejected film?------ 5. List the three main causes of film rejection: 6. Explain what measures you would put in place to eliminate these causes: QUALITY ASSURANCE WORKBOOK 28 Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor 29 MODULE 2 Accessory equipment Aim Grid Grid types ratio and line. To provide the knowledge and practical skills neces 1 ·•· _ Care and cleaning. sary to establish and carry out a quality control pro Visual inspection. gram for accessory equipment. Grid line damage. Objectives Lead rubber apron, gloves and sheets On completion of this module you will be able to un Visual inspection. Cracking. derstand and carry out quality control procedures1 evaluation and recommend action for: X-t·ay testing. • Care and cleaning. Collimator Storage. Ill Visual inspection. Ill Accuracy of scales. Viewing box Ill Change a light bulb. Electrical inspection. Ill Light beam/X-ray beam alignment and Efficiency/consistency. centring. Location. Ill Lead shutter efficiency. Cleaning. Cassette/intensifying screens Patient positioning aids Ill Visual inspection. Visual inspection. Ill Light tightness of cassette. Radiolucency. Ill Film/Screen contact. Condition. Ill Intensifying screen light colour emission. Cleaning. Ill Care and cleaning. Patient measuring callipers Accuracy. Damage. Collimator Visual inspection (see Appendix 81 page 142) • Rotation. The collimator/sometimes referred to as the light beam • Stability. diaphragm (LBD) provides the radiographer with an 1 • Knobs fot· shutter control. easy to use/ accurate/ method of controlling the size of • Accuracy of shutter setting scales (if present). the X-ray field and placing it over the area of interest r • Shutter chain drive. thus reducing the radiation dose to the patient and • Shutters. improving the quality of the image. • Housing. The collimator receives much use and is vulnerable • Window. to knocks/ often resulting in inaccuracy of the light • Light timer. beam/X-ray beam coincidence1 blown light bulbs1 elec • Timer switch. trical and mechanical problems. • Cables. QUALITY ASSURANCE WORKBOOK 30 • Plugs. Method • Light bulb. • Switch off the power. • Light/X-ray beam alignment. • Remove relevant collimator housing. • Check that spare is the correct type. Accuracy of scales test • Before removing the old bulb, check to see if the Not everyone uses the aperture size scales on the col replacement bulb must befitted a specific way round. limator to set the aperture size, it being more common • Replace faulty bulb with the new one. practice to use visual assessment of the light field size. • If the bulb is of the quartz type, ensure that it is However if staff do practice this method, it is advisable not handled with bare fingers, as body oil on the to make sure that the scales are accurate. bulb will shorten its life. Inaccuracy of scales may lead to inaccurate col • Replace housing and tighten screws. limation. • Test. • Ensure that the spare bulb is replaced as soon as Frequency of test possible. • 6 monthly. Light beam/X-ray beam alignment test Equipment required The purpose of the light in a collimator is to allow more • Collimator to be tested. accurate collimation of the X-ray beam. The light must, • lOO cm rule. therefore, coincide with the X- ray beam.The light beam relies on the accurate positioning of the light bulb and Method angled mirror inside the collimator. • Set lOO cm focus to tabletop distance. Should either the mirror or light bulb be dislodged, e Using the lOOcm FFD CSID) scale on the colli then errors in collimation could occur, resulting in mator, set various aperture sizes with the light areas of interest being excluded from the field, or too on and measure the resultant light areas at table large an area being irradiated. top level. • Compare with settings on the collimator. Frequency of test • 6 monthly. Evaluation • As necessary. • Light area measured should be the same as the setting on collimator. Equipment required • One 24 x 30 cm loaded cassette. Action • Alignment test tool. Commercially made test tools • If settings are not accurate and the solution is are available, but a simple alternative is to use not a simple one, call an X-ray engineer. eight coins or four paper clips (see Fig 2-l, Fig • File a report. 2-2). • Lead marker or ninth coin. Changing a light bulb A light bulb can fail at anytime without warning. It is Method important then, to have the correct spare bulb readily • Make sure that the table is level and the central available. ray at 90 o to the tabletop. Staff should be capable of replacing a faulty bulb. • Place a loaded cassette on the tabletop face up. DO NOT ATIEMPTTHIS UNLESS YOU HAVE HAD AD e Set a FFD CSID) of lOO cm. EQUATE INSTRUCTION. If unsure, call an electrician. • Switch on the collimator light. • Centre to the middle of the cassette. Frequency • Collimate to within the edge of the cassette, leav • As necessary. ing a 3cm border all round, that is outside the light field. Equipment required • Place the coins in pairs, so that, where the coins • Suitable light bulb. touch, coincides with the edge of the light area. • Cloth or tissue. • All four borders of the light must be marked in • Screwdriver. this way. MODULE 1. ACCESSORY EQUIPMENT 31 • At lOO cm FFD (SID) the irradiated area must not be more than 10 mm smaller than the area cov ered by the light. This represents a l% tolerance. Action • If the alignment is unacceptable it must be adjusted. • Call an X-ray engineer. Note: Cones and diaphragms can also be checked us ing a similar method. Shutter efficiency test Fig 2-1. Light/X-ray beam alignment test Closing the shutters in the collimator fully should using eight coins prevent any radiation from reaching the film. Useful for testing radiation safety when discharging cap acitor discharge mobiles or making tube warm up exposures. Frequency of test • 6 monthly. Equipment required • One loaded 24 x 30 cm cassette. Method • Place the cassette on the tabletop face up. e Set a FFD (SID) of lOO cm. Fig 2-2. Light/X-ray beam alignment test tool. • Set an exposut·e of approximately 80 kV and Radiation Measurements Inc. 40mAs. • Open one set of shutters fully, leaving the other closed. • Place the lead marker within one corner of the • Make an exposure. light field so that the film can be related to • Fully close the open shutters and open fully the the light/X-ray field and hence the collimator closed ones. shutters. • Make another exposure. • Make an exposure sufficient to blacken the film. • Process the film. • Process the film. Evaluation Alternative method instead of using coins • Study the film. If the shutters are efficient the • Use four paper clips, each bent to form right an film will not have been affected by radiation. gles. • Place paper clips at corners of light field. Action Note: Collimators are known to become less accurate • If the shutters are allowing radiation to pass, call as the field size is increased. To check this make two an X-t·ay engineer. flash exposures on the same film, following the method described above, using different field sizes, remember Cassettes and intensifying screens ing to re position the markers for the second exposure. Cassettes are the light tight containers that hold the Evaluation X-ray film between the intensifying screens. They are • For perfect alignment, the light field (where the avaiiable in a range of sizes to suit every need. coins touch) should coincide with the X- ray field. Intensifying screens fluoresce when struck by ra • The irradiated area must not be greater than the diation, the light emitted significantly contributing to area covered by the light. the blackening effect on the film. QUALITY ASSURANCE WORKBOOK 32 Cassettes are easily damaged and likely to wea~ result Equipment required ing in possible light leakage and poorfilm screen contact. • Cassettes to be tested. Intensifying screens deteriorate over time and are easily damaged. Foreign material on their surface or Method damage will create marks on films. • Load cassette with new film. All cassettes should be clearly numbered on the • Place cassette under bright light for approxi outside. A corresponding number being placed inside, mately 15 to 30 minutes. on the edge of one of the screens, using an indelible • Turn cassette and repeat. marker, where it will not affect the image, but is visible • Process film. on the radiograph. All cassettes should be marked on the outside, iden Evaluation tifying the type of intensifying screens fitted. • Black fogging around the edge of the film is an If different film/screen combinations are used in the indication of light leakage. department, screen speed should be clearly indicated on the outside of the cassette. It is usual for manufac Action turers to supply appropriate labels with their screens. • Repair or replace cassette. Both cassettes and screens should be inspected and • File report. cleaned regularly. Records must be kept of all inspec Note: Similar fogging can be caused by a lid being left tions, maintenance and replacements. off a box of film or the film hopper left open, allowing white light exposure of the upper edge of the films. Cassettes (see Appendix B, pages 143, 144 & 145) Cassette inspection Intensifying screens Frequency of inspection Most cassettes are fitted with a pair of intensifying • Yearly. screens and should be used with double emulsion film. • As necessary. Blue light emitting screens should be used with blue light sensitive film. Equipment required Green light emitting screens should be used with • Cassettes to be inspected. green light sensitive film. Any damage, deterioration or foreign matter will be Method seen in resultant images. • Inspect: • Hinges. Intensifying screen inspection • Catches. Frequency of inspection • Casing. • Monthly. • Cleanliness. Equipment required Evaluation • Screens to be inspected. • Faulty parts, distortion and inadequate cleanli ness must be attended to. Method • Inspect in bright light conditions. Action • Screens firmly fitted. • Repair faults or replace cassette. • Correct screens fitted (see label on back of • Carry out film/screen contact test. cassette). • Clean with damp cloth and wipe dry. • Correct number on edge of screen (see number • l Light leakage test Evaluation Frequency of test • Abrasions. • Yearly. • Foreign material on surface of screen. • As necessary. • Discolouration Can indicator of deterioration). MODULE 2. ACCESSORY EQUIPMENT 33 • Fitted correctly. Equipment required • Correct screens. • Cassette to be tested. • Test tool (box of paper clips or sheet of perfo Action rated zinc or fine wire mesh, large enough to cover • Loose screens should be re-fitted with double a 35 x 43 cm film, with a square hole, about 10 cm sided tape. from one edge, approximately 2 to 2 cm square). • Surface damage or deterioration, which is unac (see Fig 2-3 and Appendix A, page 134). ceptable-rep/ace screens. • Lead marker if cassettes do not have a lead • Clean if necessary. blanked area for patient details. • File report. Intensifying screen cleaning Frequency of cleaning • Monthly. Equipment required • Soft brush. • Puffer. • Lint-free cloth, such as gauze. • Screen cleaner (available from manufacturer) or mild soap (not detergent). Method • Clean in bright light conditions. • Remove all loose dirt with a soft brush or puffer. • Apply screen cleaner sparingly, with a lint free cloth, such as a gauze swab. • Use circular motion over whole surface. Fig 2-3. Film/screen contact test, using paper • Finish off with Joug strokes from top to bottom. clips as a test tool • Do not pour cleaner directly on to the screen. • Wipe with dry lint free cloth. Method • Stand cassette open for 30 minutes to dry. • Load the cassette to be tested and place it face • Inspect. ~1p on the tabletop. • Cover the whole of the cassette with the test tool Evaluation (if using paper clips, distribute evenly). • Have all dirt particles been removed? e Set a FFD (SID) of 150 cm (the longer FFD CSID) • Are there any smears? reduces geometric unsharpness). • Collimate to cover whole of cassette. Action • If appropriate, place lead marker in the corner • If dirt particles or smears remain, re clean. of the cassette face, in order to relate resultant • If, after repeated cleaning, dirt particles remain, radiograph to cassette. decide if they are likely to be a problem. • Make an exposure using about 50 kV and 6 mAs • If they are considered to be a problem, replace (film density of 1 to 2). the screens. • Process the film. Film/screen contact test Evaluation If an area of localised blurring is detected on a radio • If a densitometer is available the film density can graph, poor film/screen contact should be suspected. be measured at the image created by the hole in the test tool. Frequency of test • Inspect the image, looking for areas that look • Yearly. blurred. • As necessary. • A noticeable area of unsharpness could be caused by: QUALITY ASSURANCE WORKBOOK 34 - A damaged cassette. change the type of film you use so that they are - Screen packing, deterioration. compatible. - An air pocket. • If the light intensity comparison between pairs • When using a close mesh wire test tool the poor of screens is noticeably different, check the la film/screen contact areas may also have a higher belling of your cassettes for screen type and/or density. carry out the intensifying screen consistency test. Action • Re label the outside of the cassette if necessary. • Repair or replace cassette. • Replace packing. Intensifying screens consistency test • Re-test. The efficiency of screens tends to deteriorate over time. • File a report. If you have screens of the same type, but of differing ages, you cannot assume that they will all give the same Film/screen compatibility-colour of light result. It is therefore necessary to check the efficiency emission test of all screens periodically in order to achieve consist Different types of intensifying screens may emit differ ent results. ent light colours and/or intensities. The colour of light emitted by screens must be the same as the colour Frequency of test sensitivity of the film used with them. Check with your • Yearly. film and screen suppliers if in doubt. • As required. If there is any doubt about the colour compatibility of the light emitted by the screens, the following sim METHOD I ple test can be used. Equipment required • Step wedge (see Appendix A, page 133). Frequency of test • Loaded cassettes with screens to be tested (all • As necessary. cassettes should be loaded from the same box of film). Equipment required • Densitometer, if available. • Screens to be tested. Method Method • Cut a sheet of film into strips large enough to • Open the cassette. easily cover the step wedge. • Remove the film. • Load each cassette to be tested with one strip of • Place the open cassette, screen facing up, on the film, placed centrally. tabletop. • Place the first cassette on the tabletop, face up. • Set a FFD (SID) of lOO cm and collimate to cover • Place the step wedge in the centre of the cas the open cassette. sette so that it is directly over the film strip • Reduce room lighting to a minimum. inside. • Make an exposure using a relatively high kV • Set a lOO cm FFD (SID) and collimate to cover and long time, e.g. 80 kV and maximum time the step wedge. possible. • Set an exposure that will give a full range of den • Observe the screens during the exposure. Remem sities on the step wedge image (you may need to ber to follow normal radiation safety rules. do test exposures first). • Expose. Evaluation • Process the film. • Note the colour of light given off by the screens. • Repeat the procedure for all the other cassettes • Note the intensity of the light given off by the being tested, using exactly the same conditions. screens. • Label the film strips with date and cassette number. Action • For accuracy of this test, the X-ray output and • If the colour sensitivity of the film is not the same processing must be consistent throughout. as the screen light emission colour, you should MODULE 2. ACCESSORY EQUIPMENT 35 Evaluation • If this is impractical, work out the exposure dif • Place the test strips side by side on the same ferences to achieve similar results and label each viewing box. cassette accordingly. • Compare the densities (a densitometer will give When equipping a department with all new screens it a more accurate result). is advisable to carry out this test as a basis for future • Assess the density differences between the strips. comparison. • If the film strip images, using screens of similar types, are seen to vary noticeably, this is unac ceptable (densitometer readings of similar steps Grid should be within 10% of each other). The purpose of the grid is to reduce the amount of • Assess the density differences between the strips. scattered radiation reaching the film. This greatly im proves the quality of the image. Although the quality METHOD 2 of the image is improved, it does mean a significant Equipment required increase in exposure, and therefore dose to the • Phantom (water filled flagon, or other suitable, patient. even density material, of at least 30 x 30 cm area). A grid looks like a simple thin sheet of soft metal, (see Appendix A, page 133). but it is in fact a precision made piece of equipment • Loaded cassettes with screens to be tested (all and easily damaged. It is made up of a large number cassettes must be loaded from the same box of of fine lead strips interspaced between radiolucent film). strips. If the lead strips become distorted the grid will • Densitometer, if available. be less efficient and irregular densities will be created on the film. Method If the grid is used wrongly, abnormal densities (grid • Place four of the cassettes together, face up on cut off) will be produced. e.g. a focussed grid used up the tabletop, so that one corner of each cassette side down will create a reduction in density the further meets the others and the appropriate edges are the area is from the centre line. in contact. e Set a FFD (SID) of 100cm. Grid types • Centre to the touching corners of the cassettes. • Place the phantom to partially cover all four Stationary cassettes. • A loose grid which can be placed directly over • Collimate to within the phantom so that a por the face of the cassette. tion of each cassette will be irradiated. • The grid and cassette size must be the same. • Set an exposure that will produce a measurable • The grid ratio is usually 6: 1 or 8: 1. density on the film and expose. • Cassettes are available with a built in, or added, • All screens to be assessed should be tested in grid. this way, keeping one of the cassettes unchanged throughout. Remember to reload the control cas Moving sette each time. • A grid used in a potter bucky system, which moves • Identify all films using the cassette numbers. from side to side during the X-ray exposure, in • Process the films as soon as possible using the order to defuse out the images of the lead same processor. strips. • The grid ratio is usually 10: 1 or 12: 1. Evaluation • The grid ratio should be 16: 1 if used for high kV • Compare the densities produced on each radio work. graph (a densitometer will give a more accurate result). Parallel line • Densitometer readings should be within 10% of • Lead strips run parallel to one another in one each other. direction only. • There are two types of parallel line grid, focused Action and non-focused. • If significant differences are seen you may wish • Moving and stationary grids are all of parallel to re screen all cassettes tested. construction. QUALITY ASSURANCE WORKBOOK 36 Focused • A parallel line grid. • Differs from the non focused grid only in that the lead strips progressively incline more inward, the further they are from the centre line, so that they are focused to a pre-determined point above the grid. Fig 2-4. Diagram of a parallel line grid. Plan view / : . \. / i Cross-hatch j • Two sets of lead strips superimposed and run .! ' ning at 90 o to one another. / \ ··. • Generally a stationary grid, used only for rela •. tively high kV work and when no tube angulation is necessary. • This design is used only in stationary grids. Cal (b) Fig 2-7. Diagram of a parallel line focused grid, (a) Plan view, (b) End view Structure • Thin lead strips interspaced between equally thin strips of radiolucent material. • Covered top and bottom with thin aluminium Fig 2-5. Diagram of a cross-hatch grid. Plan sheet. view Non-Focused Radiolucent strips • A parallel line grid. (distance between lead strips) • Relationship of lead strips uniform to one an other throughout. 1111111111111 Lead strips (b) Fig 2-8. Diagram of grid construction, end view Specifications The detail of the grid structure should be marked on Cal the surface of the grid either by a label or imprinted Fig 2-6. Diagram of a parallel line, non into the metal. focused grid, (a) Plan view, (b) End view MODULE l. ACCESSORY EQUIPMENT 37 Grid ratio The ratio of the height of the lead strips Equipment required to the distance between them. • Grid to be tested. Grid line The number of lead strips in a grid. • One loaded cassette, same size as grid. Stated as the number of lead strips to • One lead marker. the centimetre (or to the inch). Focal range Grids are designed to be used within METHOD given focus film distances {source image Visual inspection: distances} dependent on the way the • Dents, bends, creases, damaged corners. lead strips have been focused. • Specifications marked. Grid line The direction in which the grid lines • Cleanliness. direction travel is indicated by a line down the cen tre of the grid on the tube side. Cross X-ray: hatch grids have a second line running • Place cassette on table top, face up. at 90° to the first. • Place grid to cover cassette, tube side up. Tube side The tube side is shown by a label stating • Set a FFD (SIDJ in the middle of the known focal TUBE SIDE, or an X-ray tube symboi.The range of the test grid or lOO cm. lead strips direction line also indicates • Centre to middle of grid. the tube side. • Central ray at 90 o to cassette/grid. • Collimate to cover cassette/grid. Care of the grid • Set an exposure of 50 kV 10 mAs (you may need to experiment prior to the test). • Stationary grids should have an added, rigid, PVC • Expose. protective cover. • Process film. • When a protective cover is added the grid speci fications must be recorded on the new cover for Evaluation future reference. • Is grid line pattern regular? • Do not bend, drop or dent the grid. • Is overall density even? • Clean regularly. • Store in a safe place. Action • If the grid line pattern or density is unacceptable Use of a stationary grid repeat the test using FFDs (SIDsl of 10 cm • Use a grid that is the same size as the either side of that used in the first test. cassette. • If the images are still unacceptable, replace the • Place the grid against face of cassette with noth grid. ing between it and the cassette face. • File a report. • Check that the tube side of the grid is toward Note: This test can also be used to check the focal the tube. range. • Use strips of adhesive tape to hold the grid in place. Lead rubber aprons and gloves • Use the recommended focus film distance (source image distance) for that grid. Lead readily absorbs t·adiation and is used in many • The X-ray beam must not be angled across grid forms and thicknesses in the field of radiation lines. protection. e.g. lead sheet, lead rubber, lead acrylic. When using a grid cassette, only the last two points Lead rubber has the advantage of being flexible and are relevant. can therefore be made into items which can be worn e.g. aprons and gloves. Lead rubber tends to deterio Grid line damage test rate over a period of time, with regular use and mis Frequency of test handling. Regular care, cleaning and testing are • 6 monthly. important (see Appendix B, page 146). • As necessary. QUALITY ASSURANCE WORKBOOK 38 Other lead rubber items • Relocate storage location if unsuitable. • Gonad shields. • Re-design hangers if unsuitable. • Thyroid shields. • Re-educate staff if they are not hanging/storing • Small sheets of differing sizes. items correctly. • Shielding on screening units. • Replace if necessary. • File a report. Care • Weekly cleaning or as necessary. Clean with soap Test to detect cracking of aprons or gloves and water. Frequency of test • Never fold any item of lead rubber. • Yearly. • Aprons should be hung up using strong, specially • As necessary. designed hangers. • Store gloves flat or upright on a custom made Equipment required holder. • Screening X-ray unit Cif a screening unit is not • Do not store near a heat source. available, use a general purpose unit and 35 cm x The lead equivalent (effectiveness) of all forms of 43 cm cassettes). lead rubber should be known. Aprons for instance are • Items to be tested. designed only to protect against scatter. They have a lead equivalent of between 0.25 mm and 0.5 mm. Method Lead sheet may have a lead equivalent of 2.0 mm or • Spread article to be tested on the tabletop. 