48TH YEAR, NO. 3, MAY-JUNE 1995

lOO years of radiological science

X-rays 1895-1995 Radioactivity 1896-1996 ~ l ~ ~~tt~~- rf~ RLD W -~ THE MAGAZINE OF THE WORLD HEALTH ORGANIZATION HEALTH

Our cover illustrates the advances mode in

TI-E MAGAZINEOf TI-E W01U0 t·EAHH0113ANIZATON radiological imoging over the last century. In this issue At the top, a radiograph taken by Rontgen in Editorial I 896 of the hand of his colleague, Professor Radiation medicine for all 3 von Kolliker. Centre, a computerized lOO years of tomography (CT) image of the abdomen -a Mou rice Tubiono &Gerold P. Honson radiological science technique firs t used on patients in 197 1. Radiology: a century of progress 4 Bottom, modern nuclear imoging using Pos itron Otho W. Linton &Jose ph Moro sea Emission To mograph y (PET) records the cerebral meta bolic rote of glucose in a patient with The discovery of radioactivity Alzheimer's disease. Mourice Tubiono WHO and radiation medicine 6 Gerold P. Hon son &Vlodimir Volodin Medical imaging in modern medicine 8 X· rays ~~~- 1w s Lenny K.A. Ton Radioactivily 1-"'6-1996 Profiles: Radiologists - the doctor's doctor 10 poge7 page 16 Radiographers today 10 The medical physicist 11

The basics of diagnostic imaging 12 \ .. Philip E. S. Polmer &Thure Holm Mammography: a woman's perspective 14 ~\ ~ Cori Borras ! High tech at low cost 15 Peter E. Peters &Hor st Lenzen Ultrasound imaging in developing countries 16 Hossen A. Ghorbi & M.W. Woch iro Nuclear medicine 18 Yosuhito Sosoki & Kiyoko Kusokobe Radiotheraphy: still young after almost a hundred years 20 Jeon{ loude Horiot &S uzon ne Noudy Quality assurance in radiotherapy 22 Hons Svensson &Bj orn Zockrisson Protection against radiation in medicine 24 Cesor F. Arias & Jorge J. Skvorco Radiology in the next hundred years 26 Alexander R. Morgulis The ethics of new technology 28 Sneh Bhorgovo Multidisciplinary research for health 30 Boutros G. Mo nsourion &Bruce MeA. Soyers

World Health • 48th Year, No. 3, World Health is the official illustrated mogozine of the World Heolth Articles ond photographs thot ore not copyright moy be reproduced provided Moy-J une 1995 Orgonizonon. lt oppeors six nmes o yeor in English, french , Russian ond credit is given to the Wo rld Heolth Orgonizonon. Signed articles do not Spanish, ond four nmes oyeor in Arabic ond forsi . The Arabic edinon is necessorily reflect WHO's views. The designations employed ond the IXISSN 0043·8502 ovoiloble from WHO's Regional Office for the Eastern Med iterranea n, P0 Box presentonon of moteriol published in World Health do not imply the expression Correspondence shou ld be addressed to the Editor, World Heolth Mogozine, 1517, Alexondrio 21511, Egypt. The forsi edinon is obtoinoble from the of ony opinion whatsoever on the port of the Orgonizotion concerning the World Heolth Orgonizonon, CH-121 1 Genevo 27, Switzerland, or di recMy to Pub lic Heolth Committee, Iron University Press, 85 Pork Avenue, Teheran legol stotus of ony country, territory, city or oreo or of its outhorines, or authors, whose add resses ore given ot the end of eoch article. 15875·4748, Iron. The Russian edinon con be obtained from "Meditsino" concerning the delimitation of its frontiers or boundaries. for subsuipnons see order form on poge 31. Publishing House, Pettoverigski pe r. , 6/ 8, 101 000 Moscow, Russian federonon . World Health • 48th Yeor, No. 3, Moy-June 1995 3

Editorial Radiation medicine for all Maurice Tubiana &Gerald P. Hanson

t the end of the 19th century WHO's policies and strategy. played a leading role in promoting all expectations for medical The issue of equity was clearly the rational use of radiodiagnostic Ainnovations were turned focused by radiologist Richard H. procedures, and has published rec­ towards microbiology and bio­ Chamberlain, in his seminal article ommendations on quality assurance, chemistry which were then in their "Basic radiology: a worldwide chal­ on radiation protection, and on the infancy, and no one could foresee lenge", published in 1970, which clinical indications for diagnostic new advances from physics. Yet, in pointed out that two-thirds of the imaging. The key elements for less than a decade after the discovery world's population had no access to improving equity and quality are of X-rays by Rontgen, radiology even the simplest X-ray procedures. having sufficient resources and mak­ added a new dimension to clinical When WHO adopted its strategy of ing rational and effective choices for examinations by making it possible Health for All, a remedy for this in­ their use, coupled with relevant to study hidden anatomical lesions in equity- the Basic Radiological education and training. live patients. System (BRS), now updated by the Medical imaging has achieved a Three dates stand out: in 1895, WHO Imaging System-Radiography technical level that was inconceiv­ Rontgen discovered X-rays while (WHIS-RAD)- was already being able 20 years ago, and this is only experimenting with cathode rays developed. Equity is also of the beginning. The future for radiol­ (the same week that the Lumiere paramount importance in radiation ogy is bright, with the promise of brothers introduced cinematography therapy; although over half of all computer-assistance for obtaining, in France). The reign of the image cancer patients live in the develop­ storing and transmitting images and had begun. The following year, ing world, the majority of the for the planning of radiation therapy. Becquerel in Paris di scovered developing countries do not have Telematics opens a new door to radioactivity and, in 1897, J.J. radiation therapy services. teleprocessing of images and Thomson di scovered the electron. Efforts to improve equity must telemedicine. Tomorrow any physi­ Within a decade, Rutherford, Planck not result in useless or even harmful cian, in any part of the world, will be and Einstein laid the foundations of medical procedures. WHO has able to seek on-line advice from the modern physics and its greatest specialists for applications. In retro­ the interpretation of a Science has no motherland, since human knowledge embraces the spect, one is filled with difficult image. Great "whole world.'' Louis Pasteur admiration for the cre­ hopes are now focused ative genius of these sci­ on molecular biology, entists and the rapidity biotechnology, computer with which these discov­ science and physics, and eries were made and their the world eagerly awaits applications were spread the fruits of multidisci­ throughout the world. plinary research. This issue of World By the year 2000, the Health provides an world's population is overview of today's expected to pass the technology in radiation 6000 million mark, and medicine, covering vari­ both WHO and its many ous aspects of diagnostic collaborators fervently imaging, radiation ther­ hope that vast segments apy and radiation pro­ of the population will tection. Fundamental have access to the most concepts of equity, qual­ Professor Mourice Tubiana, President, Or G. P. Hanson, Senior Scientist and essential elements of Centre Antoine Bee/ere, Paris , and Chief of Radiation Medicine, World ity and ethics are also former President of the International Health Organization. radiation medicine. • explored, as well as Society of Radiology. 4 World Health • 48th Year, No . 3, May- June 1995 Radiology: a century of progress Otha W. Linton & Joseph Marasco

