Report How to Read Your Exposure Report
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The Utilization of MOSFET Dosimeters for Clinical Measurements in Radiology
The Utilization of MOSFET Dosimeters for Clinical Measurements in Radiology David Hintenlang, Ph.D., DABR, FACMP Medical Physics Program Director J. Crayton Pruitt Family Department of Biomedical Engineering J. Crayton Pruitt Family Department of Biomedical Engineering Medical Physics Program Conflict of interest statement: The presenter holds no financial interest in, and has no affiliation or research support from any manufacturer or distributor of MOSFET Dosimetry systems. J. Crayton Pruitt Family Department of Biomedical Engineering Medical Physics Program The MOSFET Dosimeter • Metal oxide silicon field effect transistor • Uniquely packaged to serve as a radiation detector – developed as early as 1974 • Applications – Radiation Therapy Dose Verification – Cosmic dose monitoring on satellites – Radiology • ~ 1998 - present J. Crayton Pruitt Family Department of Biomedical Engineering Medical Physics Program Attractive features • Purely electronic dosimeter • Provides immediate dose feedback • Integrates over short periods of time • Small size and portability • Simultaneous measurements (up to 20) J. Crayton Pruitt Family Department of Biomedical Engineering Medical Physics Program Demonstrated radiology applications – Patient dose monitoring/evaluation • Radiography • Fluoroscopic and interventional procedures • CT • Mammography J. Crayton Pruitt Family Department of Biomedical Engineering Medical Physics Program Principles of operation • Ionizing radiation results in the creation of electron-hole pairs • Holes migrate and build up -
Personal Radiation Monitoring
Personal Radiation Monitoring Tim Finney 2020 Radiation monitoring Curtin staff and students who work with x-ray machines, neutron generators, or radioactive substances are monitored for exposure to ionising radiation. The objective of radiation monitoring is to ensure that existing safety procedures keep radiation exposure As Low As Reasonably Achievable (ALARA). Personal radiation monitoring badges Radiation exposure is measured using personal radiation monitoring badges. Badges contain a substance that registers how much radiation has been received. Here is the process by which a user’s radiation dose is measured: 1. The user is given a badge to wear 2. The user wears the badge for a set time period (usually three months) 3. At the end of the set time, the user returns the badge 4. The badge is sent away to be read 5. A dose report is issued. These steps are repeated until monitoring is no longer required. Badges are supplied by a personal radiation monitoring service provider. Curtin uses a service provider named Landauer. In addition to user badges, the service provider sends control badges that are kept on site in a safe place away from radiation sources. The service provider reads each badge using a process that extracts a signal from the substance contained in the badge to obtain a dose measurement. (Optically stimulated luminescence is one such process.) The dose received by the control badge is subtracted from the user badge reading to obtain the user dose during the monitoring period. Version 1.0 Uncontrolled document when printed Health and Safety Page 1 of 7 A personal radiation monitoring badge Important Radiation monitoring badges do not protect you from radiation exposure. -
Proper Use of Radiation Dose Metric Tracking for Patients Undergoing Medical Imaging Exams
Proper Use of Radiation Dose Metric Tracking for Patients Undergoing Medical Imaging Exams Frequently Asked Questions Introduction In August of 2021, the American Association of Physicists in Medicine (AAPM), the American College of Radiology (ACR), and the Health Physics Society (HPS) jointly released the following position statement advising against using information about a patient’s previous cumulative dose information from medical imaging exams to decide the appropriateness of future imaging exams. This statement was also endorsed by the Radiological Society of North America (RSNA). It is the position of the American Association of Physicists in