3.0 mm. • Use screening system to examine whole article. • Use different kV s. Visual inspection test • If a general purpose X- ray unit is to be used, place cassettes under test article and make separate Frequency of test exposures. Ensure that the whole article is • 6 monthly. examined. • As necessary. Evaluation Equipment required • Look for cracks or other abnormal variations of • Items to be tested. density in the image. Method Action • Check effectiveness and condition of fastenings • Items found to be defective should be replaced. on aprons Cif any). • Items being withdrawn can be cut up into smaller • Inspect surface covering for tears or sign of pieces, avoiding the cracked sections. These can deterioration. be used for gonad shielding or shielding parts of • Inspect all seams where appropriate. the film. • Check flexibility, feeling for cracks not seen on • File a report. the surface. • Inspect for cleanliness. • Check apron hanger devices. Viewing box • Assess storage location. A viewing box, or light box, is a simple but important aid to viewing radiographs and is commonly used Evaluation throughout X-ray departments. It consists of an even • General condition and cleanliness. light source of sufficient light intensity to allow opti • Possibility of cracks. mum viewing. • Storage location and hanging devices. Viewing a radiograph under good viewing conditions • Are staff using the apron hangers? is important in order to visualise the maximum amount of information. Regular maintenance and cleaning Action should be carried out (see Appendix A, page 147). All • Initiate any repairs or cleaning required. viewing boxes should: • Carry out X-ray check. MODULE l. ACCESSORY EQUIPMENT 39 • Be conveniently placed. Electrical check • Be safely fixed to a wall or stable mobile This check should be carried out by or under the structure. supervision of an electrician. Switches, fluorescent • Be in good working order. tubes, starters and electrical connections should be • Be of satisfactory design. checked. • Have an all over even light. • Be clean inside and out. • Be electrically safe. • Have an adequate light output. Design • Two parallel fluorescent tubes of equal light out- put, with starters. • A built in, or attached, spotlight is an advantage. • The film anchor should hold the film firmly. • A good quality switch. • Safe electrical wiring. Cleaning Dust on the window or tube will reduce the light out put. Marks on the window can be misleading. Frequency of cleaning • Outside daily. • Inside 6 monthly. Fig 2-9.Viewing box with front window removed Equipment required • Viewing box to be cleaned. Frequency of check • Clean cloth. • 6 monthly. • Screw driver. Equipment required Method • Viewing box to be checked. • Remove plug from power socket. • Screw driver. • Remove the front window. • Clean window on both sides (intensifying screen Method cleaner is a useful cleaning agent as it has anti • Remove plug from socket. static properties). • Remove front window. • Clean the back plate and fluorescent tubes. • Check condition of wiring. • Inspect window for damage. • Check electrical connections. • Make sure that tubes and starters are firmly in • Check stability of switch. place. • Check installation of fluorescent tubes and • Replace window. starters. • Test. • Replace front window. • Replace plug in socket. Evaluation • Test. • Any dust on inside or outside? • Any marks on viewing window? Evaluation • Electrical connections firm? Action • Electt·ical wiring in good condition? • Wipe over with a cloth. • Tubes and starters located properly and • Use spirit to clean window of hard-to-remove working? marks. QUALITY ASSURANCE WORKBOOK 40 • Light source even and comparable to other view Routine care ing boxes? Care of positioning pads should be ongoing. • Replacing fluorescent tubes at different time in • Try to minimise the risk of contamination by: tervals, or with a different type of tube, may pro - Contrast media duce a difference in light intensity from one side of - Plaster of Paris the screen to the other or one viewing box to another. -Blood - Urine Action • Inspect and wash regularly. • Tighten electrical connections. • Do not use for any other purpose. • Refit fluorescent tubes or starters. • It may be preferable to cover with waterproof • Replace tubes or starters if necessary. radiolucent material, or removable cotton covers • If, after replacing only one tube, it is found to be or both. brighter than the remaining one, replace both. The working tube that has been removed can be Positioning pad tests matched with another one at a later date. • Visual • Replace any faulty parts. • X-ray • File a report. Visual test Viewing conditions • Room light levels in the film viewing area should Frequency of test not be too high. • Weekly. • A bright spotlight should be available for viewing • As necessary. dark areas of the film. • The viewing box should be mounted at the cor Equipment required rect height for easy viewing. • Pads to be inspected. • Light source should be even and the same as other boxes. Inspect for: • Likelihood of contamination. • General cleanliness. Patient positioning aids • Shape. Positioning pads • Smell. • Particles breaking off. A useful aid to maintaining the position of the patient. • Firmness. A range of pad sizes and shapes should be available in each X-ray room. They must be radiolucent. Evaluation Sets of firm foam pads are available from manufac • Unhygienic? turers (a polyethylene foam is commonly used). Pads • Likelihood of contamination by radio opaque sub may be improvised using other materials but they must stances? be checked for radiolucency. • Shape, firmness, general deterioration? Action • Wash and re-test if necessary. • If there is a likelihood of contamination with a ra diopaque substance then carry out the X- ray test. • If the pad has deteriorated to the extent that it no longer fulfils its function effectively then re place it. • File a report. X-ray test Frequency of test Fig 2-1 0. Positioning aids-selection of foam • 6 monthly. pads, sand bag & polystyrene block • As necessary. MODULE 2. ACCESSORY EQUIPMENT 41 Equipment required If the band is plastic, simply wipe over • X-ray unit. with a damp cloth. The ratchet and fix • Pads to be tested. ing mechanisms should be inspected • Loaded cassettes as necessary. and tested six monthly or as necessary. • Lead marker. The band should also be tested every six months, or as necessary, for radio Method paque substance contamination. • Place a loaded cassette on the tabletop face Water Bottle Empty fixer or developer bottles full of up. water are useful as cassette supports, • Place the pad on the cassette (ensure that the or in weight bearing views of ale joints. cassette is big enough to cover whole pad). Water is relatively radio-opaque. Little e Set a FFD (SID) of lOO cm. care is required, simply wipe over the • Collimate to cover the pad. outside of the bottle with a damp cloth • Place the marker in one corner of the X- ray field as necessary. Ensure that the lid is on (note which corner of the pad it relates to). tightly and that the bottle does not • Set an exposure of 50 kV and 6 mAs. leak. • Expose. • Polystyrene blocks used to pack equipment can • Process the film. be cut to required shapes. • Polystyrene chips used in packing can be sealed Evaluation into suitable sized cotton or linen bags. • Look for radio opaque shadows within the • Cardboard boxes can be cut down to suitable sizes pad. and shapes and re-stuck. • Wooden blocks can be cut to shape. Action • Folded blankets can also be useful. • If radiopaque shadows are detected, wash and dry the pad. Note: It should be remembered that any improvised • Re-test. positioning aid must be checked as to its radiolucency • If opacities are still seen, replace the pad. before use. • Continued use of the pad may be considered, pro vided it is identified as containing radiopaque Patient measuring callipers material and not used where it might show on the films. Measuring callipers are a simple device that allow easy • File a report. and accurate measurement of a body part. Calculating radiographic exposure factors can be made more accurate by relating them to the thickness Other positioning aids of the body pat't (see Module 6. Radiographic expo A range of materials can be used to assist in position sures, page 124 and Appendix A, page 135). In order to ing the patient in specific positions, some radiolucent do this, it is more convenient to use measuring calli and some not. pers. Care should always be taken to ensure that radio paque positioning aids do not obscure the image. Care • Handle with care as they are easily bent or Sandbags These are radiopaque. They should have broken. waterproof or removable cotton or linen • Any distortion may mean that they are no longer covers that must be washed regularly. accurate. Flour bags Similar to sandbags but are radiolu • Store in a safe but convenient place. cent. They mould to different shapes • Clean regularly. more readily, but are not so heavy as sandbags. Callipers accuracy test Compression If the band is linen, detach from the Frequency of test band end fixing mechanisms and wash as • Monthly. necessary. • As necessary. QUALITY ASSURANCE WORKBOOK 42 Equipment required Evaluation • Callipers to be tested. • The measurements should be accurate to within • Measuring device. +or -2mm. Method Action • Check that the moveable arm is not loose. • If the measurements are not accurate, carefully • Measure the distance between the outer ends of bend the arm. the two arms at minimal, mid and maximum • If the arm is loose, attempt to tighten it. If un distances. able to correct faults, arrange to have it repaired • Repeat these measurements at the base of the or replaced. arms. • File a report. • Check against scale. MODULE 2. ACCESSORY EQUIPMENT 43 Notes QUALITY ASSURANCE WORKBOOK 44 TASK3 Collimator Several staff have had to repeat films because they have coned off part of the image. The problem seems to be associated with one X-ray room only. What would you do? a) Select an X-ray room and carry out the test you think is appropriate. b) Give a brief summary of what you did. c) Write a report of your findings. d) Recommend appropriate action, if any. e) Write your report below. f) If there is insufficient space, use additional sheets of paper and attach. Brief summary of procedure Report MODULE 2. ACCESSORY EQUIPMENT 45 Recommendation for action, if any Include any test films with this report Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor QUALITY ASSURANCE WORKBOOK 46 TASK4 Changing a collimator light bulb The light in the collimator does not work. You suspect a blown bulb. a) Select a collimator and carry out the appropriate remedial action. b) Answer the following questions in the spaces provided. c) Ask your tutor or an electrician to supervise your actions. l. What type of light bulb in use?------ 2. Does this bulb have to be fitted a certain way round? YES/NO 3. If YES, describe this:------ 4. Where are the spare bulbs kept?------ 5. Is a correct spare readily available? YES/NO 6. Who supplies the spare bulbs? ______ Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor MODULE 2. ACCESSORY EQUIPMENT 47 TASKS Film/screens You have detected a localised area of unsharpness in an image, carry out the test you would do to investigate the problem. a) Select any cassette and carry out the appropriate test. b) Briefly describe the test you carried out. c) Report on your findings. d) Recommend any action you consider necessary. e) Write your responses in the spaces provided. Brief description of test carried out Report on your findings Recommended action Include your test film with this report Tutor's comments: Satisfactory/Unsatisfactory Sigature Date Tutor QUALITY ASSURANCE WORKBOOK 48 TASK6 Intensifying screens The densities of your radiographs have not been consistent.You are confident that your choice of exposures and the X-ray equipment is not the problem. You suspect the problem may lie with the efficiency of some of your screens. a) Select any three cassettes of similar size, fitted with the same type of screens and using the same type of film. b) Carry out the appropriate test to check the consistency of those screens. c) Briefly describe the test you carried out. d) Inspect the resultant films and make a report on your findings. e) Recommend any action you consider necessary. f) Write your responses below in the spaces provided. Brief description of test carried out Report of your findings Recommended action Include your test films with this report Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor MODULE 2. ACCESSORY EQUIPMENT 49 TASK? Stationary grid It is time to carry out the regular QC checks on your stationary grids. (a) Select a stationary grid. (b) Carry out the appropriate stationary grid tests/checks. Cc) Answer the questions below, in the spaces provided. l. Record the grid specifications: Grid Ratio------ Grid Line------Focal Range ______ 2. Is the tube side identified? Yes/No 3. How was the tube side identified? 4. Is the direction of the lead strips indicated? Yes/No 5. How was the direction of the lead strips indicated? 6. Write your visual report here 7. Write your evaluation of the X-ray image here QUALITY ASSURANCE WORKBOOK 50 8. What action do you recommend? Include your test films with this report Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor MODULE 2. ACCESSORY EQUIPMENT 51 TASKS Lead rubber apron and gloves It is time to carry out the regular QC checks on your lead rubber items. a) Select a lead rubber apron and pair of gloves. b) Carry out the appropriate tests/checks. c) Answer the following in the spaces provided. 1. Write your visual inspection report: General Condition: Cleanliness: Possibility of Cracks: Storage Location: Hanging Devices: Staff use of Hanging Devices: 2. Write your test report: QUALITY ASSURANCE WORKBOOK 52 3. Write your recommendations for action, if any Include your test films with this report Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor MODULE 2. ACCESSORY EQUIPMENT 53 TASK9 Viewing box It is time to carry out your routine QC checks on your viewing boxes. a) Select a viewing box. b) Carry out the appropriate procedures. c) Ask your tutor or an electrician to supervise this. d) Answer the following questions in the spaces provided. l. Is the viewing box • Conveniently placed? YES/NO • Safely fixed to the wall/mobile structure? YES/NO • In good working order? YES/NO • Of satisfactory design? YES/NO 2. Does it have • An adequate light output? YES/NO • An all over even light? YES/NO What action would you recommend, based on your answers above? Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor QUALITY ASSURANCE WORKBOOK 54 TASI< 10 Positioning pad inspection It is time for the regular QC checks of your positioning pads. a) Select any one positioning pad. b) Carry out the appropriate tests/checks. c) Answer the following questions in the spaces provided. l. Write a visual inspection report General Cleanliness Likelihood of radiopaque contamination Shape Firmness Smell 2. Write your X-ray test report 3. Write your recommended action, if any MODULE l. ACCESSORY EQUIPMENT 55 Include your films with these answers Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor QUAliTY ASSURANCE WORK~OOK 56 MODULE 3 X-ray equipment Aim 11 Alignment. ll FFD (SID). To provide the technical information and testing rou tines that will allow simple care, maintenance and test X-ray table ing to be carried out on basic X-ray equipment. To Ill Mechanical. provide an insight into the choosing and accepting of 11 Electrical. basic x-ray equipment. 11 Alignment. Objectives Tomography On completion of this module the student will have the 11 Mechanical. technical knowledge and practical skills to carry out 11 Electrical. simple cleaning, maintenance and testing on: ll Cut (layer) level. 11 Image quality. Generator 11 Radiation output reproducibility. Potter bucl The term "X-ray equipment" covers generator, tube, • kV, mA, time ranges. cables, control panel, table, tube stand and bucky. • Tube mounting (overhead or column). Specific types of equipment considered are general • Table (tilting, fixed, floating top, bucky). purpose, tomography, portable and mobile. • Upright bucky. It is important to ensure that all equipment is worl< • Anticipated patient through put. ing efficiently and accurate records are kept (see Appendix A, pages 133 to 137). Resources available • Power. Choosing X-ray equipment • Space. • Maintenance and repair. Identify your need • Finance. • General purpose, fluoroscopy, specialised, mobile. Manufacturer warranty • Generator (design/output). • Warranty period. • To suite power supply. • Warranty cover. • Determine responsibilities. MODULE 3. X-RAY EQUIPMENT 57 Supplier service • Fluctuations in the main electrical supply. • Installation. • Inconsistency or inaccuracies in kVp, mA and • Initial QC tests. time. • Maintenance. • Repairs. Fluctuation in main electrical supply • Parts. Most X- ray units have a mains compensator that auto • Speed of response. matically compensates for mains fluctuations. Howevet; in some less sophisticated units this must be done by Making the choice hand. The radiographer must always check the mains • Establish your specification requirements. compensator meter before making an exposure and • Review manufacturer's specifications. make any corrections necessary. • Make a short list of suitable equipment. • Submit your requirements to the selected manu Radiation output reproducibility test facturers for quotations. To check that the radiation output is consistent when • Review quotations. identical exposures and conditions are used. • Make selection. Frequency of test Ensure that you have the written agreement of the • At the start of a quality control program. manufacturer or supplier, to supply and install the equip • Yearly. ment chosen, at the price quoted and that there are • As necessary. no hidden extras. Equipment required Acceptance of new X-ray equipment • A water phantom, consisting of a plastic flagon or bucket filled to a depth of lOcm (see Appen Upon completion of the installation and before accept dix A, page 133). ing responsibility for the new equipment, you must • Two sheets of lead rubber. check that • One 24 x 30 cm loaded cassette. • Specifications of equipment installed are the same as that ordered. Method • Installation has been carried out as stated in the • Place the cassette face up on the X-ray table. contract. • Cover three quarters of the cassette with lead • Installation is complete and equipment is work rubber, crosswise, leaving an end section ing efficiently and to your satisfaction. uncovered. • All QC tests have been carried out and are e Set a lOO cm FFD CSIDl. satisfactory. • Collimate the beam to cover the uncovered section. • All accessory equipment has been supplied and is in good order. • Place the water phantom over the area to be • Operating manual has been supplied and is the irradiated. correct one. • Set an exposure that will produce a low density on the film (density of 1). 80 kV and a low mAs is Only when you are sure that the installation has been suggested. It should be just possible to read news carried out satisfactorily should you sign the ac paper print through the density produced (you ceptance papers. may find it necessary to experiment before start ing the test). Generator • Check that the mains compensator is correctly set. A generator is part of the electrical system of an X-ray • Make an exposure. machine which determines radiation output. Any in • Repeat this procedure for each of the remaining consistency in radiation output will adversely influence three sections. Making sure that you have identi the quality of the radiograph. cal conditions. When placing the lead rubber al The kV, mA and time must be consistent on all set low for a space of about 2 mm between each tings. Many factors can influence the radiation output. exposed area. The ones to be considered are: • Process the film. QUALITY ASSURANCE WORKBOOK 58 • The same cassette should be used each time the • Use three exposures with the same kV and mAs test is carried out. values, but differing combinations of mA and time. Evaluation • Suggested exposures: (you may find it necessary • Compare the densities. If you have a densitom to experiment before doing the test) eter, take readings from the centre of each im - Exposure 1: 80kV 10mAs (SOmA 0.2sec) age and compare these too. - Exposure 2: 80kV 10mAs ClOOmA 0.1sec) • The conditions for all four exposures were identi - Exposure 3: 80kV 10mAs (200mA 0.05sec) cal; therefore all densities should be the same. • If they are not then the unit is not producing a Evaluation consistent output. • Despite the fact that the mA and time vary, • Compare with any previous test films. the mAs value remains the same, as does the kV, therefore all film densities should be the Action same. • If the densities are not the same repeat the test • If the densities are not the same, then it must at different times of the day. Mains fluctuations be assumed that one or more of the exposure may be the problem. factors are inaccurate or inconsistent. • If the densities remain inconsistent, call the X • By varying the mAs and time factors, but retain ray engineer. ing the same m A and kV values as before, it should • If the inconsistencies are minimal continue to use be possible to identify which of the factors is at the unit. fault. • If the inconsistencies are unacceptable, then stop • If the out of step density in each test was the using the unit until the fault has been corrected. second exposure ClOO mAl, this indicates that the • Mark all films with date and time, and keep for fault lies with the 100mA setting. reference. e.g. 80 kV 50 mAs (50 m A l.O sec) • Record exposure factors, FFD (SIDl, water phan 80kV SOmAs ClOOmA O.Ssec) tom details, size of the X-ray field, cassette number 80 kV 50 mAs (200 mA 0.25) and type of film used, for future reference. • kV and time checks should be carried out in con • File a report. junction with this test. Constancy of radiation output at different Action mA settings test (see Appendix B, page 155) • Repeat the test several times, varying the expo A test to check the reliability of the mA and time set sures, but always keeping the kV and mAs con tings (most importantly the mAl. The photographic ef stant, within any one test. fect for a given mAs value should remain constant even • If the densities continue to be inconsistent, call though the mA and time factors may be varied.AII other an X-ray technician. factors being constant. • If the inconsistencies are minimal continue to use the unit. Frequency of test • If the inconsistencies are large, stop using the • At the start of a quality control program. unit until the fault has been corrected. • Yearly. • Mark all films with date, time and exposures and • As necessary. keep for reference. • Record exposure factors, FFD (SIDl, water phan Equipment required tom/step wedge details, size of X-ray field, cas • A step wedge or10 cm water phantom, as used in sette number and type of film used. previous test (see Appendix A, page 133). • File a report. • Two sheets of lead rubber. • One 24 x 30 cm cassette. Accuracy of timer test A test to check the accuracy of the X-ray unit timer. Method This test should only be carried out on a 1 or 2 pulse • Carry out the procedure used for the reproduc unit. Timers of 3-phase and capacitor discharge units ibility test (see page 34), with the following cannot be checked by this method. exceptions. MODULE 3. X-RAY EQUIPMENT 59 • The accuracy of the timer is checked by counting the number of spots. • If the mains supply has a frequency of 50Hz (50 cycles per second): - A one-pulse (self rectified) unit will generate 50 pulses of radiation per second (50 spots on the film). - Therefore a 0.1 sec exposure should produce 5 spots (see Fig 3-2). Fig 3-l.Accuracy of timer test using spinning top Frequency of test • At the start of a quality control program. • Yearly. • As necessary. Equipment required Fig 3-2. Spinning top image of a single pulsed • Manually operated spinning top (see Fig 3-1 and unit using a 50Hz mains supply Appendix A, page 135). • One loaded 24 x 30 cm cassette. • Two sheets of lead rubber. - A two-pulse (full-wave rectified) unit will gen erate 100. pulses of radiation in one second Method ClOO spots on the film). • Place the cassette on the X-ray table face up. - Therefore a 0.1 sec exposure should produce • Place the spinning top in one quarter of the 10 