ithin weeks of the German physicist, Wilhelm Conrad WRontgen, discovering the X-ray and maiUng an image of the bones of his wife's hand, in 1895, such as pneumonias, skeletal malfor­ used intensive artificial magneti c doctors all over adopted the new mations and some problems of the fields to generate radio signals discovery as a giant step forward in nervous system. from patients' bodies. Again, com­ medical care. For the first time, a Refinements in equipment, puters analysed the information to doctor could see what was happening opaque contrast materials, higher create a sophisticated image. inside a patient. The location and energy X-ray therapy sources, The centennial of Rontgen's 1895 extent of a bone fracture, a stone in radium applicators for cancer and di scovery ofX-rays finds radiologi­ the IUdney or the presence of metal, improved clinical techniques made cal techniques firmly established as as shown on an X-ray film , helped to steady progress up to and after the an essential part of medical diagnosis guide the surgeon's knife. In a mat­ Second World War. and treatment. Today, physicians ter of months, other doctors were X-ray studies improved with the who specialize in radiological applying X-rays in efforts to cure a advent of photo-timing for sharper procedures are supported in their wide range of diseases including images and electronic image intensi­ clinical work by radiobiologists and some cancers, arthritis, lupus and a fication of fluoroscopic motion physicists, dosimetrists, engineers, variety of siU n conditions which studies. Special examinations such and computer scientists. • showed improvement after exposure as mammography for the detection to X-rays. During the same early of breast cancers gained rapid years, workers in this field realized acceptance. Mr Otha W Linton is Associate Executive Director of the American College of that their own repeated exposures In the earl y 1960s, ultrasound Radiology and Executive Director of caused inflammations and even devices modified from wartime sonar Radiology Centennial/ne., 1891 Preston White Drive, Res/on, VA 22091-4397, cancers in their bodies. and radar uses began to supplement USA Or joseph Marasco is Chief of Gradually, scientists and inven­ X-rays and isotopes for the study of Medical StaH of the Forbes Regional tors like Thomas A.Edison improved organ function. Since they did not Health Centre, 2570 Haymaker Rood, Monroeville, PA 15146, USA X-ray equipment, making it more in volve ionizing radiation they were powerful, more accurate and safer to particularly attractive for studies use. Using harmless liquids which of pregnant women to detect fetal are opaque to X-rays, doctors learned abnormalities. to identify in the pictures of body The computer age made a organs the changes that indicated dramatic impact on radiology in disease. The growth of medical the early 1970s. First, computer­ applications of X-rays and natural ized tomography (for which G. ionizing radiation impelled further N. Hounsfield was awarded the advances in medicine. Early Nobel Prize in 1979) allowed diagnosis of cancers, often by X-ray cross-sectional studies, combin­ examinations, led to more successful ing thousands of bits of informa­ treatments, again involving X-rays tion to form clear images which in massive amounts to destroy the revealed new cancer cells. information to During the First World War, radiologists and doctors for the armies on both sides physicians. A relied on X-ray studies to diagnose decade later, battle fractures. In the process, many another cross­ clinicians became reliant on the X­ sectional imaging Wilhelm Conrod Rontgen, who discovered ray specialist- the radiologist- for technique, mag­ X-roys, and one of the first radiographs he diagnostic help with other problems netic resonance, mode- on image of his wife's hand World Health • 48th Year, No. 3, Moy-June 1995 s The discovery of radioactivity Maurice Tubiana