Medicine (AAPM), the American College of Radiology (ACR), and the Health Physics Society (HPS) that the decision to perform a medical imaging exam should be based on clinical grounds, including the information available from prior imaging results, and not on the dose from prior imaging-related radiation exposures. AAPM has long advised, as recommended by the International Commission on Radiological Protection (ICRP), that justification of potential patient benefit and subsequent optimization of medical imaging exposures are the most appropriate actions to take to protect patients from unnecessary medical exposures. This is consistent with the foundational principles of radiation protection in medicine, namely that patient radiation dose limits are inappropriate for medical imaging exposures. Therefore, the AAPM recommends against using dose values, including effective dose, from a patient’s prior imaging exams for the purposes of medical decision making. Using quantities such as cumulative effective dose may, unintentionally or by institutional or regulatory policy, negatively impact medical decisions and patient care. This position statement applies to the use of metrics to longitudinally track a patient’s dose from medical radiation exposures and infer potential stochastic risk from them. -
Nuclear Radiation 1. an Atom Contains Electrons, Protons and Neutrons
Nuclear Radiation 1. An atom contains electrons, protons and neutrons. Which of these particles a) are outside the nucleus b) are uncharged c) have a negative charge d) are nucleons e) are much lighter than the others? 2. Complete the table below. Name Symbol Charge What is it? Alpha particle β -1 Gamma ray An electromagnetic wave 3. How is an ionised material different from a material that is not ionised? National 5 Physics: Waves & Radiation 1 Absorption of Radiation 1. The figure below shows a Geiger tube used to detect radiation from a radioactive source. thick lead plate 0 4 2 5 start counter stop ON OFF reset Geiger tube radioactive source The following measurements were made using the apparatus above. Counts in 300 seconds Readings Average 1 No source present 102 94 110 2 Source present at fixed distance from tube a) No lead plate present 3466 3420 3410 b) Thick lead plate present 105 109 89 c) Aluminium sheet in place of the 1834 1787 1818 thick lead sheet a) Complete the table by calculating the average readings. b) Why are the readings on each line not the same? c) What can you say from the table about the effect on the radiation of: i. The lead plate? ii. The aluminium plate? d) Why is it possible to say from the readings that: i. gamma radiation is emitted by the source? ii. alpha and beta radiation might be emitted by the source? e) What further tests could you make using this arrangement to find out whether or not the source emits alpha radiation? National 5 Physics: Waves & Radiation 2 2. -
Experiment "Gamma Dosimetry and Dose Rate Determination" Instruction for Experiment "Gamma Dosimetry and Dose Rate Determination"
TECHNICAL UNIVERSITY DRESDEN Institute of Power Engineering Training Reactor Reactor Training Course Experiment "Gamma Dosimetry and Dose Rate Determination" Instruction for Experiment "Gamma Dosimetry and Dose Rate Determination" Content: 1 .... Motivation 2..... Theoretical Background 2.1... Properties of Ionising Radiation and Interactions of Gamma Radiation 2.2. Detection of Ionising Radiation 2.3. Quantities and Units of Dosimetry 3..... Procedure of the Experiment 3.1. Commissioning and Calibration of the Dosimeter Thermo FH40G 3.2. Commissioning and Calibration of the Dosimeter Berthold LB 133-1 3.3. Commissioning and Calibration of the Dosimeter STEP RGD 27091 3.4. Setup of the Experiment 3.4.1. Measurement of Dose Rate in Various Distances from the Radiation Source 3.4.2. Measurement of Dose Rate behind Radiation Shielding 3.5. Measurement of Dose Rate at the open Reactor Channel 4..... Evaluation of Measuring Results Figures: Fig. 1: Composition of the attenuation coefficient µ of γ-radiation in lead Fig. 2: Design of an ionisation chamber Fig. 3: Classification and legal limit values of radiation protection areas Fig. 4: Setup of the experiment (issued: January 2019) - 1 - 1. Motivation The experiment aims on familiarising with the methods of calibrating different detectors for determination of the dose and the dose rate. Furthermore, the dose rate and the activity in the vicinity of an enclosed source of ionising radiation (Cs-137) will be determined taking into account the background radiation and the measurement accuracy. Additionally, the experiment focuses on the determination of the dose rate of a shielded source as well as on the calculation of the required thickness of the shielding protection layer for meeting the permissible maximum dose rate. -