spots (see Fig 3-3). cassette. • Cover the other three quarters of the cassette with lead rubber. • Set a 100 cm FFD CSID) and collimate to cover the spinning top. • Set an exposure of 70 kV, lOO mA and a time of 0.1 sec. • Manually spin the top. After it has settled to a medium speed, make an exposure (it may be necessary to experiment before starting the test). • Repeat the process on each of the remaining Fig 3-3. Spinning top image of a two pulsed quarters of the film. unit using a 50Hz mains supply • Process the film. Evaluation • The film will show four images, each having a • If a mains supply has a frequency of 60Hz (60 series of spots forming an arc. cycles per second): • The distance between the spots is not important - A one-pulse unit will generate 60 pulses as this only represents the speed at which the of radiation per second (60 spots on the disc rotates. fiim). • The spots should easily be counted, so do notal - A 0.1 sec exposure will produce 6 spots (see low the spots to complete a circle and overlap. Fig 3-4). QUALITY ASSURANCE WORKBOOK 60 Note • Three-phase and capacitor discharge units will show a continuous line image (see Fig 3-6). Fig 3-4. Spinning top image of a single pulsed unit using a 60Hz mains supply - A two pulse unit will generate 120 pulses of radiation in one second (120 spots on the Fig 3-6. Spinning Top Continuous line Image film). - A 0.1 sec exposure will produce 12 spots (see • These images are of no value in checking the timer. Fig 3-5). • The capacitor discharge unit may show a con tinuous line image of reducing density. • If your unit is the type that produces a line of reducing density,you may wish to do spinning top tests on the three highest time settings. Study the low density end of the line. If the density is very low, the radiation at that exposure time is of little value in image production and only adds to patient dose. Consider not using that setting. Fig 3-5. Spinning top image of a two pulsed Accuracy of kVp test unit using a 60Hz mains supply To check that the generator is producing the kVp set on the control panel. This can be carried out by using a kVp meter or a kVp test cassette. One of the most • Other exposure times will produce a different widely used is the Wisconsin peak kilovoltage test number of spots. cassette. Action Using a kVp meter • If the number of spots on the images is different from the number expected, the timer may be in Frequency of test accurate. Repeat the test using different time • When the equipment is first installed. settings. • Yearly. • If the number of spots on all four images on the • As necessary. film is the same, but different from the number expected, the fault wou Id seem to be consistent. Equipment required The unit can still be used, but compensatory • kVp meter. changes to exposures must be made. • Generator to be tested. • If the number of spots on the images is not the same, the fault would seem to be inconsistent. A Method decision must then be made whether to use the • Place the sensor in the middle of the X-ray beam unit or not. at a FFD CSID) of lOO cm. • If the fault appears to be related to a specific • Collimate to a standard area sufficient to cover time setting, the unit can continue to be used, the sensor. avoiding this time setting. • Take readings at 10 I • Repeat this procedure for each tube focus Method available. • Place the cassette on the tabletop, face up (side marked with kVp divisions) and long dimension Evaluation of the cassette parallel to the anode-cathode axis. • Compare each kVp reading with the appropriate • Set a lOO cm FFD (SIDl. kVp setting. • Collimate to the area of the cassette marked with • The measured kVp must be within+ o1· -5 kVp o1· the lowest kVp (60 kVpl. 5%. • Set a kVp of 60. • Set an mAs value that will give a density of ap Action proximately l in the region of the dots (you may • If the measured kVp s do not fall within the ac need to experiment). ceptable limits, call an X-ray engineer. • Shield the remainder of the cassette with lead rubbe1·. Using a kVp test cassette • Make an exposure. • Expose each of the othe1· section of the cassette Frequency of test (marked 80, lOO and 120 kVpl separately, using • When equipment is first installed. the appropriate kVp each time. • Yearly. • The time setting should be adjusted for each ex • As necessary. posure, to maintain an optical density of l in the region of the dots each time. The mA remains the Equipment required same for each exposure. • Loaded kVp test cassette (see Fig 3-7 (a)). • Remember to adjust the lead rubber each • Two sheets of lead rubber, one 10 x 23 cm and time. the other 23 x 23 cm. • Test cassette calibration graphs for each kVp level used. • Densitometer. Approximate mAs settings kVp Single phase unit Three phase unit 60 500 400 80 75 40 lOO 15 10 120 12 8 Joel E Gray et al, Quality Control in Diagnostic Imaging. • Pmcess the film. • Repeat this p1·ocess at low, mid and high mAs settings. (a) Evaluation • On the 1·adiog1·aph the regions are identified as A (60 kVpl, B (80 kVpl, C (lOO kVp), D (120 kVp). • Each k'lp region contains two columns of clots (see Fig 3-7 (bll. • The ho1·izontal rows are numbe1·ecll to 10,1 be ing at the darker end of the column. • One column of dots is of uniform density, in each region, and is called the reference column. • The clots in the other column, in each region, will show a density gradient, darkest at the top (b) (120 kVp i'egion) and lightest at the bottom Fig 3-7. (a) kVp test cassette, (b) test cassette (60 kVp region). image of one kVp region QUALITY ASSURANCE WORKBOOK 62 • Look for a density match between the two col Action umns, in each region. This should be done with a • If the measured kVp s do not fall within the ac densitometer. cepted limits, call an X-ray engineer. • If an exact match is not found an average must be determined using the following method. Control panel check Frequency of checl< Example: • Yearly. Step No. Optical density Optical density • As necessary. of step of reference 5 1.40 1.15 Equipment required 6 1.10 1.15 • Control panel to be checked. 1 15 0 25 Match step 5 = 6 + .4°- 1. = 5 + · = 5.38 1.40- 1.10 0.30 Method • Check that all meters are working and all illumi • When a match has been determined for each nated panels are lit. region, refer to the calibration chart for the ap • Check that all knobs, switches and buttons are propriate region (charts for each of the four kVp firmly attached and work effectively. regions are supplied with the cassette). • Check that all read outs are visible and are • The chart will have two graphs on it, one for a accurate. single phase unit and one for a three phase unit • Check that all signage is readable and correct. (see Fig 3-8) • Check that hand switch operates effectively and is not damaged. • Check that the cable to any extension hand or 10 foot switch is not damaged or showing signs of wear and that the electrical connections are 9 Three phase secure (exposure switches on cables are not 8 recommended). 7 Action Step No. 6 • Correct any simple faults. • For more complicated faults call an X-ray 5 engineer. 4 • Inform staff. • File a report. 3 Single phase 2 X-ray tube and high voltage cables check Frequency of checl< 1 • Yearly. 0 • As necessary. 50 60 70 80 90 lOO llO 120 kVp Equipment required Fig 3-8. kVp test cassette calibration chart, • Equipment to be checked. suitable for region C (I 00 kVp) Method • Check that the tube is securely fixed to its sup • Using the appropriate graph, plot the match step port and that any movement locks are working level for each kVp region on the vertical axis, then effectively. read off the corresponding kVp s from the hori • Check that the collimator is securely fixed to the zontal axis. These kVp s shou Id, correspond to the tube and that it rotates freely. kVp s used. • Inspect the high tension (HTI cables. • The measured I firmly fixed and that the cables lie in them cult to adjust accurately. This test can also be applied correctly. to the upright Bucky. - Check that the cables hang freely, do not catch on anything and extend to their required Frequency of test limits without unnecessary tension. • Yearly. • As necessary. Evaluation • Anything that is damaged, considered unsafe or Equipment required has potential for wear or damage should be cor • Equipment to be tested. rected as soon as possible. Method Action • First check the alignment of the light field and • Correct any simple faults immediately. X-ray field in the collimator (see Module 2, • For more complicated faults, call an X-ray Accessory equipmen( page 30). If an error is engineer. found this must be corrected before starting • Inform staff. further tests. • File a report. • Ensure that the tube is perfectly straight. • Switch on the collimator light. X-ray tube, column, table and • Lower the tube until the window of the collima upright bucky tor is just above the table top. • Adjust the tube until the centre line of the light Locks and movements check field is on the centre line of the table. Frequency of check • If you have a floating top table, centre the tabletop first. • Yearly. • Check to see if the automatic centring notch on • As necessary. the tube arm has been located, if there is one. Equipment required • Move the tube to the top of the column. • Equipment to be checked. • Look to see if the centre line of the light field has moved away from the centre line of the table. Method e Set a FFD (SID) of lOO cm. • Test all movement locks for effectiveness and ease • Angle the tube up and down the table, watching to see if the centre line of the light field remains of use. • Test the freedom of movement of the column on the centre line of the table. . along the floor and if it travels the full length of • Re set the X- ray beam at 90 a to the tabletop . the track. • Move the tube column from end to end of the • Any ceiling tracks should be tested in the same table, watching to see if the centre line of the way. light field remains on the centre line of the table. • Look for any wear or damage. • Check for loose or missing screws, bolts or Evaluation fittings. • If the centre line of the light field does not re main on the centre line of the table during tube Action movement there is an alignment problem. • Correct any simple faults immediately. • If the centring notch cannot be located when • For more complex faults, call an X-ray engineer. the tube is correctly centred to the table there is • Notify staff. · an alignment problem. The possible causes are: - The X-ray tube has slipped in its mounting. • File report. - The tube column is not vertical. Alignment of X-ray beam to table test - The cross arm (if there is one) is not The X-ray beam must be perpendicular to the tabletop, horizontal. when in the normal over-couch position. Most X-ray - The tube column track is not parallel to the tube mountings allow limited angling across the table. table. The lock for this movement sometimes slips, or is diffi- - The table is not level. QUALITY ASSURANCE WORKBOOK 64 - The centring notch is wrongly located. Method - The tube column track is the wrong distance • Place the spirit level horizontally on the centre from the table. line, at one end of the table. • Note the position of the bubble. Action • Rotate the spirit level through 90°. • Carry out the following tests to determine the • Note the position of the bubble. exact cause of the problem. • Repeat this procedure at the other end of the table. Check that column is vertical test • The bowl of water can be used instead of the spirit level by measuring the height of the water Frequency of test surface above the table around the bowl. • Yearly. • As necessary. Evaluation • If the spirit level bubble is not centred, the table Equipment required is not level. • Spirit level with vertical capability, or a plumb • If the surface of the water is not parallel to the bob (weight on a length of string) tabletop, the table is not level. • Equipment to be tested. Action Method • If the fault is a problem, it may be possible to put • Hold the spirit level vertically against the side of packing under the legs or base of the table or the tube column and note the position of the call an X-ray engineer. bubble. • File a report. • Move the spirit level a quarter of the way around the column and repeat the procedure, or Check that the cross-arm is horizontal • Hold the end of the string high against the cen tre of the column so that the weight holds the Frequency of test string straight and unobstructed. • Yearly. • Check to see if the string and column are • As necessary. parallel. • Move the string a quarter of the way round the Equipment required column and repeat the procedure. • Spirit level or a metre rule. • Equipment to be checked. Evaluation • If the spirit level bubble is not centred, the col Method umn is not vertical. • Place the spirit level on the top of the cross-arm, • If the string is not parallel to the column, the or hold against the underside of the cross-arm. column is not vertical. Note the position of the bubble, or • Measure the distance from the cross-arm to Action the table top at the front and back of the • Call an X-ray enginee~ to make adjustments. cross-arm. • File a report. Evaluation Check that the table top is horizontal • If the spirit level bubble is not centred, the cross arm is not horizontal, or Frequency of test • If the two measurements are not the same, the • Yearly. cross-arm is not horizontal. • As necessary. Action Equipment required • If the misalignment is considered to be a prob • A spirit level or an improvised system (bowl or lem, call an X-ray engineer. bucket of water) can be used. • Notify staff. • Large diameter bowl or bucket and a ruler. • File a report. • Equipment to be checked. MODULE 3. X-RAY EQUIPMENT 65 Test alignment of X-ray beam to Action upright bucky • Inform staff of any inaccuracies if the problem • It is usual to align an upright bucky against a cannot be corrected immediately. wall in line with the end of the X-ray table. • Temporary corrections could be made by stick • If this is so, it is useful to have the centre line of ing a strip of adhesive plaster over the scale and the upright bucky in line with the centre line of accurately re marking the scale. the table. • Arrange to have pointers or scale moved to cor • The tube can then easily be angled from the rect location. table to the upright bucky. • If only one pointer is fitted, arrange for a second • Similar alignment tests to those carried out on to be fitted or notify staff of the adjustment nec the table can be used. essary when setting the FFD CSID). • File a report. Test accuracy of FFD (SI D) scale • Carry out the test again after remedial work has Many basic fixed X-ray units have a scale fixed to the been completed. tube column. This allows the radiographer to easily set the FFD CSID) above the table. Tomography A pointer is fixed to the tube arm mounting, allow accurate measurement to the tabletop.There may be a A system which allows prolonged exposures whilst tube second pointer giving the FFD CSID) to the under table and bucky move in harmony. bucky tray. If there is no second pointer it will be nec In simple linear tomography the tube and bucky are essary to measure the table top to bucky distance and connected by an arm, the centre of which is pivoted. make allowance when using the bucky. The height of the pivot above the tabletop determines the level of image clarity, while all other levels appear Frequency of test blurred. • Following new installation The size of the angle of swing determines the thick • Following any changes to equipment. ness of cut. The bigger the angle the thinner the cut, • As necessary. the smaller the angle the thicker the cut. It is a useful technique in blurring out unwanted Equipment required parts of the X-ray image. It can be a dedicated unit or • Tape measure. an attachment to a general-purpose X-ray unit. • Equipment to be tested. Mechanical and electrical check Method Frequency of check • Check to see if there is a pointer and that it is • Each time the tomographic equipment is set up firmly attached and pointing at the correct angle. if an attachment • Adjust the pointer if necessary. • Yearly if a dedicated unit. • Measure lOO cm from focal spot location dot, on the tube housing, to the tabletop. Equipment required • Check to see if the pointer is on the lOO cm mark • Tomographic unit to be checked. on the scale. • If there is a second pointer measure lOO cm from Method the dot on the tube to the bucky tray. • Check to see if the correct pointer is on the Inspect: lOOcm mark on the scale. • Fulcrum attachment attaches securely to the • If there is only one pointer, record whether it table. measures to the tabletop or bucky. • Connecting arm attaches securely to the bucky • Record the measurement from the tabletop to and tube. the bucky tray. • Connecting arm pivots correctly. • FFD CSID) readout displays can be checked in • Cut height adjustment moves freely. the same way. • Tube mounting column runs freely on tracks. • Electrical cable, connections and plugs. Evaluation • Tomography ON/OFF switch. • Any inaccuracies require remedial action. • Carry out a test run. QUALITY ASSURANCE WORKBOOK 66 Evaluation Method • Electrical cables, switches and plugs fitted prop • Set up the tomography equipment. erly and show no signs of wear. • Place the cassette face up in the bucky. • Mechanical parts move freely and show no signs • Set an exposure of about 50 kV, lowest mA and a of wear. normal tomography time. • Locks effective. • Place the phantom longitudinally (nails at 90° to • Drive motor works effectively. the direction of tube travel) on the centre line of • Cut height adjustment works effectively. the table, directly over the middle of the cassette • No tube vibration during travel. when the X-ray beam is vertical. • Collimate to cover the phantom. Action • Set the fulcrum height. • Correct any minor faults. • Place a lead marker within the light field, indi • Call an X-ray engineer for more complex faults. cating the height of the fulcrum. • File a report. • Position the tube column in its normal start position. Cut (layer) height accuracy test • Make an exposure. • Observe movements. Frequency of test • Process the films. • Yearly. • As necessary. Note: MESH TEST TOOL-must be placed at 45 o to the line of tube travel, otherwise there will be incom Equipment required plete blurring of the wires running in the same direc • Tomography test tool (see Fig 3-9, Fig 3-10 and tion as that of the tube travel. For ease of use, a wire Appendix A, page 136). should be taped across the mesh at the height of the • One 18 x 24cm loaded cassette. fulcrum. NAIL TESTTOOL-note the number of nails in • Equipment to be tested. the row at the height of the fulcrum. Evaluation • Study the image. In linear tomography there should be one area of clearly defined, in focus, mesh, or row of nails, with the remainder of the image on either side being blurred. • Note the height of the sharply defined area in the image and check against the actual cut height. Within + or -5 mm is acceptable. Action • You may wish to repeat the procedure with dif ferent fulcrum heights. Fig 3-9.Tomography test tool using nails • If the clearly defined image height and set height do not coincide, carry out the test again to make sure that no errors have occurred. • If the inaccuracy is still present call the X-ray engineer. • If the inaccuracy is consistent, the unit can con tinue to be used, with appropriate temporary changes made to the scale. • If the observed movements were not smooth, fur ther investigation is necessary. • File a report. Cut thickness accuracy test Although this is not a highly accurate assessment of Fig 3-1 0. Tomography test tool using mesh cut thickness, it is still quite useful. The wire mesh test MODULE :J. X-RAY EQUIPMENT 67 tool is more suitable for this test (see Appendix A, page of the central darker spot indicate that the tube 136). A similar test is carried out to that described for is not travelling the full length of its travel, either the "cut height" test. Repeat the test using different at the start or end of its movement. angles of swing, if available. Action Evaluation • Check that the equipment is set up correctly and • Measure the depth of the clearly defined areas there is nothing obstructing its travel. · of mesh and compare. • If the fault is still present call an X-ray engineer. Note: this test can also be used to check the angle of Action swing by using the formula • If the cut thickness does not appear to be what it should be, call an X-ray engineer. Tan 8 = ~ Where a = the distance between the lead sheet and Pinhole trace test the film The quality of the image can be assessed by using the b = the distance between the one end of the pinhole trace test image to the central darker spot. 8 =the angle formed by the central ray when Frequency of test vertical and when at the furthest point of • Yearly. its travel during the exposure. • As necessary. Checking the radiation output Equipment required • Use a similar test to that described under • A sheet of lead, approximately 150 mm x 150 mm, Pinhole Trace test (see page 57). with a 2 to 3 mm diameter hole drilled in the • If the density of the black line is regular through centre. out (except for the black dot in the middle) the • One 18 x 24 cm loaded cassette. radiation output is considered to be consistent. • Rule or tape measure. • If there is some variation in density then the ra diation output has not been consistent. Method • This is not an accurate test, but does give some • With the central ray vertical, place the cassette idea of radiation consistency. on the table top, face up, so that the central ray is directed to the middle of the cassette. Cleanliness of equipment • Position the lead sheet at the same height above Cleaning equipment should be treated as part of the the table top as the fulcrum, with the pinhole quality assurance program. Regular cleaning of all directly over the middle of the cassette. equipment is very important from a hygiene and work • Collimate to the hole in the lead. environment point of view. • Make an exposure with the tube stationary. • With the same cassette still in position, make a Frequency of cleaning second exposure while the tube moves through • Daily its cycle. • As necessary. • Process the film. Equipment required Evaluation • Clean cleaning cloths. • The radiographic image should be a black line with straight sides and of even density, with a Method darker spot in the middle of it. The distance from • Wipe over all equipment surfaces using a dry the ends of the black line to the darker central cloth. spot should be equal. • If dirt/marks on non electrical equipment cannot • An uneven image indicates vibration of the tube be removed, dampen the cloth slightly with water. during movement. • Be very careful when using liquids near any elec • Uneven densities in the image indicate variations trical apparatus as most liquids are good con in the speed of tube travel. ductors of electricity and may cause a short and • Differences in the length of the image either side equipment damage. QUALITY ASSURANCE WORKBOOK 68 • Methylated spirit or cleaning fluids may be used Grid movement test with care, if necessary. The grid in a potter bucky is designed to move from side to side during the exposure, when switched on. Action Movement may be too fast, too slow, erratic or not take • Keep records of daily cleaning routines. place at all. • Record condition of equipment. Frequency of test Potter bucky • Yearly. • As necessary. Mounted under an X-ray table, or in upright form, it consists of a cassette tray, above which is mounted a Equipment required grid, which move during the exposure. Provides the • Bucky to be tested. benefits of a grid, but with the movement diffusing out • One.35 x 43cm loaded cassette. the image of the gridlines. Method Operation test • Place the cassette, face up, in the bucky tray and Frequency of test push the tray in. • Yearly. e Set a lOO cm FFD (SIO). • As necessary. • Centre the X-ray beam to the bucky and colli mate to cover the film. Equipment required • Set an exposure to give a density of 1 (ap • Potter-Bucky to be tested. proximately 55 kV 20 mAs). You may need to experiment before carrying out the test. Method • Switch the bucky on. • Check bucky movement on mounting rails. • Make an exposure. • Check efficiency of locks. • Process the film. • Check bucky tray movement and cassette clamp. • Check that grid movement takes place during Evaluation exposure. • If there is an even, clear pattern of grid lines over • Remember that this is a test. Close the collima the whole of the film the grid did not move at all, tor shutters and direct the X-ray beam well away or moved too slowly, orfor only part