he image age began in 1895, The use of radioactive tracers has when Wilhelm Conrad Rontgen afforded biology a great leap forward Tdiscovered X-rays while experi­ because of its extraordinary sensitiv­ menting with cathode-ray tubes. ity which enables us to track small Within weeks, radiological photos numbers of atoms or molecules. It taken in Vienna, Paris and London has been a decisive tool in the birth were already enabling doctors to and development of molecular biol­ make diagnoses. ogy. As he examined one of those Alongside radiodiagnosis and pictures, in Paris in January 1896, nuclear medicine, radiotherapy forms Henri Becquerel became interested the third branch of radiology. It was in the mechanism by which X-rays born in 1896, but the discovery of are produced and particularly in its radium in 1903 gave it a new dimen­ links with fluorescence. Two months sion. The progress made over the later he showed that a natural ele­ past hundred years has confirmed it Henri Becquerel discovered radioactivity of the ment, uranium, spontaneously emits age of 44 when he was examining Rontgen's as one of the principal weapons for rays closely resembling X-rays. It is early X-ray images. treating cancer. In any effective from this discovery of natural radio­ cancer control programme today, activity that emerged, first radium­ radiotherapy -alone or in association isolated by Pierre and Marie Curie in with surgery or chemotherapy- is 1898 -and then its medical applica­ medicine was to be rapidly built up needed for over half of the patients tions, greater understanding of the between 1935 and 1939, and suffering from cancer. structure of the atom, radiochemistry, especially after 1945. Radiobiology and radioprotection artificial radioactive isotopes and­ also deserve a mention. From the eventually- atomic energy. The first years of this century, it was discovery of the electron in 1897 by Using trace elements known that ionizing radiation can Joseph John Thomson laid the basis cause cancer and leukaemia. for modern electronics and specifi­ From 1948 onwards, patients were Between 1920 and 1939, the fre­ cally for its medical applications. being injected with artificial radio­ quency of leukaemia among radiol­ Thus, within the space of three isotopes to see what became of them, ogists was ten times higher than years, three discoveries- of X-rays, thus permitting the study of their among other physicians. In 1934, we radioactivity and electronics - were topographical spread within the first began to understand the relation made which were to dominate the body. For instance, by examining between the dose and the risk of 20th century. In 1934, the discovery what happens to radioactive iodine cancer; a number of simple rules of of artificial radioactivity by Irene and introduced into the thyroid, we can radiation protection were laid down Frederic Joliot-Curie gave a new measure the radioactivity of this and a maximum permissible dose boost to the medical applications of gland and observe its morphology. limit was introduced. Although this radioactivity. We learnt how to Subsequently scintigraphy and the was relatively high compared with manufacture radioactive isotopes scintigraphic camera provided high the levels enforced today, those from most of the natural elements quality images which can be recommendations were sufficient to and, thanks to the radiation that they analysed to assess the functions of check the excess of leukaemia in emit, we could track them or the different parts of a single organ. radiologists; since 1950, that molecules into which they had been Since 1970, scintigraphy has become frequency is no higher among introduced in the interior of the an essential tool for exploring the radiologists than among other organism. This method of using functioning of a great number of doctors. • trace elements had been pioneered by organs and associated tissues. Georg von Hevesy with natural Thanks to the positron camera, radioisotopes since 1913. Antoine tomoscintigraphy and functional Lacassagne discovered the principle imaging, nuclear medicine is today of autoradiography in 1922. It was one of the most dynamic branches of Professor Maurice Tubiana is President of the Centre Antoine Bee/ere, 45, rue des Saints· on these foundations that nuclear medical imaging. Peres, 75006 Paris, France. 6 World Health • 48th Year, No. 3, May- June 1995 WHO and radiation medicine Gerald P. Hanson &Vladimir Volodin

uring the first decade of its ceptable, the primary health care nation most likely to be needed by existence, WHO initiated approach was imperative. In 1981, small rural and district hospitals Dactivities in radiation medicine the World Health Assembly unani­ throughout the developing world are and also responded to public appre­ mously adopted a global strategy and those of the chest, skeleton (incl ud­ hension about radiation hazards. Health for All became the overall ing the head), abdomen and soft Among WHO's early published goal of WHO. tissue. reports were Effects of radiation on Radiological services for diagno­ The fundamental objective of human heredity (1957), and Post­ sis, therapy and prevention (protec­ WHO's programme in radiation graduate training in the public tion against risks) are designed to medicine is to increase access to health aspects of nuclear energy serve all the population rather than diagnostic and therapeutic radiologi­ (1958). Scientific interest in radia­ concentrating on a specific group or cal services while maintaining their tion risk and laboratory procedures disease. Logically, demographic and quality and safety. There are three gradually took into account public epidemiological considerations must major areas. health concern about the provision of guide the establishment of priorities. • Diagnostic imaging is involved essential radiological services for For example, as the proportion of in many crucial medical deci­ diagnosis and therapy. Today hardly elderly persons increases, the inci­ sions, but only about one-third of a hospital of any size is built without dence of chronic and degenerative the world's population has access having a diagnostic imaging service diseases and diseases related to to even the most essential ser­ or a plan for one. industrialization and urbanization are vices and the quality is often expected to increase. Accidents, questionable. injuries and violence are becoming a • Radiation therapy is required for Services for all serious cause of mortality and mor­ more than one-half of all cancer bidity in developing countries and in patients, yet the necessary tech­ A substantial change in WHO's some places now rank among the nology for treatment, including programme emphasis was the result first five causes of death. accurate dose delivery, is often of the International Conference on Based upon the epidemiological lacking. Primary Health Care, held in Alma­ situation and the expected health care • Radiation protection and safety Ata in 1978. As the health status of a that will be needed for most of the are absolutely essential, because large portion of the world was unac- population, the types of X-ray exami- more than 95 % of all man-made ionizing radiation exposures are caused by medical use.