Copyright by Arthur Bryan Crawford 2004
Copyright by Arthur Bryan Crawford 2004 The Dissertation Committee for Arthur Bryan Crawford Certifies that this is the approved version of the following dissertation: Evaluation of the Impact of Non -Uniform Neutron Radiation Fields on the Do se Received by Glove Box Radiation Workers Committee: Steven Biegalski, Supervisor Sheldon Landsberger John Howell Ofodike Ezekoye Sukesh Aghara Evaluation of the Impact of Non -Uniform Neutron Radiation Fields on the Dose Received by Glove Box Radiation Workers by Arthur Bryan Crawford, B.S., M.S. Dissertation Presented to the Faculty of the Graduate School of The University of Texas at Austin in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy The University of Texas at Austin December, 2004 Dedication I was born to goodly parents Harvey E. Crawford and Johnnie Lee Young Crawford Acknowledgements I would like to express my gratitude to Dr. Sheldon Landsberger for his vision in starting a distance learning program at the University of Texas at Austin and for his support and encouragement on this quest. I would like to thank my advisor, Dr. Steven Biegalski, for his support and encouragement even though the topic area was new to him. I would like to thank the members of my dissertation committee for finding the time to review this dissertation. To the staff of the Nuclear Engineering Teaching Laboratory I say thank you for your kindness and support during those brief times that I was on cam pus. A special thanks to my past and present group leaders, David Seidel, Eric McNamara, and Bill Eisele and my Division Leader, Lee McAtee, at Los Alamos National Laboratory, for their support in being allowed to use time and material resources at the Lab oratory and for financial support in the form of tuition reimbursement and travel expenses. -
Development of Chemical Dosimeters Development Of
SUDANSUDAN ACADEMYAGADEMY OFOF SCIENCES(SAS)SGIENGES(SAS) ATOMICATOMIC ENERGYEhTERGYRESEARCHESRESEARCHES COORDINATIONCOORDII\rATI ON COUNCILCOUNCIL - Development of Chemical Dosimeters A dissertation Submitted in a partial Fulfillment of the Requirement forfbr Diploma Degree in Nuclear Science (Chemistry) By FareedFadl Alla MersaniMergani SupervisorDr K.S.Adam MurchMarch 2006 J - - - CONTENTS Subject Page -I - DedicationDedication........ ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... I Acknowledgement ... '" ... ... ... ... ... ... '" ... ... ... ... '" ... '" ....... .. 11II Abstract ... ... ... '" ... ... ... '" ... ... ... ... -..... ... ... ... ... ... ..... III -I Ch-lch-1 DosimetryDosimefry - 1-1t-l IntroductionLntroduction . 1I - 1-2t-2 Principle of Dosimetry '" '" . 2 1-3l-3 DosimetryDosimefiySystems . 3J 1-3-1l-3-l primary standard dosimeters '" . 4 - 1-3-2l-3-Z Reference standard dosimeters ... .. " . 4 1-3-3L-3-3 Transfer standard dosimeters ... ... '" . 4 1-3-4t-3-4 Routine dosimeters . 5 1-4I-4 Measurement of absorbed dose . 6 1-5l-5 Calibration of DosimetryDosimetrvsystemsvstem '" . 6 1-6l-6 Transit dose effects . 8 Ch-2ch-2 Requirements of chemical dosimeters 2-12-l Introduction ... ... ... .............................................. 111l 2-2 Developing of chemical dosimeters ... ... .. ....... ... .. ..... 12t2 2-3 Classification of Dosimetry methods.methods .......................... 14l4 2-4 RequirementsRequiremsnts of ideal chemical dosimeters ,. ... 15 2-5 Types of chemical system . -
The International Commission on Radiological Protection: Historical Overview