of the exposure. from the person carrying out the checl<. • If there is an uneven pattern of grid lines over the film the grid moved erratically. Action • If the grid lines could not be seen, the grid moved, • If bucky does not run freely on rails: as it should. - Look for obstruction and free it. - Lubricate rails. Action - Request replacements if appropriate. • Check to see if anything is stopping the grid • If locks are faulty: movement. - Adjust or request replacement. • Check the cable and electrical connections. • If bucky tray movement is faulty: • Re test. - Look for obstruction. • If you have been unsuccessful call an X-ray - Lubricate. engineer. • If cassette clamp is faulty: • Inform staff. - Adjust and/or lubricate. • File a report. - Repair or request replacement. • If grid movement appears to be erratic, carry out Cassette centered to the middle of the grid movement test. bucky test • If it is not possible to fix the problem, call an X Frequency of test ray engineer. • Yearly. • File report. • As necessary. MODULE 3. X-RAY EQUIPMENT 69 Equipment required • Bucky to be tested. • Marker (small coin). • One 35 x 43 cm loaded cassette. Method • Place the cassette in the bucky tray face up. • ~heck that cassette clamp is firmly and correctly closed. (a) • Push bucky tray fully in and lock bucky in position. e Set a FFD (SID) of lOO cm. • Centre the beam to the middle of the table. • Adjust the bucky so that the central ray coin cides with the centreline of the cassette. • Place the marker on the tabletop so that it coincides with the centre of the X-ray beam. (b) • Adjust the collimation to cover the cassette. Fig 3-1 I. Central ray centered to the middle • Make an exposure. of the bucky test, (a) shielding in place ready • Process the film. for first exposure, (b) test tool in place prior to covering holes Evaluation • The marker should be in the middle of the film. • Measure from the image of the coin to all four Method sides of the film. • Switch on the bucky. • P!ace the cassette crosswise in the bucky Action tray. If coin image is not in the middle of the film. e Set lOOcm FFD (SID). • Check bucky tray movement. • Center the tube to the center of the bucky. • Check cassette clamp. • Place the test tool crosswise on the tabletop so • Adjust as necessary that the central hole (the one with the two small • If unsuccessful call an X-ray engineer. holes either side of it) is directly over the center • Inform staff. of the bucky and tape it down. The central ray is • File a report. therefore centered to the middle of the middle hole of the test tool. Central ray centered to the middle of the • Note which side the three small identification bucky test holes are on. If the X-ray beam is not aligned correctly to the • Collimate to cover only the center holes. bucky the grid will create an uneven density • Cover all other holes with the lead rubber. image. • Make an exposure. • Do not move test tool. Frequency of test • Off center the tube so that it is centered over • Yearly. the next hole. • As necessary. • Adjust the lead rubber so that only this hole is uncovered. Equipment required • Leave all other parameters unchanged. • One 24 x 30 cm loaded cassette. • Make an exposure. • Test tool (see Fig 3-11 and Appendix A, page • Repeat the procedure for all five holes and the 137). identification holes, six exposures in all. • X-ray unit to be tested. • Process the film. QUALITY ASSURANCE WORKBOOK 70 Evaluation _maximum mA about 50 to 100. May have a pulsed • The density of the central hole should be the high output or capacitor discharge. Uses a 240 volt power est, the holes on either side a little lighter, but of supply. More sophisticated mobile units may be me the same density as each other. The two outer dium or high frequency and may have motor driven holes a little lighter again, but the same density movement. as each other. • The three small holes are simply to allow correct Moving the unit orientation of the image. • Mobile units which need to be pushed, have brakes which operate on the "dead man's handle" prin Action ciple. The breal< handle must be depressed to re • If the densities of the holes do not appear as lease the bral Mobile Electrical • HT cables for wear and abnormal bends. Mobile X-ray unit is defined as an X-ray unit on wheels, • Hand switch cable for wear, if fitted (modern capable of being moved from one location to another safety regulations do not recommend the use of with relative ease. It is bigger than the portable, has a hand switches on extension cables. higher output and is usually a little more sophisticated. • Power supply cable for wear and twisting. May or may not have a stationary anode tube. Has an • Plugs and connections. electronic timer. The maximum kV is about 90-100, MODULE 3. X-RAY EQUIPMENT 71 • Check collimator (see Module 2. Accessory equip- Cleaning ment, page 29). • Dust daily with a clean dry cloth. • All control panel display lights are working. • Dirt that resists a dry cloth should be wiped with • All switches are tight and working. a cloth very lightly dampened with water (do not • Meters working. use excessive water as this may get into the elec • Unit exposes when exposure button depressed. trical components and cause corrosion or Any faults must be fixed or reported immediately. shorting). QUALITY ASSURANCE WORKBOOK 72 Notes MODULE 3. X-RAY EQUIPMENT 73 TASK 11 Consistency of radiation output The density of your radiographs is not consistent, despite using proven exposure factors and techniques. a) Carry out an initial test that will demonstrate any inconsistency in radiation output. b) Evaluate your results. c) Answer the following questions, in the spaces provided. l. Record the exposure used. ______ 2. What is your evaluation of the resultant film? 3. Is this a satisfactory result? Yes/No 4. What action do you recommend? Include your test film with these answers. Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor QUALITY ASSURANCE WORKBOOK 74 TASK 12 Constancy of radiation output at di erent mA settings test You have carried out an initial test and proved that the radiation output is inconsistent. Carry out a test that will attempt to identify the problem. a) Carry out a test to investigate the consistency of mA settings. b) Evaluate your results. c) Answer the following questions, in the spaces provided. l. Record the exposure used. 2. What is your evaluation of the resultant film? 3. Is this a satisfactory result? Yes/No 4. What action do you recommend? Include your test film with these answers. Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor MODULE 3. X-RAY EQUIPMENT 75 TASK 13 X-ray timer test Your radiography densities are still inconsistent. You have already checked the mA and found it to be consistent. Carry out a further test to try and identify the problem. a) Carry out a test that will demonstrate inconsistency in the X-ray timer. b) Evaluate the results. c) Answer the questions below in the spaces provided. l. Record the frequency of the electrical mains power supply to the unit you used? 2. Indicate with a tick, which of the following describe the unit you used? • One pulse, self rectifies. ______ • Two [lUise, full-wave rectified.------ 3. Is the timer accurate? YES/NO 4. Explain how you arrived at your answer to question 3. 5. What action do you recommend? Include your film with these answers. Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor QUALITY ASSURANCE WORKBOOK 76 TASK 14 Mechanical and electrical check The routine mechanical and electrical checks are due on your X- ray unit. Carry out checks for function and safety. a) Carry out routine mechanical and electrical checks on an X-ray unit. b) Complete the following check list. Item to be checked Yes/No Comments Control panel Table Tube & ht cables Tube column & arm Other Action Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor MODULE 3. X-RAY EQUIPMENT 77 TASK IS Potter bucky Electrical & mechanical check The routine electrical and mechanical check is due on your bucky. Carry out checks for function and safety. a) Carry out routine electrical and mechanical checks on a bucky. b) Complete the following check list. Item Checked Comment Movement-Bucky on rails -Tray Locks -BUci -Tray Electrical -Cables -Plugs -Switches -Grid movement Other Recommended action Tutor's report Satisfactory/Unsatisfactory Signed Date Tutor QUALITY A:'S:!li~JL~ANC~ WORKBOOK 78 MODULE4 Manual film processing Aim ardous chemicals are used, under low light conditions (see Appendix B, page 156). To provide the knowledge and practical skills neces sary to effectively maintain a darkroom and manual The darkroom must: processing equipment, carry out manual film process • Be of suitable size. ing and establish and run a quality control program. • Must not allow white light to enter. • Have a suitable secure entrance. Objectives • Have appropriate safe lighting. • Have adequate white lighting. On completion of this module you will be able to • Have adequate ventilation. understand and carry out manual processing routines, • Have adequate drainage. quality control procedures, evaluate and recommend • Have a hot and cold running water supply. action for: • Have a convenient layout. • Have a flat smooth surfaced workbench of A darkroom adequate size and location. 11 Light proof. • Be in good condition. 11 Safe lights. • Be effectively and regularly cleaned. 11 Ventilation. • Have adequate storage space. 11 Storage. • Have a safe and reliable electrical supply. 11 Condition. • Maintain temperature and humidity at suitable levels. Film and chemical storage • Be radiation proof. 11 Stock rotation. • Be fitted out with film processing and accessory 11 Conditions. equipment. 11 Security. Other issues involving the darl The light-tight room in which, the processing of radio Responsibilities of staff using the darl White light leaking into darkroom • Cover half of the film with the sheet of card. • Leave for 3 minutes. Film should only be handled in correct safelight condi • Process the film. tions. White light should not be allowed to leak into the darkroom. Evaluation • If the density of the uncovered part of the film White light leakage test is greater than the covered part, then some Frequency of test fogging has occurred. • 6 monthly. • After work has been carried out on the darkroom. Action • As necessary. • Seal any areas of light leakage. • Repeat the white light leakage test. Equipment required • File a report • Insulation tape to temporarily cover holes. • Chalk to mark holes. Safe lights Method A darkroom should be fitted with appropriate safe light • Turn on all lights in areas adjacent to the ing. There are several different forms of safelighting darkroom. available. • Switch off all darkroom lights, including • Conventional safelight-smalllight tight box with safelights. a light filter window, fitted with bulb and socket. • Ensure that any doors are closed. • Simple bulb with filter coating. • Remain in the darkroom for 10 minutes to allow • Coloured fluorescent light tube. the eyes to get used to the dark. • Look around the darkroom for signs of white light Safelights should: leaks. • Be in good condition. • Pay particular attention to doors, windows, • Have the correct filters to suit the light sensitiv extractor fans, air vent and entry of pipes. ity of the film used. • Have the correct light bulb wattage, as recom Action mended by the manufacturer. • Identify then seal any white light leaks. • Be electrically safe. • Repeat the test. • Be installed correctly. • Carry out a test to see if any film fogging is occurring, if felt necessary. Check that: • File a report. • Each safelight is no less than 130 cm above the workbench. If you have difficulty in eliminating all white light, e.g. • The light bulb is correct (usually 15 watt if facing around doors, you may wish to try the following test. down). • The safelight filter is in good condition. White light fogging test • The safelight filter is compatible with the light Frequency of test sensitivity of the film being used (check with film • 6 monthly. manufacturer's information). • As necessary. • The safelight does not leak white light. • The wiring and fittings are in good condition. Equipment required • 1 sheet of new 18 x 24 cm film. Safelight efficiency test • 1 sheet of 18 x 24 cm card. Frequency of test • 6 or 12 monthly. Method • Turn on all lights in areas adjacent to darkroom. Equipment required • Switch off darkroom lights including safelights. • One 24 x 30cm cassette loaded with new film. • Ensure that any doors are closed. • Two sheets of 24 x 30 cm card. • Place the sheet of film on the workbench. QUALITY ASSURANCE WORKBOOK 80 • One timing clock or watch with second hand. - Exposed to safelight in 8 strips • One 24 x 30 cm sheet of lead or lead rubber. varying in length of exposure from 30 seconds to 4 minutes. Method • Identify the strip in Section B which has a • Place cassette face up on the X-ray table. noticeable increase in density compared to its e Set a FFD (SID) of lOO cm. equivalent strip in Section C. • Cover one third of the cassette with lead rubber, • Double check by comparing B with A. lengthways (area C). • Note the safelight exposure time of this • Collimate to the uncovered area of the cassette. strip. • Expose the film using a minimum exposure • This exposure time is the extreme limit of film (suggested exposure 45 kV 2 mAs). handling time. • Unload the cassette in the darkroom in total • 3 minutes is considered to be the limit of darkness. acceptable film· handling time. • Place the film on the workbench. • Cover one third of the exposed side of the film Action with the sheet of card, lengthways (area A). • If the identified safe handling time is considered • Cover areas Band C of the film, horizontally, with to be too short, consider one or more of the the second sheet of card, except for a 3 cm strip following modifications: at the top. - Increase safelight height above workbench. • Switch on the safelights. - Reduce wattage of bulb. • Start clock immediately. - Replace filter. • Wait 30 seconds. - Stop white light leak from safelight. • Move second sheet of card down 3 cm (the first - Remove one safelight, if more than one. sheet of card must remain in place throughout). • Re-test after modification. • Wait 30 seconds. • File a report. • Repeat this process every 30 seconds until the bottom of the film is reached. Ventilation • Switch off the safelights immediately. It is important for the darkroom to have adequate ven • Process the film. tilation. Ideally, a ducted air conditioning system with ·Note: Lightly pre-exposing the film makes it more light light tight vents. sensitive. A less efficient, but perfectly adequate system is an extractor fan, ducted to a safe area outside the dark room. The extractor fan should be sited near the A B C processing unit, with the air intake vent sited at the 1---1----1 4 m in 1------'1----1 3 m in 3 0 sec opposite end of the darkroom to ensure complete air 1------11----1 3 min circulation. The air exchange should be at the rate of Area not exposed 1------11-----1 2 m in 3 0 sec to safelights 15 changes an hour. ------1• 1-----lf----1 2 m in (control strip) 1---1----1 1 min 30 sec -_t=:::t::::j 1 min L 30 sec Storage Area exposed Cassette pass box radiation proof test to radiation If radiation fogging is suspected whilst cassettes are Fig 4-1. Diagram of the test film image in the pass box. Frequency of test Evaluation (see Fig 4-l) • Yearly. Section A - Sensitised by radiation. • As necessary. - Not exposed to safelights. Section B - Sensitised by radiation. - Exposed to safelights in 8 strips Equipment required varying in length of exposure from • 3 coins or lead markers. 30 seconds to 4 minutes. • Adhesive tape. Section C - Not sensitised by radiation. • lloaded 35 x 43cm cassette. MODULE 4. MANUAL FILM PROCESSING 81 Method Evaluation • Stick the 3 markers, at intervals, down the • Assess the degree of fogging on each film. long edge of the front of the cassette with the • Decide whether this fogging is acceptable or not. tape. • Place the cassette in the pass box, with the Action markers nearest to the X-ray room. • If fogging is acceptable or there is no fogging, • Leave the cassette there for a week. take no further action. • Process the film. • If fogging is unacceptable: - Use as "clean up" film for an automatic Evaluation processo~ or • If fogging has occurred to the extent that the - Discard, or markers can be seen, repeat the test over a - Remove fogged portion by cutting down to shorter period. smaller size. • Establish a period of time when fogging does not • Remind staff to be more careful. occur. • File a report. Action Static electricity • Do not store cassettes in the pass box. • Remove cassettes from the pass box within the Static electricity charges tend to build up, due to fric no fog period. tion. Low humidity and nylon clothing increase the risk • Increase lead shielding to pass box. of static build up. Most film manufacturers recommend • File a report an· ideal film handling humidity of 40% to 60%. Static build up on X-ray film is fairly common in dry areas. Note: Radiation fogging may be occurring in the X-ray Static discharge is seen in the dark as an instanta room. Carry out the above test in the cassette storage neous flash of bluish white light. If this discharge takes bin and other areas where cassettes are temporarily or place on the surface of an unprocessed film, it will be permanently stored. seen as areas of blackening, often "lightning like", on the processed film. If static marks appear on films it Accidental light fogging of film will be necessary to carry out remedial work. Occasionally staff may leave a film hopper open or the Action lid off a film box when a white light is switched on.This • Wipe over all film handling surfaces regularly with of course, will fog the films, but not necessarily to the an anti-static solution (intensifying screen cleaner extent that they are unusable. may be used as it contains an anti-static agenO. Due to the fact that films are closely packed, • Clean intensifying screens with a cleaner contain the light may not penetrate much below the top ing an anti-static agent. edge. • Instruct staff not to slide films into cassettes or across working surfaces. Degree of light fogging of films • Encourage staff not to wear nylon clothing. assessment test • Check humidity levels. If found to be low, install a Equipment required humidifier. • Pencil. • All film handling surfaces, film bins and pass boxes • Films to be tested. should be electrically grounded. Method Film and chemical storage • Under safelight conditions: - Remove the front film, rear film and one from Film storage the middle of each pack of film that is likely X-ray film should be stored according to manufac to be affected. turer's recommendations. - Identify which film is which, using pencil Unexposed film is sensitive to radiation, light, marks. temperature, humidity, chemical fumes, bending and - Process the films. pressure. It is important that unexposed film is stored QUALITY ASSURANCE WORKBOOK 82 correctly, both in the long term (main film store) and in • Clearly mark all film boxes with the date they the short term (darkroom). arrived in the store to ensure the rotation system All film is given an expiry date, beyond which the fog will work. level is likely to increase. This date can be found printed • Film boxes should only be stored one deep, to on the outside of the film box. Some film has been ensure easy access and correct operation of the known to age prematurely. Adequate stock rotation is rotation system. therefore important. • Film boxes should always be tal Film stock record Film size ______Manufacturer ______ Type of film ______ Boxes of lOO Films Date In Out Total Supplier Destination Signature Fig 4-2. Example of a film stock record sheet MODULE 4. MANUAL FILM PROCESSING 83 Short term storage • Room temperature should be between 10 oc and • Store only films for immediate use in the darkroom. 20°C. • If possible, store films in a specialised, lockable • Clearly mark chemical boxes with date of arrival. film hopper. • Use a rotation system, first in first out. • Preferably a hopper fitted with a micro switch • Take from the left, shelve on the right. that switches off the white light when opened. • Do not store too high, this may cause handling • Place a warning label on the front of the hopper problems or injury. stating "DO NOT OPEN IN WHITE LIGHT". • Keep strict stock records (see Fig 4-3). • Store films by size. • Check regularly for any chemical leaks. • Standardise the film size location in the hopper. • Clean up any leaks immediately. • Do not overfill the hopper. • Any windows must have blinds or shutters. • If no hopper is available, store in original boxes, • Keep daily records of temperatures. conveniently located. • Keep store locked. Allow access only to author ised personnel. Care must be taken to ensure that film box lids are always replaced or hopper closed, before switching on Short term storage the white light or opening the door. • Only keep a small stock of chemicals in the Care must be taken not to damage film boxes. darkroom. • Store away from working area. Chemical storage • Check regularly for leaks. X-ray processing chemicals should be stored accord • Clean up spills or leaks immediately. ing to manufacturers recommendations, preferably away from stored films. Film processing There are several types of film processing units: Long term storage • Store in a well ventilated room. • Manual. • Store away from the film store. If this is not • Bench top automatic. possible then chemicals must be kept at least 4 • Full size automatic-varying degrees of metres away from stored film. sophistication. Chemicals stock record Devel oper/fixer Manufacturer ______ (Cross out the one not applicable) Supplier ______ Type Date In Out Total l Supplier Destination Signature I i Fig 4-3. Example of a chemical stock record QUALITY ASSURANCE WORKBOOK 84 Whichever type of unit is used, a regular quality con • Adequate ventilation (15 air changes per hour is trol program should be followed in order to continually recommended). produce high quality radiographs. • Vent exhaust ducts to an appropriate outside area. • Check that airflow in the darkroom does remove Safety precautions in (1/m processing (see Health all fumes adequately. and safety, page 15) • Faults and problems should be reported or Exposure to processing chemicals and their fumes can remedied immediately. be harmful • Safely dispose of exhausted chemistry. • Processing chemicals should not come into • Safely dispose of contaminated water. contact with the skin or eyes. • Safely dispose of empty chemical containers • Processing chemicals should not be swallowed. (do not allow others to use as drinking water • Processing chemical fumes should not be containers). inhaled. • Safely dispose of unwanted film. Notes: Remember that film, film processing chemicals Wear protective clothing when mixing chemicals: and their containers are hazardous and must not be • Waterproof apron. disposed of in any way that may pollute the environ • Rubber gloves. ment or cause sickness or injury. • Goggles. Silver can be reclaimed from exhausted fixer • Face mask. and film. You may be able to sell this to a recognised dealer. First aid If chemicals come in contact with the sl Overflow Standpipe L / 0 .. 0 D w F D R F w (a) (b) D = Developer F = Fixer R = Rinse W = Wash Fig 4-4. Diagrams of the layouts of two different manual processing units MODULE 4. MANUAL FILM PROCESSING 85 Equipment • Wash all tanks thoroughly and scrub until • Deep tank - Develope~ fixe~ rinse and clean. processing unit wash tanks with lids • Use different brush/scouring pad for developer Thermostat. Suitably and fixer. plumbed. • Flush drainage pipes and ensure they allow free • Film hangers - Tension type to fit all film flow. sizes. Suitable hanging • Replace overflow stand pipes. brackets for hanger • Close all other tank outlets. storage. • Scrub inside of film hanger clips. • Drying cabinet - With variable heating control and timer. Mixing chemicals or • Check that tank sizes are standard and that the • Drying racks - Suspended or wall fixture. manufacturer's quantities are correct for your • Thermometer - Alcohol or electronic. tanks. • Hydrometer - Scale range SG 1.075 to • Mix according to manufacturer's instructions. 