Diagnostic imaging Since some two-thirds of the world's population lack any diagnostic imag­ ing services, WHO concentrated on developing the Basic Radiological System (WHO-BRS) during the period 1975-85, and recently pre­ pared its updated version, the WHO Imaging System-Radiography (WHIS-RAD). Currently the WHO­ specified equipment is produced by several leading manufacturers and about 1000 units are install ed in some 60 countries. Efforts are also being made by WHO, in collabora­ A radiographer examines an X-ray obtained by using the Basic Radiological System in Kenya. tion with the United Nations World Health • 48th Year, No. 3, May-June 1995 7

Industrial Development Organization Atomic Energy Agency (IAEA) have WHO and several other inter­ (UNIDO), to promote the manufac­ initiated a number of activities for national organizations collaborated ture of these X-ray machines in improving cancer care, directed in preparing the new Basic safety developing countries. toward the needs and requests of standards for radiation protection in In recent years, ultrasound has Member States. These include a industry, medicine and agriculture, merited high priority because of its global network of Secondary and a revised edition of the Manual value in small hospitals once there Standard Radiation Dosimetry on radiation protection in hospitals are properly trained staff. Attention Laboratories to improve the accuracy and general practice, covering is also being given to intermediate­ of radiation dosage, as well as train­ all aspects of the use of ionizing level or general-purpose radiology ing courses in radiotherapy in vari­ radiation in medicine is now being for referral hospitals beyond the level ous parts of the world. The global prepared. of basic radiology. Guidance is network now includes 73 laborato­ provided on selecting appropriate ries in 56 countries, 43 of which are equipment, training the staff, intro­ developing countries. The future ducing quality assurance programmes, and ensuring Within almost any health radiological protection. care system, there is a When governments re­ spectrum of imaging needs quest it, WHO provides and the associated equip­ technical cooperation for ment which ranges from specialized radiology the most essential, such as services in large urban or the WHO-BRS or WHIS­ university hospitals. RAD, to the most com­ Quality assurance, plex, such as computerized radiation protection and tomography or magnetic the rational use of radia­ resonance imaging. Issues tion- including methods to be resolved are the for saving resources, clinical decision-making improving quality, and process through which reducing doses to patients diagnostic imaging exami­ -are key elements in the nations are selected as well effort to make sure that as the optimum mixture of equal access does not diagnostic imaging modal­ result in wasteful health ities. care. In parts of the world WHO has convened a such as Africa and South­ number of scientific The radiographer prepares a young boy for a chest X-ray in Colombia. East Asia, where the major meetings and issued clear issue is the shortage of recommendations on the clinical personnel and equipment, efforts indications for major diagnostic should concentrate on training X-ray investigations, including when nationals in their own countries radiological investigations are not Radiation protection using the equipment available. justified. This guidance can be found Where radiological imaging and in Effective choices for diagnostic WHO has also been concentrating on radiotherapy have been available for imaging in clinical practice, pub­ matters of radiation protection during many years, as in Latin America, lished in 1990. its efforts to extend diagnostic and international cooperative efforts therapeutic coverage, thereby ensur­ should be directed towards improv­ ing that the provision of these health ing quality in the delivery of Radiation therapy benefits will not cause harm. It is services. Likewise, the quality of crucial to incorporate radiation radiation protection services will WHO's strategy for extending radia­ protection concepts in the planning have to be improved in some tion therapy services concentrates on of medical diagnostic and therapeutic countries and these services must be those cancers affecting large num­ services, and to promote the coordi­ started from zero in others. • bers of people, which are amenable nation of quality assurance and to such treatment. Radiation therapy, radiation protection procedures. alone or in conjunction with surgery WHO provides technical cooperation Or Gerald P. Hanson is Senior Scientist and or chemotherapy, is required for Chief and Or Vladimir Volodin is Medical to countries for their national radio­ Officer, Radiation Medicine, World Health more than half of all cancer patients. logical protection services or to help Organization, 121 I Geneva 27, WHO and the International establish such services. Switzerland. 8 World Health • 48th Year, No . 3, Moy-June 1995 Medical imaging in modern medicine Lenny K.A. Tan

The next hundred years will no doubt produce further technical advances in radiology. But it will still take the trained eye of the physician radiologist to apply this technology to each patient's health problems. A surgical intervention carried out under X-roy control.