Topical report The International Commission on Radiological Protection: Historical overview The ICRP is revising its basic recommendations by Dr H. Smith Within a few weeks of Roentgen's discovery of gamma rays; 1.5 roentgen per working week for radia- X-rays, the potential of the technique for diagnosing tion, affecting only superficial tissues; and 0.03 roentgen fractures became apparent, but acute adverse effects per working week for neutrons. (such as hair loss, erythema, and dermatitis) made hospital personnel aware of the need to avoid over- Recommendations in the 1950s exposure. Similar undesirable acute effects were By then, it was accepted that the roentgen was reported shortly after the discovery of radium and its inappropriate as a measure of exposure. In 1953, the medical applications. Notwithstanding these observa- ICRU recommended that limits of exposure should be tions, protection of staff exposed to X-rays and gamma based on consideration of the energy absorbed in tissues rays from radium was poorly co-ordinated. and introduced the rad (radiation absorbed dose) as a The British X-ray and Radium Protection Committee unit of absorbed dose (that is, energy imparted by radia- and the American Roentgen Ray Society proposed tion to a unit mass of tissue). In 1954, the ICRP general radiation protection recommendations in the introduced the rem (roentgen equivalent man) as a unit early 1920s. In 1925, at the First International Congress of absorbed dose weighted for the way different types of of Radiology, the need for quantifying exposure was radiation distribute energy in tissue (called the dose recognized. As a result, in 1928 the roentgen was equivalent in 1966). -
Cumulative Radiation Dose in Patients Admitted with Subarachnoid Hemorrhage: a Prospective PATIENT SAFETY Study Using a Self-Developing Film Badge
Cumulative Radiation Dose in Patients Admitted with Subarachnoid Hemorrhage: A Prospective PATIENT SAFETY Study Using a Self-Developing Film Badge A.C. Mamourian BACKGROUND AND PURPOSE: While considerable attention has been directed to reducing the x-ray H. Young dose of individual imaging studies, there is little information available on the cumulative dose during imaging-intensive hospitalizations. We used a radiation-sensitive badge on 12 patients admitted with M.F. Stiefel SAH to determine if this approach was feasible and to measure the extent of their x-ray exposure. MATERIALS AND METHODS: After obtaining informed consent, we assigned a badge to each of 12 patients and used it for all brain imaging studies during their ICU stay. Cumulative dose was deter- mined by quantifying exposure on the badge and correlating it with the number and type of examinations. RESULTS: The average skin dose for the 3 patients who had only diagnostic DSA without endovascular intervention was 0.4 Gy (0.2–0.6 Gy). The average skin dose of the 8 patients who had both diagnostic DSA and interventions (eg, intra-arterial treatment of vasospasm and coiling of aneurysms) was 0.9 Gy (1.8–0.4 Gy). One patient had only CT examinations. There was no effort made to include or exclude the badge in the working view during interventions. CONCLUSIONS: It is feasible to incorporate a film badge that uses a visual scale to monitor the x-ray dose into the care of hospitalized patients. Cumulative skin doses in excess of 1 Gy were not uncommon (3/12) in this group of patients with acute SAH. -
Dosimeter Comparison Chart
DOSIMETER COMPARISON CHART Instadose®+ Instadose® EPD or APD TLD Dosimeter OSL Dosimeter Dosimeter Dosimeter Dosimeter Cost $ $ $ $$$$ Photon Photon Photon Photon Photon Beta Beta Neutron DEEP - Hp(10) DEEP - Hp(10) Neutron Neutron Measurements SHALLOW - Hp(0.07) SHALLOW - Hp(0.07) DEEP - Hp(10) DEEP - Hp(10) DEEP - Hp(10) SHALLOW - Hp(0.07) SHALLOW - Hp(0.07) SHALLOW - Hp(0.07) EYE - Hp(3) EYE - Hp(3) Read Out Accumulated Accumulated Accumulated Accumulated Accumulated (On-Demand) (On-Demand) (Lab Processing) (Lab Processing) & Dose Rate Unlimited On- Demand Dose Reads Re-Calibration Required Wearer Engagement High High Low Low High Online Management Portal (Website) Provider Dependent NVLAP Highly manual Accreditation process Immediate Online Badge Reassignment Provider Dependent Archiving Dose (Wearer) Meets Legal Highly manual Dose of Record process