1.115. • Follow manufacturer's safety precautions. • pH paper - Litmus paper. • Use different stirring rods/paddles for developer • Silver - Specialised rolls may be and fixer. estimating available from the film • Wear protective clothing. paper manufacturer. • Check that room ventilation is adequate. • Thiosulphate - Bottle of specialised test • Minimise splashing. retention test fluid. • Ensure that fixer does not contaminate developer. fluid • Clean up any spills immediately. • Timer - Specialised photographic timers are preferred as Water supply they are more versatile and • Should have hot and cold running water reliable. available. - Mechanical kitchen timers • Should be reliable. are not recommended. • Must be clean. Timer accuracy should be • Do not mix chemistry with water that has a checked regularly. very high chlorine content. This may cause the • Chemical - 2 PVC or stainless steel active fixing agent (sodium thiosulphate) to drop stirrin~ rods rods or paddles. One out of suspension, reducing the action of the labelled "devel oper" the fixer. other "fixer". There must be no cross use. Refilling water tanks • Measuring - lOOml, graduated, glass or • Refill to top of stand pipes. cylinder plastic. • Regulate flow. • Protective - Waterproof apron, rubber • The wash tank water should flow at the rate of clothing gloves, goggles, face mask. four exchanges an hour. • Cleaning - Clean disposable cloths. materials Clean hand towels. Rate of water flow test Tank cleaning brushes. • Time how long it takes for the tank to fill with Scouring pads (plastic water once. This should be approximately 15 min type). utes, to make four changes in one hour. • Adjust water flow accordingly. Cleaning • If too slow, and the tap is fully open, there may • Switch off any heating or cooling devices in the be a partial blockage, or this may simply be due unit. to normally low water pressure. • Drain developer, fixer and water tanks. • Fixer may be retained for silver recovery. Heating I cooling units • Ensure that chemistry and contaminated water • Switch on. is disposed of in a safe manner. • Ensure they are working. QUALITY ASSURANCE WORKBOOK 86 Clean up the time/temperature graph is not available it will be • Wipe over all exposed sutfaces. necessary to carry out a test to determine the correct • Wash and store accessory equipment. development temperature. • Safely dispose of all empty chemical bottles and cartons (puncture and place in a sealed plastic Frequency bag before disposal). • As required. • Wipe down aprons, gloves and goggles. • Replace any tank lids. Equipment required • Six sensitometry test strips (see Module 5. Before using the unit Automatic processing, page 107). • Wait for processing temperature to reach the • Thermometer (not mercury). required level. This may take several hours. • Six film clips or safety pins. • Check temperature. • Developer stirring rod. • Check water flow rate. • Timing clock. • Check chemical levels. • Densitometer. Developer Method This test can only provide a development time for one The chemical treatment that converts the latent film temperature level. If a range of temperatures prevail image into a visual image. then this test must be repeated for each temperature required. Developer temperature and • First, regularly check the developer temperature. development time • Determine the prevailing temperature. Development time and temperature directly affect • Before commencing the test, stir the developer the density, contrast and amount of base fog of a and check the temperature. radiograph. • In safelight conditions number the test strips in • Follow manufacturer's time/temperature pencil, 1 to 6. recommendations. • Attach the test strips to the film clips Cor safety • Use manufacturer's time/temperature adjustment pins) and suspend in the developer. All strips must graph when necessary (see Fig 4-5). enter the developer at the same time. • Start the time clock immediately. Determining the best development time • After 30 seconds remove test strip 1, rinse and If local conditions make it difficult to use the manu place in fixer. facturer's recommended development temperature and • After a further 30 seconds Cone minute of devel opment) remove test strip 2, rinse and place in fixer. 24 • Repeat this process every 30 seconds until all test strips are in the fixer. 23 • Fix, wash and dry test strips. 22 Evaluation 21 • Arrange strips on a viewing box, side by side, in Temperature ac 20 numerical order, with all unexposed steps at the same end Csee Fig 4-6). · 19 • Study the unexposed steps. 18 • Identify the strips that do not show any base + fog level increase. 17 • Study the middle density steps and identify the 16 strips which do not show a density level increase. 01234567 • The most suitable development time, at the tem Development Time (minutes) perature used, is the time that gives maximum Fig 4-5. Time/Temperature Development density but shows no increase in base fog. Graph MODULE 4. MANUAL FILM PROCESSING 87 :~ • Constantly monitor developer temperature. ••.l/2 min dev Strip l • Remove bag when temperature falls to a satisfactory level. • Great care should be taken to avoid bursting the bag in the developer. Under no circumstances add ice directly to the ll/2 min dev Strip 3 developer. 2. • Use a coil of copper tubing, large enough to just fit into the developer tank. • Fit a hose to one end of the copper tubing, long enough to reach from the tap to the 2 l/2 min dev Strip 5 developer tank. Fit hose to tap. • Fit a hose to the other end of the copper tub ing; long enough to reach from the developer 3 MIN DEV STRIP 6 tank to a drain or sink. Fig 4-6. Development time assessment strips • Submerge copper coil in the developer. arranged for comparison • Turn on cold water. • Constantly monitor developer temperature. • Remove coil when temperature falls to a • A densitometer may be used to determine satisfactory level. density levels if available. • Turn off water. • If a range of temperatures need to be investi gated to determine the best development time To increase developer temperature for each, the test is repeated for each tempera • The two methods described above can be used. ture and the result charted or a graph produced. Replace ice and cold water with hot water. • Electric immersion heaters can also be use. Action • Establish a time/temperature chart (see Fig 4-7). Developer activity The activity of the developer affects the density, Emergency measures contrast and amount of base fog of a radiograph. To reduce developer temperature It is important, therefore, to regularly check devel l. • Fill a strong plastic bag with ice. oper activity. Developer activity tests should be carried • Firmly tie off the neck of the bag with cord. out immediately after the developer has been renewed • Submerge the bag of ice in the developer or and at least once a week. water jacket if there is one. Some departments do them daily or even twice daily • Agitate. when mammography is involved. Temperature/development time chart Temperature of developer oc Development time ! I I. Fig 4-7.Time/temperature chart used for recording data when assessing development time QUALITY ASSURANCE WORKBOOK 88 Developer activity test (Elementary method) One step difference =acceptable (see Module 5. Automatic processing, page 107, for a Two steps difference =acceptable but be warned more accurate method). Three steps difference =unacceptable take action • If the test strip is moved up, compared to the Frequency of test control strip, the result is regarded as positive. • Daily. • If the test strip is moved down, compared to the control strip, the result is regarded as negative. Equipment required • Graph the results (see Fig 4-8). • One sensitometric strip (see Module 5.Automatic processing, page 107). Action • Sensitometric strips from previous tests. l. If densities are lower than previously: • Graph paper. • Developer - Exhausted. may be - Incorrectly mixed-too Method much water. • Stir developer. - Water added instead of • Check temperature of developer. replenisher. • Adjust temperature to pre-determined standard 2. If densities are higher than previously: if necessary. • Developer - Too active because of • When temperature is correct, develop the test may be incorrect mixing. strip. - Too much replenishment. • Mark the strip with the date. 3. Higher basic fog level than previously: • Chemical contamination. Evaluation • Compare the test strip with the control strip (see Developer activity using a hydrometer test Fig 4-9). • An hydrometer will measure the specific gravity • The equivalent steps should have the same den (SG) of developer. sity. This confirms consistent developer activity. • Specific gravity measures the relative weight of a • If the strips are not comparable, adjust them until solution, when compared to water, at 23 °C. they are. • Specific Gravity measurement can therefore be • If adjustment has been necessary, count the used to show if correct dilution is present. number of steps difference between the two • The specific gravity (or density) of water is strips. 1.000. 3 Positive 2 l Steps 1 2 3 4 56 7 8 910 1112 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 l DATES 2 Negative 3 Fig 4-8. Developer activity graph chart New strip Old strip Fig 4-9. Developer activity test strips. Comparison of old against new MODULE 4. MANUAL FILM PROCESSING 89 1.088 1.087 1.086 1.085 Specific 1_084 Gravity 1.083 1.082 1.080 1.079 '------14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Temperature oc Fig 4-1 0. Specific gravity/temperature graph • The specific gravity of developer falls into a range Equipment required of 1.070 to 1.100. • pH paper (litmus paper). • Specific gravity will vary with developer tempera ture (see Fig 4-10). Method • Hold a strip of test paper in the developer for Frequency of test approximately 10 seconds. • Daily. • Observe colour change. • Compare with control strip. Equipment required • Hydrometer Can hydrometer designed for testing Evaluation car batteries can be used, but the scale will need • Note manufacturer's recommended pH range to be extended). (usually around 10.0 to 10.5). • Manufacturer's recommended specific gravity for • Compare test strip reading to recommended the developer being tested. range. • A reading of more than 0.4 below manufactur Method er's recommendations suggests contamination. • Place the hydrometer in the developer. It will float. • A reading of 0.8 below suggests oxidation. • Note the reading on the scale at the level of the developer surface. Action • Replace developer if readings are too high or too Evaluation low. • The Specific Gravity reading should be within plus or minus 0.004 of the manufacturer's Developer replenisher recommendations. • If the reading is lower than that recommended, Replenisher is the chemistry added to the developer to the developer is over diluted. maintain its volume and activity. • If the reading is higher than that recommended, • Replenisher is generally more active than the the developer is too concentrated. original developer. • Mix according to manufacturers instructions. Action • Have a quantity of replenisher mixed and stored • If too concentrated add water. in the darkroom for convenient use. • If too dilute add replenisher or replace the • Add replenisher when developer level falls. developer. • Do not allow level of developer to fall below the top of films. Developer activity using pH paper (litmus paper) test Can be used for freshly mixed develope~ but is more Rinse useful to show contamination or oxidation. The process of using clean water to wash residual developer from the film, so avoiding contamination Frequency of test and reduction in efficiency of the fixer. • Daily. QUALITY ASSURANCE WORKBOOK 90 • Separate rinse water tanks between developer • A high specific gravity reading-not dilute and fixer should have running water. enough. • Static rinses should have the water changed • A low specific gravity reading-too dilute. · regularly. • Agitate films vertically in static rinses. Action • Rinse for 15 seconds. • Dilute if specific gravity reading too high. • Add undiluted fixer if specific gravity too low. Fixer Silver estimation test Dissolves off all unwanted film emulsion. Indicates level of silver concentration in fixer solution. Makes image permanent. Fixing temperature and fixing time, although impor Frequency of test tant, are not as critical as those of the developer. • Daily. Clearing time Equipment required • The time it takes to clear the film (dissolving off • Silver estimation paper. the unwanted film emulsion). • Can take from 30 seconds, but should not be more Method than 2 minutes. • Place paper in fixer. • The film may be viewed in white light once it has • Compare with control. fully cleared. • Take reading. Permanent fixing Evaluation • This is usually twice the length of the clearing • Below 2 gm/1 is over replenished. time. • Above 6gm/l is under replenishment. • It is recommended that all films be fixed for at least 4 minutes to avoid image deterioration later. Note: Freshly mixed fixer will have a zero reading. • Remove films from the fixer as soon as adequately Action fixed, as excessive time in the fixer will remove the image. • Below 2 gm/1 add water. • Above 6gm/l add undiluted fixer. Fixer activity using a hydrometer test Specific gravity of the fixer is an indication of its activ Wash ity (see Developer activity test, pagej_ BBljThe specific The use of clean water to wash all residual fixer from gravity of fixer should be in the region of 0.004 (see the film, so avoiding the deterioration of the image manufacturer's recommendations). over time. Frequency of test • Wash films for 20 minutes in running water, at • Daily. a rate of four exchanges an hour, in order to ensure satisfactory long term storage of Equipment required rad i og rap hs. • Hydrometer. • Should there be a need to conserve water, then slower flow rates and shorter wash times can be Method used, but it must be remembered that the wash • Place the hydrometer in the fixer. ing process will be less efficient and radiographs • Note the reading at the surface of the fixer. will deteriorate quicker during storage. Consid eration should be given to manual vertical agita Evaluation tion when water flow is slower, or wash times • Specific gravity reading should be within shorter, than recommended, in order to improve plus or minus 0.004 of manufacturer's the washing efficiency. recommendations. • Where there are no facilities for a running water • Specific gravity should be in the region of 1.110. wash, it is recommended that radiographs remain MODULE 4. MANUAL FILM PROCESSING 91 in the water tank for 2 hours, then given 30 Unprocessed film handling seconds of manual, vertical agitation. Correct film handling will avoid film damage. Water level must be above top of film hangers to • Handle only under correct safelight conditions, ensure hangers are completely washed. to avoid fogging. • Handling time should be kept to less than Hypo retention test 3 minutes/ to avoid fogging. This test indicates the amount of residual thiosulphate • Keep hands dry when handling films1 to avoid remaining in the film emulsion, after film processing marking the film. has been completed. An indication of adequate/inad • Hold film only on the edges, with tips of fingers1 equate washing. to avoid marking the film. An excessive amount of residual thiosulphate in a • Do not allow film to bend (bending affects the film emulsion may cause a brown stain to appear on film emulsion producing artefacts). the film. • Do not allow film to slide over any surface (this may create static marks). Frequency of test • Do not allow film to come into contact with any • Weekly. moisture1 before entering the developer (water • As necessary. or developer will cause premature development and create dark areas, fixer will stop the devel Equipment required opment process and create clear areas). • ljypo (thiosulphate) retention test fluid. • Tension film correctly in hanger. • Test strip. • Always handle the film with care. • Radiographs to be tested. Labelling film Method • Put a drop of test fluid on the surface of the film All films must carry the patient's name1 date X-ray well clear of the image. examination carried out and any other information • Wait for one or two minutes. considered necessary, to allow correct and easy identification of the radiographs. Evaluation • Inspect the moistened area. Methods of labelling films • Compare colour with test strip. • Print directly onto the film with a written or typed ticket and a light source1 under safelight condi Action tions in the darkroom. • If colour indicates a high level of thiosulphate, • Print directly onto the film with written or typed check wash water flow and washing time. ticket and a light source while the film is still in • Adjust and re test. the cassette. This system can be used under white light conditions (special cassettes and printer are required). Drying • Write on the film in pencil, under safelight condi To remove all moisture, harden the image and make tions, before processing, and then stick a written the radiograph durable. or typed label onto the film after processing. Writ ing on the film in white ink after processing is • Drying cabinet or air drying. also acceptable. • Ensure that films are fully dried before removing • Directly onto the film using radiation. Write or from the hangers. type on a specially prepared radio-opaque slip. • For emergency drying, a hair drier on warm can This slip is placed on the face of the cassette be used: 1 within the radiation field prior to exposure. - Hold film vertical. 1 - Sweep warm air horizontally across surface The preferred method is to have the patient identify of film, working from top to bottom. ing information in the film emulsion and not written - Do both sides. on after processing. The most commonly used is the - Do not get nozzle of drier too close to film. first method given above. QUALITY ASSURANCE WORKBOOK 92 The printer • Is the density control knob tight? • Study the resultant test film. An easy and accurate method of radiograph • Do the printed areas get progressively darker in identification. the right order Cl to 4)? There are two main types of printer, both using a • Which of the printed areas is the most light source and requiring electricity to power them. satisfactory? • Darkroom printer for use under safelight condi • Is the clarity of this image acceptable? tions only. • Is this the setting that is routinely used? • The printer used under white light conditions, requiring special cassettes. Action • If th~ printer is unsafe or is not working efficiently Darkroom printer check arrange for repair. Frequency of checl< • Select the image that best demonstrates the • 6 monthly. typed/written information. • As necessary. • If this is the setting routinely used take no action. Equipment required • If the selected setting is different from that rou • Printing ticket of the type that is routinely used. tinely used, inform staff of the new setting. • One sheet of 18 x 24cm unexposed film. • If the writing/ typing is not clearly seen in any of • Printer to be checked. the images, carry out the test again using a dif ferent thickness of ticket and/or looking for ticket Method movement when printing, until a satisfactory • Inspect electrical cable and plug. result is obtained. • Check that the light comes on when activated. • File a report. • Check light intensity control is not loose. • Check that the light is not obstructed. Processing routine • Using a pencil, mark the maximum, minimum and two evenly spaced intermediate settings of the The method by which films are processed in order to light intensity control, around the control knob. produce high quality images. Label these marks 1 to 4 starting with the light est setting. Method • Write or type a printing ticket and insert it into • Stir solutions. the printer using the recommended practice. • Take the developer temperature. Read while • Set the light density control to setting 1 (mini thermometer is still in developer. mum intensity). • Check correct development time at this tempera • Under safelight conditions, use a pencil to write ture. Refer to manufacturer's time/temperature identifying numbers 1 to 4 in the respective cor graph or your own time/temperature chart (see ners of the film. page 87). • Insert the corner of the film marked l into the • In safelight conditions load film into hanger. printer, ensuring that it goes in correctly. • Keep fingers to edge of film only. • Activate the light in the printer. • Ensure correct tension of film in hanger. • Remove the film and insert the corner marked 2. • Set timer for correct developing time. • Re set the light intensity control to setting 2. • Lower hanger and film into developer. • Activate the light in the printer. • Hold hanger so that fingers do not come into • Repeat this procedure using setting 3 for corner contact with developer. 3 and setting 4 for corner 4. • Agitate film in vertical direction two or three times • Process the film. to remove air bubbles and distribute developer evenly over the film. Evaluation • Place hanger in developer so that film is fully • Electrical cable wear or damage? immersed. • Plug damage or unsafe electrical connections? • Agitate film every 30 seconds during development. • Is anything obstructing the light? • When timer alarm sounds, lift film from the • Does the light work? developer and drain into the rinse (exhausted MODULE 4. MANUAL FILM PROCESSING 93 developer should not be drained back into the • Leave in running water for 20 minutes. developer). • Lift film from wash and allow to drain back into • Lower film into rinse for 15 seconds (agitate if the wash tank. This will minimise amount of rinse is static). water being transferred to drying area. • Lift films from rinse and allow to drain back into • Place film in drying cabinet or on an air drying the rinse (rinse water should not be drained into rack. the fixer as this will result in dilution of the fixer). • Do not remove until fully dry. • Lower film into the fixer. • Agitate two or three times. Notes • Ensure that film is fully covered by fixer. • All film movement in the chemicals or water must • The film may be viewed in white light conditions be carried out in a vertical direction or the film once it has cleared. may come off the hanger. • Leave film in fixer for at least 4 minutes to fully • When moving or draining films, always tilt away fix. from you, to avoid chemicals or water draining • Lift film from fixer and transfer directly to wash back toward you. (exhausted fixer from the film should not be allowed to drain back into the fixer tank). QUALITY ASSURANCE WORKBOOK 94 Notes MODULE 4. MANUAL FILM PROCESSING 95 TASK 16 Assess a darkroom for white light leaks An increasing number of radiographs have a grey fog. Equipment, radiation safety measures and processing have all been checked and found to be satisfactory. Check to see if the problem lies with the darkroom itself. a) Select a darkroom. b) Carry out the white light leak test. c) Answer the following questions in the spaces provided below. l. Were there any white light leaks? YES/NO 2. Briefly describe where you saw light: ______ 3. Are these white light leaks likely to be a problem? ______ 4. What is your recommended action?------ Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor QUALITY ASSURANCE WORKBOOK 96 TASK 17 Are films being fogged by white light leaking into a darkroomt You have noticed white light leaking into your darkroom around the door. It will be difficult to fix it. Check to see if this light is likely to fog films. a) Select a darkroom. b) Carry out the test to see if white light leaks are fogging films. c) Evaluate the film. d) Answer the following questions in the spaces provided below. l. Outline the procedure you carried out: ______ 2. Give your evaluation of the film: ______ 3. What action do you recommend based on your evaluation of the film: ______ Include your films with these answers Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor MODULE 4. MANUAL FILM PROCESSING 97 TASK 18 Safelight evaluation Film is being slightly fogged. You have checked the darkroom for white light leaks 1 the cassettes are in good condition and it isn't radiation fog. You suspect the safelight. a) Carry out a safelight evaluation test. b) Evaluate your results. c) Answer the following questions in the spaces provided below. l. How many safelights are there?------2. What colour are the safelight filters?------3. What is the colour sensitivity of the films used? ______4. Is the safelight filter colour the correct one? ______ 5. What condition are the filters in?