ooner or later, your doctor is beam, our bodies have four densities. the lining of the digestive system. going to look at his clinical notes Bones are the densest and block the Other opaque liquids can be injected 5and tell you "we need to make most X-rays, while the air space in into blood vessels to look for narrow­ an X-ray examination to find out our lungs lets most of them pass ing or blockages which contribute to what is causing your problem". In through. The water density of the strokes or heart attacks. recent years, the doctor has been intestines and the fat densities of the using newer imaging techniques - muscles fall somewhere in between. "isotope study", "ultrasound", The radiologist or other physician Radioactive scanning "computerized tomography" or must become proficient in recogniz­ "magnetic resonance image"; all ing an abnormal shadow indicative Today's radiologist has other choices these are part of the modern of disease conditions. Thus, many of imaging techniques besides X-ray discipline of radiology, which forms of cancer are denser on X-rays studies. Many health problems can marks its lOOth year in 1995 . than the normal tissues surrounding be detected and diagnosed by using In many countries, medical imag­ them. If the radiologist is interested trace amounts of radioactive sub­ ing is as common, as simple and as in movement, a device called a stances, for instance an isotope called safe as a doctor's use of a thermom­ fluoroscope allows real-time viewing technetium 99m. The patient swal­ eter or stethoscope, and it extends a of the beating of the heart, the puls­ lows or is injected with a tiny amount doctor's powers of observation ing of blood through an artery in the of technetium in a harmless chemical beyond what he or she can see or head, or the flushing of urine from which concentrates in the organ to be touch or hear. The risk involved in a the kidneys. studied. A scintillation detector medically justified and properly If the radiologist wants to look at called a gamma camera records the conducted X-ray examination is the inside of an organ system, the pattern of radiation taken up by that usually so low that it is far out­ patient is given a liquid such as organ. If a cancer is present in the weighed by the expected medical barium sulfate which is opaque to liver, for example, the isotope scan benefit. X-rays. The radiologist can watch it pattern is abnormal because the Such images depict the passage of flow through the oesophagus, into cancer absorbs the isotope differently X-rays through our bodies and their the stomach and ultimately the from normal tissue. partial absorption by different body intestines, revealing narrowings, With computerized tomography, organs and structures. To an X-ray blockages, ulcers or even cancers in the radiologist uses a complex World Health • 48th Year, No. 3, May-June 1995 9 machine involving multipleX-ray ideal for examining the status of There are a few circumstances sources and absorption detectors. unborn babies or in other circum­ where an encounter with a radiology The resulting image is a cross­ stances where a patient's exposure to procedure does not depend on a sectional view, a bloodless slice, large amounts of X-rays might be doctor's referral. These are usually through the body. By viewing a hazardous. for population screening. The most series of slices at close intervals, the commonplace example is the use of radiologist can get a complete pro­ chest X-rays to detect tuberculosis in file of a body organ. A still newer Special skills needed people who have no symptoms. In cross-sectional imaging technique, some countries, women over the age magnetic resonance (MR), uses For most X-ray, ultrasound, and of 40 are urged to get regular breast multiple image detectors and a nuclear medicine examinations, a X-ray examinations- mammograms computer integration programme. technologist works with the patient -for the detection of breast cancer. Instead of X-rays, it relies upon a to obtain still images for study by a A hundred years of X-ray science strong magnetic field to generate radiologist. The radiologist usually have made medical imaging a vital radio signals from the atoms of our participates in motion studies. But a part of modern medicine. The next bodies. As with X-ray studies, radiologist or another specially hundred years will no doubt produce contrast liquids can be given to the trained physician is always involved still further technical advances in patient to enhance visual distinctions in interventional radiology- proce­ radiology. But it will still take the in complex body structures. dures in which fluoroscopic studies trained eye and educated mind of the For ultrasound examinations, a are made of the motion of blood physician radiologist to apply this pulsed beam of sound above the vessels or other body channels. In technology to each patient's health audible range is directed into a most medical systems, a patient's problems. • patient's body. Various body struc­ own doctor decides if an imaging tures reflect the sound beam differ­ procedure is needed and refers the ently. These reflections make a patient to a radiologist. The referral pattern on a screen showing yet may be to a hospital X-ray depart­ another version of anatomy and ment, a private office or a clinic. Professor Lenny K.A. Tan is Dean of the Faculty motion. After more than 30 years of Sometimes, the patient's physician of Medicine at the National University of Singapore, 5 Lower Kent Ridge Road, use, no adverse health effects have may have his or her own X-ray equip­ Singapore 051 I, and President of the been detected, making ultrasound ment and perform the examination. International Society of Radiology.

Use of radiation in medicine: some historical notes Rontgen 's d iscovery of X-rays occurred in November 1895, and the results of his pioneering work were reported to the Society for Physical Medicine of Wurzburg the following month. What is perhaps less well known is that, as early as 1 8 Ja nuary 1 896, a distinguished Hungarian physician , Endre Hogyes, published a paper in a Hungarian medical journal , OrvosiHetilap, in which he suggested that the new technology might have potential applications in medicine. His paper, entitled "Photography of the skeleton th rough the body using Rontgen 's method ", is illustrated by a se ries of remarka ble radiographs, including one showing the skeleton of a frog (see alongside) . This photograph seems never to have been reproduced after the orig ina l 1896 publication. The first rad iological journal, the Archives of Clinical Skiagraphy, w as launched in London in April 1896, wh ile in the follow ing year the X-ray Society (later renamed the Rontgen Society) was established , also in London. Finally, the era of radiation protection legislation appears to have begun in October 1899, w hen the Provincial Government of Lower Austria issued a Decree (No. 8831 of 21 October 1899) imposing str ingent conditions governing the use of X-rays for d iagnostic or therapeutic pu rposes- a harbinger of the ma ssive, and complex, regulatory standards that were to follow much later in many other countries.

Contributed by Sev S. Fluss, Adviser on Health Legislation to Director, Division of Publishing, Language and Library SeNices, WHO, Geneva, Switzerland. 10 World Health • 48th Yeor, No. 3, Moy-J une 1995 • •

diagnosing and treating many of the diseases that afflict Radiologists - the doctors' doctors mankind. Physicians everywhere are discovering that the radiological sciences- and their practitioners, the radiol­ ogists- are their staunch allies in the quest for better health. •

Contributed by Professor An ne G. Osborn, University of Utah Medical Center, 50 North Medical Drive, Soft Lake City, UT 84132, USA She is Chairman of the International Commission on Radiological Education.