for meeting Requirements accreditation NO Collection/ Must be collected to Redistribution meet legal dose of Required record requirements Read/View Dose Data on Your Smartphone Automatic (Calendar-set) Dose Reads Wireless Radio Transmission of USB plug-in to PC Dose Data Communication Immediate High Dose Alerts Upon Successful Communication Instadose Dosimeters use direct ion storage (DIS) TLD (Thermoluminescent OSL (Optically EPDs (Electronic Descriptions technology to measure ionizing radiation through Dosimeter) measures Stimulated Personal Dosimeter) interactions that take place between the non- ionizing radiation Luminescence or APDs (Active volatile analog memory cell, which is surrounded exposure by assessing Dosimeter) measures Personal Dosimeter) by a gas filled ion chamber with a floating gate the intensity of visible ionizing radiation makes use of a diode that creates an electric charge enabling ionized light emitted by a crystal exposure when radiation (silicon or PIN, etc.) to particles to be measured by the change in the inside the detector when energy deposited in the detect “charges” induced electric charge created. -
Site-Specific Calibration of the Hanford Personnel Neutron Dosimeter
Gw^HI0n--7 PNL-SA-24010 SITE-SPECIFIC CALIBRATION OF THE HANFORD PERSONNEL NEUTRON DOSIMETER BEC 2 7 mm A. W. Endres Q o 7- L. W. Brackenbush ° f W. V. Baumgartner B. A. Rathbone October 1994 Presented at the Fourth Conference on Radiation Protection and Dosimetry October 23-27, 1994 Orlando, Florida Prepared for the U.S. Department of Energy under Contract DE-AC06-76RLO 1830 Pacific Northwest Laboratory Richland, Washington 99352 DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsi• bility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Refer• ence herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recom• mendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. MUM1TED 4STR1BUTION Or TH« DU^- to u G£ DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best available original document. SITE-SPECIFIC CALIBRATION OF THE HANFORD PERSONNEL NEUTRON DOSIMETER A. W. Endres, L. W. Brackenbush, W. V. Baumgartner, and B. A. Rathbone Pacific Northwest Laboratory, Richland, Washington 99352 INTRODUCTION A new personnel dosimetry system, employing a standard Hanford thermo• luminescent dosimeter (TLD) and a combination dosimeter with both CR-39 nuclear track and TLD-albedo elements, is being implemented at Hanford. -
Radiation Glossary
Radiation Glossary Activity The rate of disintegration (transformation) or decay of radioactive material. The units of activity are Curie (Ci) and the Becquerel (Bq). Agreement State Any state with which the U.S. Nuclear Regulatory Commission has entered into an effective agreement under subsection 274b. of the Atomic Energy Act of 1954, as amended. Under the agreement, the state regulates the use of by-product, source, and small quantities of special nuclear material within said state. Airborne Radioactive Material Radioactive material dispersed in the air in the form of dusts, fumes, particulates, mists, vapors, or gases. ALARA Acronym for "As Low As Reasonably Achievable". Making every reasonable effort to maintain exposures to ionizing radiation as far below the dose limits as practical, consistent with the purpose for which the licensed activity is undertaken. It takes into account the state of technology, the economics of improvements in relation to state of technology, the economics of improvements in relation to benefits to the public health and safety, societal and socioeconomic considerations, and in relation to utilization of radioactive materials and licensed materials in the public interest. Alpha Particle A positively charged particle ejected spontaneously from the nuclei of some radioactive elements. It is identical to a helium nucleus, with a mass number of 4 and a charge of +2. Annual Limit on Intake (ALI) Annual intake of a given radionuclide by "Reference Man" which would result in either a committed effective dose equivalent of 5 rems or a committed dose equivalent of 50 rems to an organ or tissue. Attenuation The process by which radiation is reduced in intensity when passing through some material.