------6. What is the wattage of the light bulb in the safelights? ______7. Is this the correct wattage? YES/NO 8. What is the distance between the safelights and the workbench top? ______9. Is this distance acceptable? YES/NO 10. If the distance is not acceptable1 why not? ______11. Are there any white light leaks from the safelights? ------12. What is your evaluation of the test film? ______ 13. Based on your answers1 what action do you recommend? Include your test films with these answers. QUALITY ASSURANCE WORKBOOK 98 Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor MODULE 4. MANUAL FILM PROCESSING 99 TASK 19 Film and chemical stores You are concerned about the conditions under which your films and processing chemicals are stored. a) Assess the long term storage of films and chemicals. b) Answer the following questions in the spaces provided. l. Are films and chemicals stored separately? YES/NO 2. Are the locations of these stores satisfactory? YES/NO 3. Ifnot,whynot? ______ 4. How are the films stored? ------ 5. Is this satisfactory? YES/NO 6. Ifnot,whynot? ______ 7. How is satisfactory stock rotation achieved? Films:------ Chemicals: ------ 8. What is the temperature inside the Film Store?------9. Is this temperature satisfactory? YES/NO 10. Ifnot,whynot? ______QUALITY ASSURANCE WORKBOOK 100 ll. Are the film and chemical stores kept locked? YES/NO 12. What records are kept regarding stock movement?------ 13. Based on your evaluation of the film and chemical stores, what recommendations would you make? Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor MODULE 4. MANUAL FILM PROCESSING 101 TASK 20 Safety in film processing You have just been appointed safety officer for your department. You need to find out if the darkroom is a safe working environment. a) Select a darkroom. b) Make a check list and investigate the points on it. c) Make brief comments on your findings alongside each point on your list. d) In each case write in your recommended actions. Write your findings below. If there is insufficient space, use additional sheets of paper and attach. QUALITY ASSURANCE WORKBOOK 102 Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor MODULE 4. MANUAL FILM PROCESSING 103 TASK 21 Checking manual development time Radiographic density is inconsistent, you have fully tested your X-ray unit, the chemistry is freshly mixed and the developer thermostat is working effectively. You suspect that the development time is not appropriate for the prevailing conditions. a) Select a manual darkroom. b) Carry out a manual development time check. c) Answer the following questions in the spaces provided. l. What is the commonly used development time?------ 2. How is this time arrived at?------ 3. What is the developer temperature after stirring? ______ 4. What is your recommended development time after evaluating the test strips? 5. How does this temperature compare to the established practice for this darkroom? 6. What is your recommendation for action? ______ Include your test films with these answers. Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor QUALITY ASSURANCE WORKBOOK 104 TASK22 Assess developer activity Radiographs consistently look light and lacking in detail. You have checked development time and temperature. a) Carry out a developer activity check. b) Carry out the same test 2 days later with the same processing unit. c) Answer the following questions in the paces provided. l. Developer temperature at first test:------ 2. Developer temperature at second test: ______ 3. What is your evaluation of the test strips?------ 4. What are your conclusions?------ 5. What are your recommendations for action?------ Include your test films with these answers. Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor MODULE 4. MANUAL FILM PROCESSING 105 TASK 23 Manual film processing Radiographic quality has fallen. It is NOT related to positioning, exposures or X-ray equipment. Someone has suggested that you are getting lazy with your manual processing. Check out your processing routine. Answer the following questions in the spaces provided. l. What was the development time?------ 2. How did you select the development time? 3. What was the film clearing time?------ 4. What was the full fixing time?------ 5. Why should the film be drained into the rinse after development? ______ 6. Why should the film be drained into the rinse after rinsing? ______ 7. Why should the film be drained into the wash after fixing? ______ 8. Why agitate the film?------ 9. Why agitate the film vertically?------QUALITY ASSURANCE WORKBOOK 106 Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor 107 MODULE 5 Automatic film processing Aim Choosing an automatic processor Identify your needs To provide the knowledge and practical skills neces • Throughput of films. sary to use an automatic processor correctly and es • Complexity of unit. tablish an effective, regular maintenance and quality control program. To provide an insight into choosing Resources available and accepting a new automatic processor. • Power. • Water. Objectives • Space. On completion of this module you will: • Exhaust systems and ventilation. • Maintenance and repairs. &I Have an understanding of the function of auto • Finance. matic processors. il Have the knowledge and skills to carry out Manufacturer warranty basic maintenance checks on automatic • Warranty period. processors. • Warranty cover. il Have the knowledge and skills to set up a quality • Determine responsibilities. control program for automatic processing. il Have the knowledge and skills to carry out Supplier service specific quality control tests on automatic • Installation. processors. • Initial QC tests. Ill Have the knowledge to be able to evaluate the • Maintenance. quality control results and recommend remedial • Repairs. action. • Parts. • Have an understanding of how to choose a new • Chemistry. automatic processor and the acceptance proce • Speed of response. dures following installation. Making the choice • Establish your processor specification Automatic film processing follows the same basic prin requirements. ciples as those of manual processing, but under auto • Do you want a silver recovery unit? mated and controlled conditions. The automatic • Review the manufacturer's specifications. processor and its chemistry must be maintained at a • Make a short list of suitable processors. high level of efficiency. Regular quality control moni • Submit your requirements to the selected manu- toring and maintenance is essential to ensure that high facturers for quotations. quality images can be produced consistently. • Review quotations. There is a range of automatic processors available, • Make your selection. from the small, simple bench top to the deep tank, more complex, models. The principles and methods Acceptance of new processor used to monitor processor performance are the same regardless of the type of automatic processor Upon completion of the installation and before accept used. ing responsibility for the new processo~you must check that: QUALITY ASSURANCE WORKBOOK 108 • Specifications of the processor installed are the • Film drying is carried out by, variable tempera same as that ordered. ture, hot air blowers. • Installation has been carried out as stated in the contract. Use of an automatic processor • Installation is complete and equipment is work ing efficiently and to your satisfaction. • Follow manufacturer's instructions. • All QC tests have been carried out and are • Place the film on the feed tray. satisfactory. • Ensure that the longer edge of the film leads and • All accessory equipment has been supplied and the shorter edge is in contact with the side of is in good order. the feed tray (smaller films may not mal Cleanliness (lack of) • When the processor has reached normal operat • Marked films. ing conditions carry out routine sensitometry • Contamination of chemistry. procedures (see Sensitometry1 page 112). • Build up of chemical deposit resulting in mechani cal failure. Normal working • Health hazard. • Follow operating instructions. • Constantly be aware of any abnormal noises1 changes in operation leaks or deterioration of Processor maintenance schedule 1 processed films. A processor maintenance schedule should be followed • Do not pull processed films out before they are regularly in order to detect or forestall faults. Read the clear of the rollers. maintenance and cleaning section of the operator's • Do not allow anyone to stand next to or lean manual. Closely follow the manufacturer's recom against the processor. mendations. Remember that cleanliness is vitally important. Shut down • Remove processor lid. Remember it will be nec Following are suggested schedules you essary to reactivate microswitches when lid is may find useful removed (see manufacturer's instructions). • Observe level of solutions. DAILY • Listen for abnormal noise or vibration. Before start up: • Observe transport system. • Remove crossovers and wash in warm water; with • Look for any leaks. a sponge or plastic cleaning pad (always do de • Switch processor off. veloper first, then fixer, to avoid contamination • Remove and wash all crossovers1 splash guards of developer). and tank lids. • Wash tank covers and splash guards. • Wipe over all deep rack rollers above solution • Wipe over all deep rack rollers that are above levels. solution levels. • Inspect and wash roller-drive cogs and drive • Clean all interior exposed surfaces. mechanisms. • Replace tank lids. • Check replenishment tanks/bottles levels1 color and smell. • Turn off wash water if appropriate. • Check replenishment hoses for bends or leaks. • Remove water dt·ain stand pipe if appropriate. • Replace water drain stand pipe if appropriate. • Wash off all chemical splashes on interior exposed • Turn on water and check that the tank is filling surfaces. (time flow if felt necessary). • Wipe any splashes from exterior surfaces. • Replace crossovers and tank lids. • Repiace processor lid1 leaving it slightly raised at one end to avoid build up of fumes and Start up condensation. • Switch processor on (you will need to activate • Door of darkroom should be left open with venti microswitches manually with the lid offl. lation system operating1 if power supply con • Listen for any abnormal noise or vibration. straints allow. • Check film transport system. • Place crossovers on top of processor/ with wash • Check replenishment system is working. stand pipe if appropriate/ and cover with a cloth1 • Replace processor lid. or store in a convenient cupboard. • Feed in one unprocessed 35 x 43 cm film (do not • Re stock1 chemicals1 films and any other depleted use processed film as these are harder and con supplies. tain fixer). • Recot·d ali restocking. • Inspect processed "clean up film". Feed in a • Report all faults. second film if felt necessary. WEEKLY • Clean exterior surfaces1 including the feed tray and receiving bin. Pay particular attention to the • Follow manufacturer's recommendations. feed tray. • Check solution temperatures, in particular the • Wipe over all darkroom work surfaces. developer (see Temperature check, page 110). QUALITY ASSURANCE WORKBOOK 110 - Compare with any readout on unit and • Record costs. manufacturers recommendations. • Continually review procedures, repairs, costs and - Adjust if necessary. quality of radiographs. • Check replenishment rates (see Replenishment rate check, page llD. By maintaining and using your processor correctly there - Adjust if necessary. will be: • Remove and wash all deep rack rollers in warm • less down time. water. • less inconvenience. - Inspect for correct function, wear or • lower costs. damage. • greater through put. - Rinse and re install. • greater efficiency. • Check main drive shaft and drive chains. • greater job satisfaction. • Carry out any other maintenance recommended by the manufacturer. It is up to you! • Report all faults. Electrical/mechanical systems check MONTHLY Frequency of checl< • Follow manufacturer's recommendations. • Daily. • Inspect all racks and component parts, during • Yearly by service engineer. cleaning. • Clean filters. Items to be checl • Read while in developer. • Place the end of the developer replenishment hose • Compare thermometer reading with the built-in in the graduated cylinder. readout temperature. • Feed a film into the processor. • A pre-set amount of developer will automatically Evaluation be pumped into the cylinder. Record this amount. • Compare test temperature with: • Empty cylinder and repeat for fixer. - Manufacturer's recommended temperature. - Built-in temperature. Evaluation • Record daily temperatures for comparison. • Compare amount of developer and fixer in cylin • Graphs may be plotted to show variations over der with manufacturer's recommendations. time (see Sensitometry, page 112). • look for variations of temperature: Action -Too high. • If amounts do not compare with recommenda -Too low. tions, adjust quantity regulator accordingly (see - Irregular. manufacturer's instructions). • Re-check. Action • File a report. • Regular variations of more than one or two degrees should be investigated. Cleaning • Check for likely cause: - Heater. Adequate cleaning avoids the risk of film contamina - Thermostat. tion, chemical build up on working parts and improves - Tests done at different times of the day. general health and safety. - Developer temperature not reaching operat- ing level after start up. DAILY • If necessary, call the processor service technician. At start up • Feed a 35 x 43 cm waste unprocessed film into Replenishment of developer and fixer the processoG to clean any deposits from rollers. It may be necessary to feed in a second film if Similarly to manual replenishment, automatic replen you feel it is necessary. Do not use processed film ishment maintains the level and activity of the process as this will be too hard and may contain residual ing chemistry. Pumps automatically replenish developer fixer. and fixer tanks each time a film enters the processor. • Do not proceed with the daily workload until you The replenishment rate is pre-set but can be varied are satisfied the rollers are clean. within manufacturer's recommendation. It should be based on the area of film passing through the At shut down processor. • Remove and clean all crossover rollers or plates. • Wipe off all chemical deposits on or around the Replenishment rate test processor. Take special care with film feed tray. Frequency of test • Drain the wash tank. • Monthly. WEEKLY Equipment required • Remove, clean and replace developeG fixer and • One graduated lOOml cylinder. wash roller racks. Method MONTHLY • Check that replenishment hoses do not have any • Drain the system completely, including bends that may restrict the flow. recirculation hoses and rinse with water. • Switch on the processor. • Charge the system with a dilute concentration of • Remove lid of processor. hypochlorite bleach (e.g. a 0.5% hypochlorite • Place activate micro switches, if present, to en solution). Take note of precautionary information sure that processor will function with the lid off. on hypochlorite container. QUALITY ASSURANCE WORKBOOK 112 • Let the solution sit in the system for up to 30 When to do processor control sensitometry minutes. Higher concentrations of hypochlorite • First thing every morning. or longer dwell times may harm some construc • After the processor has reached the correct tion materials. operating temperature. • Rinse the bleach from the system and dislodge • After feeding clean up film through. easily removable biogrowth. • Before processing any patient radiographs. • Scrub the biogrowth off accessible surfaces. Use • After cleaning or servicing the processor. a clean, stiff brush or other tools recommended, for cleaning the surface. • Flush the system thoroughly with water before . Outline of procedure returning it to normal use. • A standard step wedge image must be produced. DO NOT allow concentrated sodium hypochlorite bleach • This image consists of a range of clearly defined to come in contact with photographic processing so densities. lutions. Dangerous fumes can be produced. • Production of this image must be consistent. Methods for its production are described following. Summary daily solution checks of • The film is processed in the film processor to be Developer assessed. • Check temperature at least once a day (ideally 3 • The resultant image densities are determined times per day). using a densitometer, recorded, graphed and the • Check developer level at time of temperature graphs evaluated. check. • The first graph produced is known as a charac teristic curve. Fixer • To draw a characteristic curve, plot test film den • Check fixer level at time of temperature check. sities against test film density step numbers. Step l must be the lightest density. Water • From this characteristic curve, several other • Check water level and flow at time of tempera graphs may be plotted, each giving additional ture check. information. • This combined information will give a compre Sensitometry hensive picture of processor performance. Sensitometry is the study and measurement of the The test fflm relationship between exposures, films, screens and processing. The image on the test film must be a standard series of clearly defined densities, ranging from barely visible Principle use to black. • These densities are usually over a range of 21 • Our interest lies more in its use in checking film steps. processor performance, in particular that of au • A smaller number of steps may be used. tomatic processing. • Number the steps from l Clightest step). • By standardizing exposure, film and screen types, conditions under which films are exposed, han Producing the test film dled and stored, leaves only one variable, that of There are several ways of preparing the test film. film processing. • Any variation in film image must therefore be due METHOD I to film processing. The best and most reliable method is to use a • A very elementary form of evaluating film process sensitometer, which produces a standard range of ing performance has already been dealt with (see densities. Module 4. Manual processing, page 78). • Sensitometry is a more comprehensive and Using the sensitometer accurate form of monitoring processing • Use a dedicated box of film of the type commonly performance. used in your department. MODULE S. AUTOMATIC FILM PROCESSING 113 • Use the sensitometer in the darkroom where the • Standard conditions must be used each time a processor is to be monitored. step wedge image is made. • Select the light colour relevant to your films colour sensitivity (blue or green). METHOD 3 • Under safelight conditions insert a sheet of Producing a standard range of densities, using X-ray, film into the sensitometer until it reaches the without the step wedge. back-stop. • Press cover down and hold until signal (audio or Making the Image light) has stopped. • Place an 18 x 24cm cassette, loaded with your • Raise the cover and remove film. standard film, face up on the X-ray table. • Process the film in the processor to be monitored. • Divide the face of the cassette into 11 strips. • The film should always be placed in the same spot • Cover all but the end strip with lead rubber. on the feed tray, with the image parallel to the • Set a lOO cm FFD (SIDl, centre and collimate to rollers. the uncovered area (strip 1). • Expose using a low exposure (enough to produce METHOD 2 a barely visible density). Make an X-ray image of aluminium step wedge under • Move the lead rubber so that strips 1 and 2 are standard conditions. uncovered. • Using the same exposure, expose both strips (strip Mal Terminology To understand the process of sensitometry it is necessary to have an understanding of some basic terminology. Sensitometer A consistent light source, that produces a standard range of densities, when exposed on film. Densitometer A consistent light source, combined with a light meas uring sensor, used for accurately measuring film Fig 5-1. Making a sensitometry test strip density. using an aluminium step wedge QUALITY ASSURANCE WORKBOOK 114 Film density that is said to have a "wide latitude" has the ability to The degree of film blackening. You will see from the accept large changes in exposure, without excessive characteristic curve graph, and your own experience, density changes. that density increases as exposure increases. Carrying out the sensitometric test Contrast Frequency of test The difference between two or more densities on a film. • Daily. The straight line portion and shape of the characteris tic curve gives us information about contrast. A high Equipment required contrast film curve will lie toward the left, whilst a lower • Sensitometer, to produce image by Method 1 contrast curve will lie more to the right (see exposure described above, or latitude, page 116). • Step wedge to produce image by Method 2 described above, or Gradient • Lead rubber sheet and cassette to produce The contrast of a film at a given density. When a straight image by Method 3 described above. line is drawn tangent to the characteristic curve at a • Unexposed film or manufacturer's pre exposed particular density, this line forms the slope which is sensitometry film. the gradient of that density. • Densitometer. • Specialised graph paper supplied by a film manu Average fradient facturer, or A line drawn between the 0.25 and 2.00 density levels • Simple small grid, graph pape~ available from on the characteristic curve. stationary shops, drawn up in the same way. • Any scale graph paper may be used, but it is com Toe gradient mon to use a ratio, X axis toY axis of 0.15: 1.0. A line drawn between the 0.25 and 1.00 density levels The important thing is that you do not vary the on the characteristic curve. ratio once your quality control program is under way. Mid gradient A line drawn between the 1.0 and 2.0 density levels on Method the characteristic curve. • Allow the processor to stabilise. • Process the test film in the processor to be Upper gradient checked. A line drawn between the 2.0 and 3.0 density levels on • Tests must be carried out at the same time each the characteristic curve. day under the same conditions. • Developer temperature must be taken at the time Base plus fog of test. The density of a processed film, without the effects of • Using the densitometer, read the density of each light or radiation. The density at which the character step on the test film image. istic curve starts. • Record the densities against their step numbers. • Plot a graph of step numbers on the horizontal Exposure axis against densities on the vertical axis and join Intensity of radiation x time CmAs). up the plots (see Fig 5-2). Speed Indicated by the location of the curve along the step Using the densitometer (exposure) axis. A faster film curve will lie more toward • Switch on the densitometer and allow unit to the left, whilst a slower film will lie more toward the stabilise. right. To calculate film speed use a density level of 1.0 • Set densitometer readout to zero. (this is considered to be the average of the useful den • Place the centre of the density to be read, di sity range of 0.25 to 2.0). rectly over the aperture and under the reading arm. Exposure latitude • Lower the reading arm to the film, press the "read" The range of exposure factors, within which the result switch and hold for a few seconds, until the ant radiograph is considered to be acceptable. A film readout stabilises. MODULE S.AUTOMATIC FILM PROCESSING 115 Characteristic Curve - Speed • Select the step number that has a density GRAPH OF DENSITY/STEP :NUMBER within a range of 1.0 to 1.3 on the step wedge image. This step number becomes the speed step. • Record the step number on the speed chart in the space provided (speed step No ...... J. Do this only on day 1, after the chemistry has been freshly mixed. • Plot the density reading on the zero line under Day 1. Do this only on day 1, after the chemistry has been freshly mixed. • Measure and plot the density of the Speed 9 IOsTEP l' Characteristic Curve GRAPH OF DENSITY/STEP NUMBER lL 3.o H--1--+--+--+--+-+-+-+-+-+-+-+-,_L~-;-.,.....-r--r--r-""'1"1 _L 1/ I 2.0 H--t-+--+-+-+-+-t-H~-tj_ff-t-t---t---t--t--t--1--t--H V r. t.o t-t--t--t--t--r--t-+-+-+--t-...,.,..L--t---t-t-r--t--t-.,....-r--t--r-""'1"1"' V .T, lL _v 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 STEP NUMBER Speed Index = 1.06 Base+ Fog= 0.16 Average Gradient Contrast Index = 1.88 D-Max = 3.52 =3.08 Fig 5-l.An example of a characteristic curve • Take the temperature of the developer. • Record this against the zero line on the D • Record against the zero line of the Tempera Max Chart. Do this only on day 1, after the ture Chart. Do this only on day 1, after the chemistry has been freshly mixed (see Fig 5- chemistry has been freshly mixed. 