Radiographers today

Radiologists studying on echogrom.

o, radiologists don't repair radios! Since Rontgen discovered the X-ray 100 years ago, the term N"radiology" has been used to denote the medical uses of radiation and "radiologist" to designate the med­ ical doctor who specializes in radiological sciences. First and foremost, radiologists are physicians of more than one kind. Diagnostic radiologists diagnose everything from fractures and tuberculosis to brain tumours and complications of pregnancy. Therapeutic radiologists use radiation to treat- and often cure­ Students taking notes at the Radiological Technologists' Education Centre diseases. And nuclear medicine denotes the medical uses in japan. of special radioactive isotopes in both the diagnosis and treatment of diseases. he job of the radiographer has changed dramatically Radiologists are also consultants and have occasion­ in the past few decades. The early technicians who ally been described as "the doctor's doctor". As rapid Tmade photographic records (radiographs) of anatom­ advances in medical imaging have provided radiologists ical structures have now, in the industrialized world, with unparalleled capabilities to examine the human become "radiological technologists" (RTs) involved in body without the discomfort and risk associated with complex functional studies using computer images. surgical exploration, other physicians have increasingly Radiological technologists also work in radiotherapy turned to them for assistance in diagnosis. - treatment by the application of radiation from outside Accurate, highly detailed pictures of the body from the body or using radioisotopes - and also hyperthermia top to bottom can now be obtained quickly and non­ using non-ionizing radiation (microwaves or ultrasound). invasively. In fact, radiology is itself an outmoded term While radiation and radioisotopes are extremely benefi­ since many new medical imaging techniques don 't use cial tools for medicine, they can be very harmful if mis­ X-rays at all. Various forms of electromagnetic energy used. RTs consequently have to learn to pay careful can be employed to diagnose and treat a broad spectrum attention to the protection of the patient and safety of diseases. For example, ultrasound studies use sound control. waves to peer inside the body. A relatively new tech­ Over the years the RT has evolved into an indepen­ nique, magnetic resonance imaging (MRI), uses special dent profession, part of a closely integrated team of radiofrequency pulses. MRI can provide dynamic im­ medical specialists, physicists, nurses and others. Three­ ages of the beating heart as well as exquisitely detailed year courses are now available in many countries, provid­ studies of such tiny structures as the inner ear. ing a solid basis for developing skills and offering vital Although buying and maintaining equipment is hospital experience as a compulsory part of training. expensive, as is the training of technologists and radiol­ Young people today wishing to apply should have a good ogists in large areas of the world, medical imaging preparation in basic science and a sensitivity to the needs research is providing increasingly accurate ways of of their fellow human beings. A genuine wish to be of World Health • 48th Yea r, No. 3, Moy-J une 1995 11 • service is a prerequisite and good communication skills resonance imaging), radioactively labelled pharmaceuti­ lead to opportunities in teaching and management as well cals (radionuclide imaging), minute electrical impulses as research. (applied potential tomography), ultrasound (ultrasonic The Japan Association of Radiological Technologists imaging) or lasers (laser doppler imaging), whichever is Education Centre (JARTEC), a WHO Collaborating most appropriate. To examine the functioning of various Centre for the Training of Medical Radiological parts through physiological measurements (often of tiny Technologists, is operated by the Japan Association of electrical signals), methods that are largely noninvasive Radiological Technologists, and accepts students from have been developed by medical physics departments in overseas for training each year. It also financially assists collaboration with colleagues in such diverse fields as radiological technologists in other countries to acquire cardiology, audiology, ophthalmology, neurology and new technology, and promotes academic and technologi­ urology. cal research and development as well as continuing Medical physics departments have made major con­ education. tributions over many years to treatment planning and International understanding of the rapid changes in dosimetry, and they have been concerned with the opera­ this profession is helped by the ex perience of individual tion and maintenance of equipment, devising improved national societies. They help each other by producing procedures, and ensuring protection against radiation. journals and organizing conferences, often in association Other important areas of collaboration include the use of with the International Society of Radiographers and ultraviolet radiation for skin disorders, and lasers for Radiological Technologists (ISRRT) which is a non­ surgery. For internal treatment, the mechanical engi­ governmental organization in official relations with neering, electronic engineering and computing expertise WHO . • of multidisciplinary medical physics teams has been exploited in developing artificial heart valves, limbs and organs. The same experti se has also produced ingenious, Contributed by Or Minoru Nokomuro, Director of the japan Association relatively low-cost, technical aids for handicapped of Radiological Technologists Education Centre UARTEC) and the WHO people, tailored to individual needs for everyday living. Collaborating Centre for the Training of Medical Radiological Technologists, I 00 I Kishioko , Suzuko City, Mie Prefecture 51 0{)2, Medical physics departments provide a very cost­ japan, and Miss Morion Frank , Radiographer, 16 Heron Court, 63 effective base for the cross-fertilization of expertise in Lancaster Gate, London W2 3NJ. England Or Nokomura is also science and technology, which is essential to meet the President of the International Society of Radiographers and Radiological needs of patients and their doctors. • Technologists.

Contributed by Professor Keith Boddy, President of the International Organisation for Medical Physics (IOMP) , and Head of the Regional The medical physicist Medical Physics Deportment, Newcastle General Hospital, Newcastle upon Tyne NE4 6BE, England he human body can be regarded as a machine controlled by the world's most sophi sticated micro­ Tcomputer, the brain, which is about the size of a grapefruit and largely self-programmable. The machine is largely waterproof and entirely rustproof, self­ propelling in any direction and equipped with a pair of sensitive manipulators. Control is effected, with auto­ matic feedback, through self-adjusting binoculars and by auditory, olfactory and tactile signals. The machine is powered by a wide variety of fuels via a single multi­ purpose carburettor system. It can self-replicate at minimal cost and, although no guarantee is provided, has an expected lifetime of about 70 years. To some extent, it is even self-repairing. To view the inside of the machine without causing pain, medical physicists, with colleagues in radiology and nuclear medicine, have developed a variety of tech­ niques to image the internal organs from practically any angle. These methods make use of X-rays (computer­ A medical physicist runs a test on a linear accelerator before putting it ized tomography scanning), magnetic fields (magnetic into clinical seNice. 12 World Health • 48th Year, No. 3, May-June 1995 The basics of diagnostic •1mag1ng • Philip E.S. Palmer & Thure Holm

A patient is brought too radiological centre in Sweden. For a little girl with a possible broken arm, the first problem is to reach the Kroy centre.

rom first aid to primary care to but in the last 50 years many other • the quality of the images must be first-referral hospital, doctors imaging methods have been devel­ excellent; Fneed to know more about their oped. Of these, ultrasound is the • the equipment must be safe for patients, not only judging from the most useful, most often used, and both patients and personnel; outside but finding out what is going least harmful. Together with radiog­ • the equipment must be easy to on inside as well. People visit doc­ raphy, ultrasonography is now firmly install and use; tors for very much the same reasons, established as a basic aid for diag­ • the equipment must be reliable whether they are in big cities, small nostic investigations. and usable even when the electri­ towns or out in the country. Often Ultrasound cannot image frac­ cal supply and other services are they have been injured and accurate tures or other skeletal diseases, nor substandard; assessment to exclude a skeletal can it image the lungs. Therefore, • the equipment should need mini­ fracture presents a major clinical unless most of the patients are preg­ mal maintenance care. need for diagnostic imaging. Or they nant, the most essential requirement have some illness, in which case is an X-ray unit. However, in its own It is really not difficult to satisfy much can be learnt with a stetho­ way, ultrasound is equally important these basic requirements because scope, but a radiograph could tell and not just for obstetrics. It is better today's imaging equipment can more. The third major need for at imaging the pelvic contents, the make use of advanced and sophisti­ diagnostic imaging arises in preg­ liver, pancreas, spleen and kidneys, cated designs to produce something nancy: if either the mother or the the thyroid and the neonatal head. easy to use; after all, a pocket calcu­ baby appears not to be progressing as There is really no valid choice be­ lator is simple to use but it contains expected, the doctor or midwife will tween the two. To provide good some very advanced electronic want to see an ultrasound scan. patient care, doctors need the help of wizardry. Thus the basic equipment of any both X-rays and ultrasound. Most X-ray equipment has many imaging department is self-evident: It is difficult to choose equipment technical parameters which can be a good general X-ray set and a because there are so many alterna­ altered when used with patients. general purpose ultrasound unit. tives but WHO has, with the advice This may reduce the image quality For years after Rontgen's discovery, of a group of experts, laid down and increase the radiation dose to the "diagnostic imaging" meant only some basic criteria to simplify the patient and often to the staff as well. "radiography", the use of X -rays to choices. To counteract this risk, the WHO obtain a radiograph (an X-ray film), Five principles must be followed: Imaging System- Radiography World Health • 48th Year, No. 3, May June 1995 13

analysis. The WHO imaging system should be Specifications made available to all people every­ are also available where, providing optimum help for darkroom whenever they are ill. • equipment, and manuals are published by WHO in many Or Philip E.S. Palmer is Emeritus Professor of languages to Radiology, University of California, 821 Miller Drive, Davis, CA 95616, USA. Or Thure explain radio­ Holm is Senior Consultant Radiologist at the graphic technique, Department of Radiology, Lund University film processing in Hospital, and Chief of the Basic Radiology the darkroom, and Section of the WHO Collaborating Centre for General and Continuing Radiologic Education, X-ray film inter­ Roentgen St Lars, S-22009 Lund, Sweden. pretation. The WHO Manual of Whether obtained by X-ray or by ultrasound, the images will help to diagnostic ultra­ make the correct diagnosis. sound has just ''I didn't think, been published I investigated" (WHIS-RAD) requires that most of this year. This was the answer Rontgen these variables are fixed at the opti­ Many hospital administrators and gave when asked what his mum setting. This has not reduced doctors worry about the dangers of thoughts were when he the flexibility of the design, which radiation. However, provided the discovered X-rays. A thorough can easily provide over 100 standard room used for X-ray examinations is researcher and a brilliant radiographic projections, but it has large enough (minimum 3.5 m x experimentalist, he believed that made the units very safe. In fact the 4.5 m) and the staff stand behind the science did not belong only to radiation dose received on the skin mandatory protective screen or wall sc ientists. Shortly after the "new of the patient is usually half that during each exposure, there is negli­ kind of ra ys" were first reported, received from more common X-ray gible radiation risk to the personnel. a ma jor German electrotechnical equipment. As already noted above, dosage is company tri ed to negoti a te a Several WHO-specified X-ray low because of an optimized exami­ copyright deal with him on al l his units have been thoroughly tested in nation technique, resulting in very future discoveries and inventions. professional use at university hospi­ few retakes. As far as is currently Rontgen refused, and thus tals in Sweden, England and the known, ultrasound poses no risk for forfe ited the chance of making Netherlands. Others have been patient or staff. huge profits. He considered his equally well tested in small govern­ WHO has specified complete discoveries belonged to human ity ment or mission hospitals in many systems for imaging with X-rays and and should not be hampered by parts of the world, often operated by ultrasound, and can provide expert patents, licences, or monopoly staff who have no formal radio­ guidance on the design and layout of contracts . He did not even secure graphic qualifications. The results X-ray rooms and the requirements th e copyright on his first X-ra y have been equally good, and doctors for radiation safety. The equipment pictures. He also rej ected an everywhere have been pleased with meeting these specifications is avail­ offered ti tl e that would have made the images they have been given for able from various manufacturers. him part of the German nobility, and donated to the Un iversity of The WHO lmaging System - Radiography (WHIS-RAD) Wurzburg the money he rece ived fr om the Nobel Pr ize conferred WHIS-RAD is designed to be used in any X-ray department by fully tra ined on him in 1901 . His generosity radiographers or by radiographer's assistants under proper supervision. of spirit certa inly contributed to lt is intended for radiography of standing, sitting and lying patients. The the rapid spread of the new image quality can be as good as th ose in a teaching hospital. . . discovery and paved the w ay for Optimum imaging conditions are built into the system , mclud1ng fixed the extraordinary developmen ts im aging geometry, using the pendulum principle for angulation of the in imaging techniques that w ere X-ray beam, and a permanently centred anti-scatter grid. to follow. High-tech X- ra y generators are used, using multipulse inverter technology and energy storage in batteries, which results in shortest Adapted from: The Health Physics Society possible exposure times and very reproducible X-ray tube output. The Centennial Calendar (1994), and batteries can be powered from a 230 volt, 10 ampere AC wall outlet or 0. Glasser, Wilhelm Conrad Roentgen from a solar panel. A single-phase X-ra y generator, directly connected to and the early history of the Roentgen rays, London, ). Bale, Sons & Danielsson, a common 50/ 60Hz electric wall outlet, cannot be used. 1933. 14 World Health • 48th Year, No. 3, Moy-June 1995 Mammography: a woman's perspective• Cari Borras