3, Fig 5-4 and Appendix B, page 163). • Repeat this procedure daily, plotting the • Repeat this daily, recording the D-Max on the Temperature under appropriate dates (see chart under appropriate dates. Fig 5-3 & Fig 5-4 and Appendix B, page • Noticeable variations give advanced warning 163). of chemistry problems. • Observe how much the temperature varies. • Action should be considered if the tempera How to use the sensitometry graphs ture varies more than a few degrees. - D-Max All processors will show some variation in results from • Using the densitometer, measure the maxi day to day. However, action should be taken if the vari mum density step on the step wedge ations are sudden or continue to increase or decrease image. over a period of time and pass beyond the acceptable limits. MODULE S. AUTOMATIC FILM PROCESSING 117 Quality Control Processing Chart Processor: I Month: I Speed Speed Step No 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 +0.20 = ! i +0.15 :;; ! I +0.10 === I I +0.05 == ' I == I ~ I ! I -0.05 = : l I I -010 ~ I . ==~ i I -0.15 ~ I -0.20 Contrast 2 Steps Above No. 2 Steps Below No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 +0.20 ~ +0.15 = +0.10 = +0.05 ~ I f ' ~ I i ' -0.05 = . ' ~ ': I -0.10 = I ; -0.15 = I I -0.20 == i Base+ Fog 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 +0.06 ~ +0.04 = = I I +0.02 ~ I ~ -0.02 = I ~ i j -0.04 = I ! I -0.06 == Temperature 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 +4C ~ I I I I I +2C I l = I ' ~ I I i I I I I I i I -2 c =='------=" I I ! I I I I I I I -4C ~ I I I i I I I ! D-Max. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 I i ) : I : I I I I /I I I I I I i i I I I I I l Fig 5-4. Sensitometry charts for recording Speed, Contrast, Base+ Fog, Temperature and D-Max data QUALITY ASSURANCE WORKBOOK 118 If the change is sudden, then all possible influenc limits, especially if the change is sudden or continues ing factors should be checked, or a mistake may have to increase or decrease, then the processor is said been made. The test should be repeated. to be "out of control" and immediate action should be taken. In control: When results remain within acceptable limits the Action to be taken if the processor processor is said to be "in control" and no action is is out of control necessary. • Immediately stop using the processor. • Inform other users Out of control: • Start problem solving process If one or more of the charts (speed, contrast or fog) • File a report is showing results that are outside the acceptable Chart changes Possible cause Action • Speed and contrast First stage of over development l Adjust temp. increase 1 Developer temp. high 2 Adjust replenishment • D min acceptable 2 Excessive replenishment 3 Change developer 3 Developer too concentrated 4 Developing time too long • Speed & contrast up 4 Check processing time add starter • D min increases • Sudden increase in Excessive over development Add starter to developer Speed, D min & D Starter omitted or insufficient max after service Starter in developer • Speed decreases Under development l Check & adjust temp. • Loss of image l Developer temp. low 2 Check & adjust contrast 2 Developer exhausted replenishment • D min normal 3 Insufficient replenishment 3 Check & refill 4 Replenisher used up replenisher tank • Image density low 5 Developer too dilute 4 Replace replenisher over whole image 6 Developing time too short 5 Check processing time Speed & contrast low • D min also low • Sudden decrease in Excessive amount of starter Replace developeG add speed and D max in developer correct amount of starter after service • Small decrease in D min • Increase in speed l Aerial oxidation Replace developer after • Shoulder decreases 2 Contaminated developer washing out tank • Loss of contrast Add correct amount of • Increase in fog starter Fig 5-5. Example of the possible interpretation of sensitometric charts and recommended action. MODULE 5. AUTOMATIC FILM PROCESSING 119 Notes QUALITY ASSURANCE WORKBOOK 120 TASK 24 Sensitometry test JDWY ______DJ.TB EXPOSURB------~------ 4.0 4.0 E ~ E !:= ~ = !:= § t= § !:= g ~ g ~ = g ~ 1:: = E = ~ - .. :;: t:: I= .. E: g : = :;: = ~ !"=' 1:: g § e; ~ E E: E 3.5 t: 3.5 !=:' § § § : - t:: ~ ~ = !:= : STEP DENSITY ~ E E E .F ;_ ~-- ~ E ~ = § = - E: - !; ::: 1 ; = ~ E g § g I= f e; t: t: = = E: ;:: g g F ::: 2 = ::: - ~ - ::: § 3 - I= E ~ ~ E = ~ = : 3.0 ; t: = : 3.0 4 ~ § ~ ~ E ~ ~ ~ § ~ § ...... ~ = = 5 E E E ~ § -= ~ ~ ~ = = § § § § § - : ~ :::: E !:= ::: g g 1::: ::s g ~ ~ ~ = = ~ ~ - E E E !:: t: ~ 7 ~ = - ~ = E § .. § § § g E ; ; 2.5 B = = ~ J 2.5 9 t: § ::: § ;:: :: ~ ~ - § ~ :: E !=:' : § 10 g § § ~ E ;; : ~ ~ - g ;:: ..= § 11 E ~ - - ;:: E -E r::= g § = E12 § = - .... - 1: t: ~ - 13 § ; - E ~ ~ = = § e g !:= E 2.0 :: 2.0 -14 :: ~ - E § _g ;: ::: g E: g ~ 15 ::: .- :: .....- - E 16 = g .. = .:: = ;: § = = ::: E ::: :: 17 ~ := ... - e :: § § § e; - :r:: E: - 18 § t: ~ - E - :: § ~ § § § - 1.5 ::: t: ::: E: E: :: 1.5 19 ; = - - r ~ - - 20§ ::: ::: - - § - ~ E: ; § :: :: = E: = = g ~ § t: ::: E 21::: - = - - - = = - § § t: t: = = - ·- - ~ - E: ::: ::: - : - :: t: ; :: § § § ;_ ~ ::: 1.0 - - - - - 1.0 ::: - § § § = - E - :: :: ::: ::: - ::: ; ::: ::: -!§ ::: = ::: ::: - - ~ - - t: - ; .... g - :: E § E E E ::: - !: E: .... - E [ E - = § ~- E 1::: - ; § § § ...t: E: ·- !: 0.5 - F - = = - 0.5 E: § I= = ::: c: - 1::: E - = t= !=-_ E_ e e; : .... =t= = ;; = I= E ::: = - E c E.... ::: E ..- § g ::: = ;:: E - E ::: - - E. § = g :: g ::: :: ~ ;:; ~ E :: e § - = E I:' = ~ - :: - g :: ::: g 0.0 - e - - ~ ~ - 0.0 ltep no. 3 5 7 9 ll 13 15 17 19 21 23 MODULE S.AUTOMATIC FILM PROCESSING 121 You are required to carry out the daily monitoring sensitometry check of your processor. a) Select an automatic processor. b) Carry out the routine sensitometry test. c) Plot the Characteristic Curve on the graph sheet below. d) Answer the following questions in the spaces provided. l. How does this graph compare with the Characteristic Curve shown in the notes? 2. Give the following figures: SPEED CONTRAST ______BASE+FOG ______D-MAX Include your step wedge film with these answers. Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor QUALITY ASSURANCE WORKBOOK 122 TASK 25 utomatic processor start up routine You have been asked to start up the automatic processor at the beginning of a working day. a) Select an automatic processor. b) Carry out the automatic processor start up routine using the following check list. c) Answer the following questions in the spaces provided. Checl< Satisfactory/Unsatisfactory Comment Developer level Developer replenisher level Developer replenishment rate Developer condition Developer temperature Fixer level Fixer replenisher level Fixer replenishment rate Fixer condition Water flow Condition of rollers Condition of drive cogs Drive motor Dryer MODULE S. AUTOMATIC FILM PROCESSING 123 Feed warning signal Passage of clean up film Abnormal noises Cleanliness l. What was the developer replenishment rate? ______ 2. What was the fixer replenishment rate?------ 3. What was the developer temperature?------ 4. What are your recommendations? Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor 124 MODULE 6 Radiographic exposures Aim mA • Controls the intensity of radiation and there To provide sufficient knowledge of exposure selection fore film density and patient dose. The higher and manipulation, to enable accurate selection of ex the mA, the higher the film density and patient posures, in order to produce maximum information on dose. the resultant radiographs. time Objectives • Controls the length of time of radiation flow, and therefore film density and patient dose.The longer On completion of this module the student will the exposure time the higher the film density and 11 Understand the effect each exposure factor has patient dose. on the resultant radiograph. • Be able to use this knowledge effectively. mAs • Be able to select the correct exposure factors • The multiple of mA and time (in seconds). required. • Many modern X-ray units are designed to use mAs 11 Understand and use the step system of exposure rather than mA and time separately. calculation. 11 Be able to manipulate exposure factors using the FFD (SID) step system. • The greater the distance an X-ray beam travels li Be able to establish and maintain a reliable the less effective it will be, the less distance it exposure chart. travels the more effective it will be. li Be able to modify an existing exposure chart. • Exposure compensation is therefore necessary with changes in FFD (SIDl. Strictly speal Here we will deal with: • Measure the thickness of the patient's hand in • Establishing and modifying an exposure chart. all projections used. e.g. PA, Oblique, lateral (see • Manipulating exposure factors using the step Module 2. Accessory equipmen( page 41 and system. Appendix A, page 135). • Measure thickness at the level of entry of the Establishing an exposure chart central ray, for each position of the hand. • Measure all other areas/positions in the same Method group (these can be obtained from a colleague • Draw up a blank exposure chart (see Fig 6-l and or ft·iend of similar size rather than inconvenience Appendix B, page 168). the patient). • Fill in all the anatomical areas to be covered, list • Calculate the exposures for all other areas/posi ing the views for each. tions in the group, based on the following chart • Divide these into groups using the same set of (patient thickness related to exposure change), conditions. e.g. all extremities using detail screens, using the hand as your base level: no grid, lOO cm FFD (SIDl. • Produce a well exposed set of radiographs of an Patient thickness related to exposure change extremity, e.g. hand. (this can be done in the - 1.5 cm increase in thickness requires a 25% course of a routine examination.) increase in exposure (+ l step) • Record the exposures used against HAND on the - 5.0 cm increase in thickness requires a lOO% chart. increase in exposure (+3 steps) Exposure chart Room ______ Area kV mAs mA Time FFD (SID) cm Grid Screens Remarks Hand PA lOO - Detail Oblique lOO - Detail Lateral lOO - Detail Wrist PA lOO - Detail Oblique lOO - Detail Lateral lOO - Detail Forearm AP lOO - Detail Lateral lOO - Detail Elbow AP lOO - Detail Oblique lOO - Detail Lateral lOO - Detail Foot DP lOO - Detail Oblique lOO - Detail Lateral lOO - Detail Ankle AP lOO - Detail Oblique lOO - Detail Lateral lOO - Detail i I l Fig 6-I.An example of a partially completed exposure chart QUALITY ASSURANCE WORKBOOK 126 - 5.0 cm decrease in thickness requires a 50% Note: Step changes can be applied to any one of the decrease in exposure C-3 steps) charts or split between the charts. - 1.5 cm decrease in thickness requires a 23% • The step system provides step charts for kV, mA, decrease in exposure C-1 step) mAs, time and FFD CSIO), • Any step change required to modify an exposure • An increase of 10 kV =three steps on the kV step can be applied to any of the Step Charts, although chart. other factors will influence this decision (contrast, • To retain the same density film, the mAs must be penetration, patient dose, movement, limitations reduced by the same number of steps (three of the X-ray unit). steps) on the mAs chart. • Step changes need not be limited to one chart • New Exposure= 70 kV 10 mAs only. The necessary step changes can be split up between charts if necessary, providing that the Step charts overall number of required step changes is made. All step charts reproduced from "Course Notes in Ba Example sic Radiography", Radiation Protection Branch, South • Original Exposure= 60 kV 20 mAs Australian Health Commission. • New kV = 70 kV (an increase of 10 kV) Exposure modification for changes in conditions Pathology Step changes suggested Ascites +2 Asthmatic -1 or 2 Bowel Obstruction -1 or 2 Emaciated 0 Emphysema I -1 or 2 f ~ "Flabby" Fat -1 I Muscular Physique +1 I Osteoporosis -1 or 2 Paget's Disease +1 or 2 Pleural Effusion +1 or 2 Pneumonia +1 or 2 Pulmonary Oedema +1 or 2 Tuberculosis +1 Plaster of paris Half +1 or 2 Dry +3 Wet +4 or 5 Fibreglass 0 or +1 Grid Up to Ratio 8.1, 40 lines/cm at 80 kV +5 Screens Detail to Fast -3 Fast to Detail +3 (idealiy use mAs steps) Note: These step changes are a guide only.You may need to modify this chart to suit your own conditions. Fig 6-5. Suggested step changes for specific changes in conditions QUALITY ASSURANCE WORKBOOK 128 Notes MODULE 6. RADIOGRAPHIC EXPOSURES 129 TASK 26 Radiographic exposures You have been asked to complete the exposure chart shown below a) Calculate all other exposures on the chart1 based on the information given against DP Foot and AP Hip. b) Fill in all other relevant information. Exposure chart Area kV m As Thickness FFD Grid Screens of Part csrm cm cm Foot DP 50 10 8 lOO Detail Oblique Lateral Ankle AP Oblique Lateral Tibia & fibula AP Lateral Knee AP Lateral Femur (Lower 2/3) AP Lateral Hip AP 70 50 18 lOO Bucky Fast Lateral Pelvis AP I Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor QUALITY ASSURANCE WORKBOOK 130 TASK 27 Modify an exposure chart Your department has just been supplied with new intensifying screens and your exposure charts are no longer accurate. Someone has worked out some exposures already and has asked you to modify the remainder. a) Modify the following exposure chart. b) Start by replacing the relevant exposures with the following exposures. HAND, PA 50 kV 8 mAs SHOULDER,AP 65 kV 16 mAs CHES~ PA lOO kV 5 mAs c) Now modify all other exposures on the chart, using the step charts. d) Enter the new exposures alongside the old ones. Exposure chart Area kV m As FFD cm (SID) Grid Screen Hand PA 50 16 100 No Detail Oblique 50 20 100 No Detail Lateral 50 32 lOO No Detail Wrist PA 50 16 100 No Detail Oblique 50 20 100 No Detail Lateral 50 25 lOO No Detail Forearm AP 55 20 100 No Detail Lateral 55 25 lOO No Detail Elbow AP 55 25 lOO No Detail Oblique 55 25 lOO No Detail Lateral 60 20 lOO No Detail Humerus AP 60 32 lOO Bucky Fast Lateral 60 32 lOO Bucky Fast Shoulder AP 65 32 100 Bucky Fast SI 65 32 100 Bucky Fast Chest PA 90 5 180 Bucky Fast Oblique 90 5 180 Bucky Fast Lateral 100 5 180 Bucky Fast MODULE 6. RADIOGRAPHIC EXPOSURES I 3 I Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor QUALITY ASSURANCE WORKBOOK 132 TASK 28 Creating a new exposure chart Your department has just been equipped with a new X-ray unit and you have been asked to produce an exposure chart for it. a) Select an X-ray room. b) Using the knowledge you have gained to date, establish a completely new exposure chart, for the X-ray unit in that room. c) Draw up a chart and fill in all relevant information on your chart. e.g. patient positions, exposure factors, grid, screens, FFD CSID), patient size. d) Submit the chart to your tutor for assessment. Tutor's comments: Satisfactory/Unsatisfactory Signed Date Tutor 133 APPENDIX A Making simple test tools Water phantom • Several books or phone directories. • A pile of particle board (chip board) sheets. Purpose • To simulate a patient. • To provide an overall even image. Aluminium step wedge Purpose Equipment required • To produce a standard range of densities on film. • 20 litre plastic flagon (other plastic containers • Sensitometry. of a suitable size can be used). • Film comparison. • Ruler. • Generator output consistency. • Thick tipped waterproof marking pen. • mAs consistency. METHOD I Equipment required • Aluminium block1 105 mm long x 42 mm high. • Hacksaw. • File. • Pencil. • Rule. Method • Draft a template and stick it on the side of the aluminium wedge or draft the measurements directly on to the aluminium • Cut or file the sloping surface of the wedge into 21 steps, each 5 mm long and 2 mm high. • Check that the height of each step is accurate. • Smooth off rough edges. Fig A-l. Plastic flagon being used as an X-ray phantom Method • Lie the container on its side • Using the pen and the ruler1 mark the side of the container with various depths above the lower side of the container (lO cm 1 20 cm and 30cm). • The container can be filled with varying depths of wate~ depending on need. Note: Other items that can be used: • Aluminium or wax block. Fig A-2.Aiuminium step wedge QUALITY ASSURANCE WORKBOOK 134 METHOD 2 • Box of large headed tacks, drawing pins or staples. Equipment required • An aluminium strip 1.2 meters long 10 mm wide Method and 2 mm thief<. • Make up the frame if necessary. • Adhesive suitable for gluing aluminium. • Tack the wire mesh/perforated sheet to the frame • Hacksaw. so that it is perfectly flat. • File. • Pencil. • Rule. Method • Cut the aluminium strip into 21 shorter strips. • The first strip must be 105 mm long. • The remaining 20 strips must be cut progressively 5 mm shorter than the preceding strip, making the last strip 5 mm long. • There may be a little wastage. • Place the strips one on top of the other, star ting with the longest and getting progressively smaller until a series of even steps have been built up. • Glue the strips together. Fig A-3. Perforated zinc sheet-used as film/ • Place the vertical end of the wedge against a firm screen contact test tool upright surface and tap each strip back against it. • Leave to harden. • Smooth off the rough edges. Note: The wire mesh/perforated sheet can be used without Note: the frame, provided it is kept perfectly flat. Care must • The dimensions of the step wedge are not criti be taken not to bend or damage it. Plastic sheets can cal providing, the steps are standard. be mounted either side to protect it. • A simple step wedge can be made with only 11 A small hole, approximately 2 cm square, sited about steps. 10 cm from one edge of the sheet helps to gauge the • The steps need not necessarily be glued, but are correct exposure and film density (densitometer less likely to get lost if they are. readings would be taken here). Film/screen contact test tool Spinning top timer test tool Purpose Purpose • To test for poor film/screen contact within a • Check accuracy of X-ray unit timer. cassette. Equipment required Equipment required • Brass or mild steel disc, 100 mm in diameter, 2- • A sheet of fine gauge wire mesh or sheet of thin 3mm thick. perforated zinc (do not use aluminium). • Steel disc 60 mm in diameter, 10 mm thick. • The size of the sheet should be slightly larger than • Small steel block 20 mm x 20 mm x 20 mm. a 35 x 43 cm cassette. • Bolt 3 mm thief<, 40 mm long, with 2 nuts and a • An old picture frame with an internal measure countersink head. ment slightly larger than a 35 x 43 cm cassette, • Drill and 3 metal drill bits, 3 mm, 5 mm and a or timber to make a frame. countersink bit. • The frame and wire mesh/perforated zinc must • Spanner. be compatible in size. • File. APPENDIX A. MAKING SIMPLE TEST TOOLS 135 • Pencil. • Rule. • Welding outfit. Method 1 • Weld the small steel block to the centre of the large diameter disc. • Drill a 5 mm hole through the centre of the larger disc and 15 mm up into the small block. (do not drill right through the small block). • File all sharp edges off the small block. Cal • Drill a 3 mm hole in the large disc 10 mm from its outer edge. • Drill a 3 mm hole right through the centre of the smaller disc and countersink one end of the hole. • Insert the bolt into the hole in the smaller disc/ so that the head is countersunk below the sur face of the disc and fix firmly in place with both nuts. • File the tip of the bolt to a point. • Place the smaller disc on a firm surface with the bolt up. • Hold the larger disc by the small welded block • and fit the sharpened bolt into the central hole in the larger disc. • By holding the small welded block the larger disc can be spun. (b) Fig A-S.A simple brass spinning top, (a) assembled ready for use, (b) with top lifted to show base Measuring callipers Purpose • Measuring patient thickness in order to calcu late exposure (see Module 6. Radiographic expo sures, page 124). Equipment required • 2 strips of aluminium 600 mm long, 20 mm wide, Fig A-4.A commercially made spinning top 2 mm thick (mild steel may be used, but it is more difficult to work with). • Drill and 2 mm metal drill bit Cor felt tip pen). Method 2 • Hacksaw. • A wooden block or section of broom handle can • File. be used instead of the small steel block, previ • Pencil. ously described/ and fixed in place with two • Ruler. screws, after first drilling the disc to accommo date the screws. Method • A wooden base 150 mm square can be used in • Form a flattened loop at one end of one of the stead of the smaller of the metal discs. strips1 forming aT shape. QUALITY ASSURANCE WORKBOOK 136 • This flattened loop should fit snugly over the other strip and slide up and down it. • Bend the second strip to form a 90 ° angle. • File all rough edges smooth. • Slide the flattened loop over one end of the other strip of metal. • Adjust so that the one strip slides easily up and down the other. • Check that the two opposing arms are parallel to one another. • Measure the distances in centimetres between FigA-7. Diagram of a the tomography test the bottom of the adjustable arm and the op tool described in Method I posing fixed arm. • Mark these distances on the arm that the move Method able arm slides on. • Accurately measure from the base of the block, • A hacksaw blade can be used to mark the metal, up the vertical side, marking the block every 1 cm. or drill small holes. • Repeat along the base. • The numbers can be written against the marks • Draw in the intersecting lines. with felt tip pen. • Partially hammer in nails, to the same depth, at the intersection of every line. • It is important that the height of each nail above Moveable Arm the base is accurate. • Mark each horizontal line with its height above the base. • On the resultant film the nails/pins that are clearly / defined are those at the level of the tomographic cut. Note: A polystyrene block and sewing pins can be used instead of the wood and nails. METHOD 2 Equipment required Fig A-6. Diagram of simple measuring • Strip of fine metal gauze (the dimensions of the callipers strip of gauze should match those of the sloping surface of the wedge). • Set of small lead numbers 1 to 9. • Small tube of adhesive. Tomography test tool • Rule. • Pen or pencil. Purpose • To check the accuracy of tomography cut levels METHOD I Equipment required • A wooden wedge 15 cm base x 15 cm vertical x 21 cm slope and approximately 3 cm wide. • Ruler. • Pen or pencil. • 91 small nails 2-3 cm long. Fig A-8. Diagram of the tomography test tool • Hammer. described in Method 2 APPENDIX A. MAKING SIMPLE TEST TOOLS 137 Method X-ray beam/grid alignment test tool • Measure and mark every 1 cm along the base, as Purpose in method 1. e To check the alignment of the X-ray beam to the • Draw in the vertical lines and measure the height grid lines. of each one. • Write the height against each line. Equipment required • Place the metal gauze on the sloping surface and • Sheet of lead or lead rubbe~2 to 3 mm lead equivalent. fix with adhesive. • Drill and two drill bits, one 2 mm and one 10 mm. • Glue the lead numbers on the surface of the • Knife or hacksaw. gauze, keeping them all toward the outer edge on the same side. Method • Cut the lead into one strip measuring 230x 50 mm Note: 1. A polystyrene block can be used instead of and two strips measuring 90 x 50 mm each. wood. • Drill five 10 mm holes in the large lead strip. 2. If difficulty is experienced in producing a clear • Drill two 2 mm holes in the large lead strip, one enough image of the mesh, try placing a strip either side of the central 10 mm hole. of thin lead (the thickness of that used in the • Drill a group of three 2 mm holes at one end of back of cassettes), or copper, under the test the large lead strip. tool. • See diagram below for measurements. 90mm =-I t 50mm L....--_j_ 40mm -=- 0 0 t 0 50mm 0 0 0 0 0 j_ 230mm ~I Large holes -lOmm diameter. Small holes- 2mm diameter. I Material: 2mm Lead sheet or Lead rubber sheet. I X - ray Beam/Grid Alignment Test Tool. fig A-9. Diagram of an X-ray beam/grid alignment test tool with dimensions 138 APPENDIX B Graphs, check sheets & record sheets Reject film analysis Daily totals Period: From ______To ______ Cause Daily totals Weekly totals Dates Projection Movement Under exp. Over exp. Static Fog (darkroom) Fog (cassette) Equipment Processing Other Totals Total film rejected: ______Total film used: ______Rejected film as a percentage of film used: ______Cost of film rejected this week: ______ Comments/action APPENDIX B. GRAPHS, CHECK SHEETS & RECORD SHEETS 139 Reject film analysis Daily totals by film size Date: ______ Film size cm No. of films Amount of film Csq. m) 1 35 X 43 2 35 X 35 3 30 X 40 4 24 X 30 5 18 X 24 6 18 X 43 7 Dent I Occ 8 Other Totals Total number of films: ______Total square meters of film : ______Cost of rejected film today: ______ Comments/action QUALITY ASSURANCE WORKBOOK 140 eject film analysis Daily totals by location Date: ______ Cause Location Room l Room 2 Room 3 Room 4 Total Projection Movement Under exposed Over exposed Static Fog (darkroom) Fog (cassette) Equipment Processing Other Total Total films rejected today: ______ Comments/action APPENDIX B. GRAPHS, CHECK SHEETS & RECORD SHEETS 141 Remedial action record Following reject film analysis Date reject film analysis completed ______ ! Date started Remedial action Date finished Outcome I QUALITY ASSURANCE WORKBOOK 142 Collimator check records Room ______FFD CSID) ____ Light field size ____ kV ___ mA ___ Sec ___ mAs ___ Date Light/X-ray Visual Electrical Shutter Remarks coincidence test inspection inspection efficiency A B c D • The letters A,B,C,D, under "Light/X-ray coincidence test" above, refer to indi vidual collimator shutters, "A" being the shutter on the control knob side, then rotating clockwise. • Record the difference in mm between the light and X-ray images, indicate if the light field is outside or inside the X-ray field. APPENDIX B. GRAPHS, CHECK SHEETS & RECORD SHEETS 143 Record of all cassettes No. Size Type of screens Date Date cassette cm I fitted put into service i i I I l i I I I i 'I I I I I I I QUALITY ASSURANCE WORKBOOK 144 Cassettes and screens Maintenance and testing Record dates of maintenance/tests Cassette Screen Film/screen Screen Cassette Cassette Comment No. comparison contact test cleaning maint. light tight test test APPENDIX B. GRAPHS, CHECK SHEETS & RECORD SHEETS 145 Cassettes and screens Routine maintenance and cleaning record Date Cassette numbers Comments I ! QUALITY ASSURANCE WORKBOOK 146 Lead rubber aprons and gloves Testing record Dates inspected Fasteners Cover Stitching X-ray test Hangers Are hangers used? Cleanliness • Enter the date checks carried out • Place a tick in the box if satisfactory • Place a cross in the box if unsatisfactory and enter comment below Comments: (Enter date, comment and signature) Date Comment Signature APPENDIX B. GRAPHS, CHECK SHEETS & RECORD SHEETS 147 Viewing box Maintenance and inspection I Dates inspected I Position Safely fixed I Light -even - brightness Electrical -plug -wiring -switch I - tubes - starters Window Film clip I ' Cleanliness - inside - outside Other Comments: (Enter date and signature) Date Comment Signature QUALITY ASSURANCE WORKBOOK 148 Fault report To be completed by person reporting fault Name Time Date Room Priority (circle a number) 1 2 3 4 5 6 7 8 9 10 urgent not urgent Description of problem (Please be specific) Signed Action Signed Outcome Signed APPENDIX B. GRAPHS, CHECK SHEETS & RECORD SHEETS 149 Equipment record Room No. ______ X-ray generator Manufacturer ______Supplier ______ Model ______Serial No. ______ Date installed ______Date accepted ______ Warranty expiry date ______ Sing phase ______Three phase ______ Maximum kVp ______Maximum mA ______ X-ray tube Manufacturer ______Su pp Iier ______ Model ______Serial No. ______ Focus sizes Broad ____ Fine ____ Warranty expiry date ______ Date installed ______Date accepted ______ Tube suspension Manufacturer ______Supplier ______ Model ______Serial No. ______ Mounting-Floor/Ceiling ______Locks-Manual/Magnetic Date installed ______Date accepted ______ Warranty expiry date ______QUALITY ASSURANCE WORKBOOK ISO Collimator Manufacturer ______Supplier ______ Model No. ______Serial No. ______ Light switch-Clockwork/Electronic Warranty expiry date _____ Date installed ______Date accepted ______ Table Manufacturer ______Supplier-~------Model No. ______Serial No. ______ Movement-lilt/Fixed Potter-Bucky-YES/N 0 Potter-buci Upright potter-buci Manufacturer ______Supplier ______ Model No. ______Serial No. ______ Grid Ratio ______Grid line ______ Focal range ______Grid movement-YES/NO Date installed ______Date accepted ______ Warranty expiry date ______ Control panel Manufacturer ______Supplier ______ Model No. ______Serial No. ______ Date installed ______Date accepted ______ Warranty expiry Date _____ APPENDIX B. GRAPHS, CHECK SHEETS & RECORD SHEETS 151 Stationary grids Manufacturer Supplier Model Serial No. Grid ratio Grid line Focal range Date supplied Notes QUALITY ASSURANCE WORKBOOK 152 Equipment maintenance and repair log Date Action Repair Service QC hours hours hours APPENDIX B. GRAPHS, CHECK SHEETS & RECORD SHEETS 153 X-ray unit Record of visual/manual quality control checks Room No. ______Pass="' Faii=X Does not apply= NA Date Tube and FFD Scales tube Angulation indicator suspension Locks (aiD Perpendicularity Collimator Tracks High tension cable/other i cables Cleanliness Table and Bucky mobility upright ' Bucky lock f bucky Cassette lock Bucky grid movement I ' Cables I I I I Table I Cleanliness i I i I Control Hand switch and cable panel Panel switches, lights and meters j I I Technique charts i I I I Overload protection 1 I I Cleanliness i ' I ! QUALITY ASSURANCE WORKBOOK 154 Fluoro. Locks Call) system Power assist Motion smoothness Switches/lights/meters Compression device Fluoro. monitor Fluoro. grid Fluoro. timer Fluoro. shutters visible Cleanliness Other Gonad shield, aprons and gloves Measuring callipers Stationary Grids Patient Positioning Aids APPENDIX B. GRAPHS, CHECK SHEETS & RECORD SHEETS 155 Constancy of radiation output at different mA settings Test record Room ______X-ray Unit ______kV ______Focal Spot. Size ______FFD ______ Exposure l Exposure 2 Exposure 3 mA Time mAs I Dates I I l I 6 I I I 5 Darker 4 3 2 l l Control 0 l 2 I 3 I I Lighter 4 :; 5 I :1 I ]I I' I 6 I I ! • The numbers represent step differences between test films and control film. • Plot step differences under dates. QUALITY ASSURANCE WORKBOOK 156 Darkroom inspection checklist Location ______Date ______Inspected by ______ Item 01< Not 01< Comments Darkroom: • Ten'lperature Cl0-20 °C) • Humidity (40% to 60%) • White light leaks. • Ventilation. • Clean & tidy. Safelight: • Working. • Filter faded or cracked. • Correct distance from bench. • Leaking white light. • Correct wattage light bulb. • Safe for film handling time. Film hopper: • Firmly anchored. • Earthed. • Damage free. • Works effectively. Bench top: • Earthed . • Damage free. • Clean. Processor: • Working 01<. • QA checks carried out. • Clean. Accessory equipment: • Timer. (working) • Chemical mixing paddles. • Thermometer. (working) • Aprons, gloves, goggles. (damage free, clean) • Name printer. (working, clean) APPENDIX B. GRAPHS, CHECK SHEETS & RECORD SHEETS 157 Specific gravity/temperature graph S.G. 1.088 1.087 1.086 1.085 1.084 1.083 1.082 1.081 1.080 1.079 • 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 Temperature o C QUALITY ASSURANCE WORKBOOK 158 Automatic processor Daily checks record Developer: Fixer: Water: Cycle: Repl. Rate ___ Repl. ___ Exch. rate ___ lime ___ Temp. ___ Temp. ___ Temp> ___ Dryer temp. ___ Two week period: Commencing ______Ending ______ DATES Dev. temp Water temp Dryer temp. Developer repl. Rate Fixer repl. Rate Cross over rollers Cleaned Circulation Check Water flow Rate Feed tray Cleaned Micro switches Checked Filters changed Bi monthly****** Remember that filters must be changed monthly APPENDIX B. 'GRAPHS, CHECK SHEETS & RECORD SHEETS 159 Automatic processor Checklist and periodic replacement of parts Replacement parts Replacement period a Springs, gears, shaft retainers, and E rings. Every year b Fuses, temperature control le~ safety thermostat, and Every two years developer submerged rack rollers. c Fixer submerged rack rollers, wash water Every three years sub-merged Rack rollers, and dryer rack rollers. Inspection period (months) 12 24 36 48 60 Replacement a * * * * * parts b * * c * (* ... replacement period) Checl< list Racl< sections, drive systems • Rack looseness and geometry • Rack shaft retainers, gear wear • Rack helical gear looseness • Rack roller foreign matter buildup • Drive motor chain tension • Abnormal noises Replenishment system • Photoelectric detection section function • Developer and fixer replenisher amounts check • Replenisher solenoid valve function • Replenisher pump function Circulation and temperature control systems • Processing tank internal foreign matter buildup • Supply hose solution leaks • Developer temperature check • Fixer temperature check • Circulation pump functions • Dryer system • Dryer section temperature check Miscellaneous • Finished product photographic quality • Upper lids, lower lids, and side plate checks • Water supply and ventilation checks -Q O'C: OJ> r- Processor maintenance checklist :::j -< Processor Type Month ______3> Ill Developer type Developer temperature Cycle time ______Illc: Developer replenishment rate Fixer replenishment rate Water temperature ____ ~ z n "' ~ Daily checks Date l 2 3 4 5 6 7 8 9 l l l l l l l l l l 2 2 2 2 2 2 2 2 2 2 3 3 ;:11:1 0 Dev. temp. 0 l 2 3 4 5 6 7 8 9 0 l 2 3 4 5 6 7 8 9 0 l 0 ~ Water temp. Dryer temp. Cross over rollers cleaned Dev. replenishment rate - Fixer replenishment rate Recirculation check Water flow Feed tray cleaned Check micro switches Bi monthly checl Developer activity chart Developer Activity 5 6 7 8 9 10 22 23 24 25 26 27 28 29 30 31 5 ~ 4 ~ 3 Positive 2 ~ ~ 0 === ~ 1 ~ • 2 Negat1ve I 3 ::=:::::: i ::=:::::: I ! I 4 ::=:::::: 5 l QUALITY ASSURANCE WORKBOOK 162 Characteristic curve chart Characteristic Curve IPROCESSOR : IDATE: 4.0 4.0 SPEED INDEX CONTRAST INDEX t== AVERAGE GRADIENT F:t== BASE+FOG F= D-MAX. 3.5 3.5 ~TEI DENSITY F= I= 1 l-e t: 2 f- 3 j::_t: 4 I= 3.0 3.0 5 6 l:: F:t: 7 I= 8 9 F= 2.5 2.5 10 t::: 11 F: 12 ]::_t: 13 ~ 14 2.0 2.0 15 t: 16 f- t: != 17 F ~ 18 f::t== F:t: 19 E t: 1.5 t::: 1.5 20 F= I= t== t: 21 I= != F: E E F= F: 1.0 1.0 f- ~ F= r ~ F= F t== I= F: f- F= t= != t: t: F: I= F: I= F F I= 0.5 0.5 F: F:t: F= F= t: 0.0 0.0 3 5 7 9 11 13 15 17 19 21 23 APPENDIX B. GRAPHS, CHECK SHEETS & RECORD SHEETS 163 Quality control processing chart ~· ,, Quality Control Processing Chart Processor Month J--: ) : -·} i ; ; ······· ~ i"' . .. : .. l'f------::----,-:---:-:--Sp_ee_d______---ij .~- .I Speed Step No _ .-~(" --~ ., ,, ': .'.: :::: .: ·:·.. ·'_ "' +_2 c .. :I·· .. -~··· . ;;,: .. ~ .1::' ...· - . :. . ·...... _::: .. :·· · .. ·:.·.·.:: . -2C := .. . :.. ;: · . ,. = ' '" .... " .:4C 1: ~-= D- Max --·1--T-..;:2,.-'3;'--'4T• _s:.,...;;G,...;.7r--'BT--'-9r. 1.;.0;...;1...;.1,.;.12,.-'1'-'3.-14_,.r1'"'5r1-'-6r·1;..;7"T""1""'Br1-'9'-r-"2"'orz1..-'2"'2r2"13r2;;_4,_."'z-'-sr· 2:;..6i',""'2"""7r• 2"-a,._2_9r; _3()"i'r3"'"i1 QUALITY ASSURANCE WORKBOOK 164 Exposure chart FFD Pat. mA (SI D) Examination meas. I HAND AP/PA/Obl. lOO Detail Lat lOO Detail WRIST PA lOO Detail Lat. lOO Detail FOREARM AP lOO Detail Lat. lOO Detail ELBOW AP lOO Detail Lat. lOO Detail HUMERUS AP lOO Fast Lat. lOO Fast SHOULDER AP lOO Fast SI lOO Fast TransThoracic lOO Bucky Fast Clavicle AP lOO Bucky Fast Clavicle I lOO Bucky Fast Scapula AP lOO Bucky Fast Scapula Lat. lOO Bucky Fast CERVICAL SPINE AP l-3 lOO Bucky Fast AP 3-7 t lOO Bucky Fast Ob I. 180 Bucky Fast Lat. 180 Bucky Fast Lat. Supine 180 Stat. Fast CERVICO THERACIC SPINE I AP I lOO Bucky Fast ' Lat. i lOO 1 Bucky Fast Swimmers I I lOO Stat. Fast QUALITY ASSURANCE WORKBOOK 166 THERACIC SPINE AP lOO Bucky Fast Lat. Upper lOO Bucky Fast Lat. 10-12 lOO Bucky Fast LUMBAR SPINE AP lOO Bucky Fast AP L5-Sl i lOO Bucky Fast PA lOO Bucky Fast Ob I. lOO Bucky Fast Lat. lOO Bucky Fast Lat. L5-Sl lOO Bucky Fast SACRAL SPINE AP i lOO Bucky Fast Lat. lOO Bucky Fast COCCYX AP i lOO Bucky Fast Lat. lOO Bucky Fast CHEST PA 180 Bucky Fast Ob I. 180 Bucky Fast Lat. 180 Bucky Fast Lordotic 180 Bucky Fast RIBS AP Upper lOO Bucky Fast Obl. Upper lOO Bucky Fast AP Lower lOO Bucky Fast Obl. Lower lOO Bucky Fast STERNUM Obl. lOO Bucky Fast Lat. lOO Bucky Fast Lat. 180 Bucky Fast SCJ Ob I. lOO Bucky Fast Lat. lOO Bucky Fast Lat. 180 Bucky Fast APPENDIX B. GRAPHS, CHECK SHEETS & RECORD SHEETS 167 PA Close Distance 60 Bucky Fast SI Examination Pat. I Now that you have completed the course your lmowl 4. Grid ratio is: edge of the subjects should be much greater. You a) The ratio of the height of the lead strip to should now complete this post course test and its thickness. compare the results with the results of the pre course b) An indication of the focal range. test. You will then have an idea of how much knowledge c) The height of the lead strips to the distance you have gained from the course. between them. Instructions 5. To test the alignment of the X-ray beam to a grid, the following test tool should be used: This is a multiple choice test. In each question you are a) A sheet of perforated zinc. given three possible answers. Read each question carefully. b) A lead strip with a series of l cm holes in it. Indicate the answer that you feel is the most cl Eight coins. accurate by placing a "X" in front of the letter preced ing it. 6. To test a lead rubber apron for cracks: All questions must be answered a) Use fluoroscopy. b) Feel it. 1. Intensifying screens must be cleaned by using: c) Hold it up to the light. a) Plenty of water. b) Small circular motions followed by top to 7. Lead rubber items should be tested every: bottom sweeps. a) Month. c) Pouring screen cleaner onto the screen then wiping off. b) 6 months. c) Once a year. 2. Film/Screen contact test tool can be: a) Plastic sheet. 8. Setting up a reject film analysis you should: b) Perforated aluminium sheet. a) Count all the unexposed films. c) Fine metal mesh. b) Count only the film boxes in the film store. c) Carry out the analysis without the staff knowing. 3. Blue light emitting intensifying screens should: a) Be used with blue sensitive film. 9. A reject film analysis could indicate: b) Be used only for extremities. a) Which is the most common fault. c) Need an exposure reduction of 10 kV. b) How much money has been wasted. c) Both of the above. QUALITY ASSURANCE WORKBOOK 170 10. The wattage of a safelight bulb should be, if fac- 18. A step wedge is: ing down: a) A foam positioning pad. a) 100. b) A tool for testing tomography cut levels. b) 60. c) A tool for producing a standard set of densi- c) 15. ties. 11. A Wisconsin cassette is used for testing: 19. Consistency of output can be checked by: a) mA. a) Recording how many patients are X-rayed b) Exposure time. each day. C) I 25. Clearing time refers to: 28. Quality control refers to: a) The film processing time. a) The number of good films produced over a b) The time the film should be in the wash. given period. c) The time it takes for the film to get rid of b) Making sure the processor is clean. the "cloudy look" in the fixer. c) A system which assesses and evaluates a particular activity. 26. Latitude is defined as: a) The range of exposure factors which will pro- 29. To make a noticeable change in film density the duce an acceptable image. exposure must be changed by A minimum of how many steps? b) The range of pH values of developer. a) 1 c) The amount of light produced by an inten- sifying screen. b) 3 c) 5 27. Radiolucent means: a) X-rays will pass through. 30. mAs determines: b) X-rays will not pass through. a) Penetration. c) The colour of the light given off by intensi- b) Contrast. fying screens. c) Density. QUAliTY '"'"'"'""""',.'''"•'"' WOR~mOOK 172 Glossary Acid A solution with a pH less than 7. It reacts with are few shades of grey between the lightest and blue litmus paper and turns it red. darkest areas of the image. Low contrast is when there are many more shades of grey in the image. All Beam The beam of radiation produced by the X-ray Density: radiographic Radiographic density is the tube. degree of blackening of a radiograph caused by the Bucl Characteristic curve Also known as H & D Curve or Detail: intensifying screens The name applied to a sensitometric curve. It is a plotted graph of the vari type of intensifying screen that gives better image ous densities of a step wedge image. Any variation detail, but is less responsive to radiation and there in type of film/screen, exposure or processing will fore requires a higher exposure. Commonly used for vary the shape, or Position, of the curve. extremities. Clearing time The time it takes for a film to lose the Development The chemical process of converting the cloudy appearance when placed in the fixer during latent film image into a visible one. film processing. In other words the time it takes for the unwanted film emulsion to be dissolved off by Distortion Misrepresentation of a body part outline, the fixer. in the image, due to changes in X-ray beam/body part alignment or unacceptable object film distance. Collimator A device used to control the coverage of the X-ray beam. Also known as a Light Beam Emulsion The active layer of chemical crystals sus Diaphragm CLBD). pended in a gelatine laye~ of film, which is sensitive to light and radiation. The word emulsion can also Contrast The difference between the light and dark be used to describe the radiation sensitive layer of areas of a radiograph. High contrast is when there intensifying screens. GLOSSARY 173 Exposure The amount of radiation produced from the Intensifying screens Radiation sensitive screens, X- ray tube, by a pre determined set of exposure fac placed inside a cassette, on either side of the film. tors, kV, mA, seconds. In practice the term tends to When struck by radiation the screens give off a blue be used loosely. The term "exposure" being used to or green light that has a blackening effect on the mean exposure factors". radiographic image produced. The colour of light emitted depends on the type of fluorescent materi FFD Focus/film distance. More accurately, SID (source als used. Remember that the film colour sensitivity image distance). must match the colour of light given off by the Focal range The range of focal film distances at which, screens. a grid is designed to be used. kV Kilovoltage ClOOO volts). Controls the quality Focal spot The area on the X-ray tube anode where (penetrating power) of the X-ray beam. Affects the X-rays are produced. contrast of resultant image (high kV-Iow contrast, Focussed grid Grid lines are inclined toward the low kV-high contrast). Affects intensity of radia centre of the grid, to better accommodate the tion and therefore patient dose, to a lesser extent spreading X-ray beam. CmAs has a greater effect on intensity and patient dose). Fog Radiation fogging of a film is commonly caused by scattered radiation reaching the unprocessed film. Latitude: exposure Exposure latitude is the range of Light fog is caused by unwanted white light reach exposure factors that will produce an acceptable ing the unprocessed film. Base fog is inherent fog, image. caused in film manufacture. Latitude: film Is a film emulsion characteristic that Filter: safelight A specialised, coloured glass, window, increases or reduces exposure latitude. fitted to a safelight, that enables the safe handling mA (milliampere, 1/lOOOth of an ampere) A radio of X-ray film. graphic exposure factor that controls the intensity Filter: X-ray A sheet of metal (usually aluminium) fit of radiation, influences image density and patient ted to the port of an X-ray tube to filter out the low dose. wavelength X-ray photons. mAs (milliampere-seconds) A radiographic exposure Grid A device consisting of alternate radiopaque and factor. mA x seconds. radiolucent strips. Designed to allow the primary Non-focused A grid that does not have focused grid X-rays to pass through, but absorb scattered lines. radiation. Oxidation A weakening of developer strength caused Grid ratio The ratio of the height of the radiopaque by prolonged exposure to air. (lead) strips to the distance between them (radiolu Penetration The ability of the X-ray beam to penetrate cent strips). structures. Determined by the energy of the beam Grid line The number of lead strips to the cm/inch. (controlled by kVJ. Grid cut off A reduction in grid efficiency due to pH Indicates the degree of acidity/alkalinity of a so misalignment of the X-ray beam to the grid. lution. Water is neutral and has a pH of 7. Solutions Hanger Film hanger is a stainless steel frame with with pH of less than 7 are acid. Solutions with pH more than 7 are alkaline. Developer is strongly alka clips at each corne~ for holding the film when manual processing takes place. line with a pH of about 14. Fixer is strongly acidic with a pH of about 3. Hazardous chemicals Any chemical which may have an injurious affect. Developer and fixer both fall into Phantom An object that substitutes as a patient, this category. when performing X-ray tests. The material used can be anything that is similar in density and thickness Hydrometer A sealed, weighted glass tube, with a vis to the appropriate body part. ible scale marked on i( which will float in a liquid. Used for assessing the specific gravity CS.G.J of de Potter-bucky A moving grid system designed to re veloper and fixer, the level of which is an indication duce the amount of scattered radiation reaching of the concentration. the film. Often abbreviated to "bucky". QUALITY ASSURANCE WORKBOOK 174 Primary radiation Radiation emitted from the X-ray Scattered radiation Secondary radiation which has tube that has not reached the patient, or object, been changed in direction from that of the primary being X-rayed. beam. Processing The chemical treatment of an exposed Sensitometry The study of the response of film to X-ray film that results in the production of an X-ray exposure and processing conditions. image, It involves the processes of developing, Sensitometer A standard light source that is used rinsing, fixing, washing and drying. to produce consistent step wedge images for Polyethylene foam An artificial substitute for foam sensitometric monitoring of processors. rubber. Is ideal for use as patient positioning pads. SID Source/image distance. Refers to the distance Can be easily cut to required shapes. between the source of the X-ray beam (focal spot) Puffer A rubber bulb with a nozzle for blowing dirt and the image receptor Cin conventional radiogra particles from cassettes. Often has a soft bristle phy, the film). Is a more accurate form ot focus/film brush on the end of the nozzle for the same distance CFFD). purpose. Specific gravity The weight of a substance compared Quality assurance (QA) An overall management to an equal volume of water. Specific gravity meas program to monitor the various quality control urement, using a hydrometer, can be used to meas measures being used. ure the concentration of developer and fixer. Quality control (QC) The quality control measures Stand pipe A pipe which fits into the inside of a used to evaluate performance and outcome. manual processing units wash and rinse tanks drain holes. Its height is just below the top edge of the Quality: radiograph A radiograph is said to have tank, allowing the tank to fill up and drain through good quality, when the contrast and definition are the top of the pipe. They are also found in the devel sufficient to demonstrate all required body parts oper and fixer tanks of most automatic processing well. units. Quality: X-ray beam X- ray beam quality is determined Step chart A system of exposure calculation using by its ability to penetrate objects Cthe higher the a series of exposure factor steps. Step charts are penetrating power, the higher the quality). available for kV, mA, mAs, time and FFD CSID). Radiolucent (radiotransparent) The property of a Step wedge Usually made of aluminium, is a block structure to wholly or partially allow the passage of cut to form a standard number and sized steps. Used X-rays. as a test tool for various quality control tests. Radiopaque The property of a structure to wholly or Test tool Specialised items of equipment that can be partially stop the passage of X-rays. used to evaluate X-ray or accessory equipment. Replenisher The chemical solutions that are added Thermostat A device for controlling heat output from to developer or fixer to maintain their volume and a heating unit. Used in X-ray film processing to working strength. control the temperature of developer. Replenishment Adding replenishment solutions to Thiosulphate Usually sodium thiosulphate. Is the developer or fixer to maintain their volume and fixing agent in X-ray fixing solutions. working strength. Timer: darl References Gray J E et al, Quality control in diagnostic imaging, National Radiation Laboratory, New Zealand, A glossary Aspen Publishers Inc, 1982. of physics, radiatioin protection and dosimetry in diagnostic organ imaging, International Society of Gunn C, Radiographic imaging, a practical approach, Radiographers and Radiological Technicians, 1985. Churchill Livingstone, 1988. Quinn H C, Fuch's principles of radiographic exposure HendeeW R et ai,Radiologic physics, equipment and qual control, Charles Thomas Publishers, 1985. ity control, Year Book Publishers. 1977. Radiation Protection Branch, South Australian Health ISRRT; Quality control handbook, International Society of Commission, Course notes in basic radiography, 1996. Radiographers and Radiological Technicians, 1986. Tortorici M, Concepts in medical radiographic imaging, Jenkins D, Radiographic photography and imaging Circuitry, Exposure & Quality Control, W.B.Saunders processess, MTP Press Ltd, 1980. Company, 1992. Lloyd P and Warren J, Basic radiography for general World Health Organization, Eastern Mediterranean practitioners, Techsearch Inc, 1982. Regional Office, Quality systems for medical imaging. Mcl