reast cancer is particularly raises a number of important ques­ dreaded because of the mutila­ tions about how they should be Btion it causes. In the USA one used. For instance, are these means woman in eight develops it, in the available in all countries? Are the United Kingdom one in twelve. It is physicians who interpret mammo­ also becoming more common in grams adequately trained? How is developing countries, as many of the the quality of the equipment infectious and parasitic diseases assured? Who makes sure it is gradually come under control. What being properly used? Are women is to be done about it? At present the aware that they should have a best answer is to detect it early so periodic breast examination? Do that it can be treated with minimal they practise self-examination? surgery, which gives the best cosmet­ ic results and the least psychological trauma. If the cancer is discovered in the "preclinical" stage, the proba­ bility of cure lasting for at least 20 years is 93 %. A mammogram, obtained with a special At present, the only way to make machine, gives the necessary diagnostic a reliable early diagnosis of breast information. cancer is with mammography, a specialized radiographic technique for studying the mammary gland. screening programme may be the Because the breast does not contain least expensive screening pro­ high density material, such as bones, gramme there is, when one com­ it is difficult to radiograph. An pares the cost per mammogram image produced with the normal with the number of years of life technique for a chest X-ray, for saved. In terms of action, perhaps example, will show a uniform mass women should start by demanding without any detail. Much better a review of breast cancer incidence results can be obtained with a special in their community and of the X-ray machine using a mammo­ health services needed to control graphic technique (see photos). it. Such services must include To detect small lesions, high public information and education, contrast and resolution are needed. as well as diagnosis and treatment. As in photography, they can be Radiograph of a woman's breast using an ordinary X-ray machine does not provide the necessary • obtained with slow film, which information . requires a longer exposure. This has to be balanced exactly against the If there is no quality assurance for Or Cari Borras is Regional Adviser, need to keep the radiation dose to a existing mammography services, Radiological Health, World Health minimum. With the right equipment perhaps the patients themselves Organization Regional Office for the Americas/Pan American Health Organization, and procedures, a sufficiently clear should demand it. Private patients 525, 23rd Street N. W., Washington, DC and detailed mammogram can be can do this very easily, but what 20037, USA produced. Then, equally impor­ choice do the others have? What tantly, it must be interpreted by a should women do to assert their right qualified specialist. to survive and to do so with minimal The fact that the technical means surgery? One strong argument they of controlling breast cancer exist can use is that a mammography World Health • 48th Yeor, No. 3, May-June 1995 15 High tech at low cost Peter E. Peters &Horst Lenzen

edical imaging has come a long way from the machine Mthat made the first image of Bertha Rontgen's hand to the highly sophisticated computerized devices fashion, ultrasound imaging devices High tech at low cost is therefore available today. Rontgen refused to have been developed which can be possible and, most importantly, low patent his discoveries and inventions, used under demanding environmen­ cost does not mean low quality. The though invited to do so, on the tal conditions such as high tempera­ current very high prices for modem grounds that such things belonged to tures, high humidity, and erratic imaging equipment can easily be cut humanity, whose use of them should power supply. Even the most sophis­ if minor limitations in speed are not be restricted. This noble attitude ticated imaging technique, computer­ accepted. If one considers the time certainly contributed to the rapid ized tomography, is now approaching necessary to transport a patient to the development of X -ray technology, global distribution. Recent models nearest major city where one of although subsequently a large num­ do not require special power lines or these devices is available, it may be ber of patents were filed by others for air-conditioning, and can complete a feasible and more economical to improvements of his technique. The study even when there is a total have a somewhat slower imaging improvements have been accompa­ black-out. Their battery back-up device in several district-level nied by rising costs. A hundred years system can be recharged with solar hospitals. • ago, Rontgen complained to his energy collectors when power cuts glassblower about the high price and are prolonged. The latest devices use short lifespan of the X-ray tubes he strong magnetic fields to generate used, but at that time they were about images. The equipment is still ex­ Professor Peter E. Peters is Chairman of the 1000 times cheaper than they are tremely expensive both to set up and Institute of Clinical Radiology, Albert· today. to maintain, but affordable magnetic Schweitzer·Strasse 33, 48149 Munster, The costs are even higher for the Germany, and Mr Hors! Lenzen is Head of the resonance imaging machines should Physics Laboratory, Department of Clinical advanced types of medical imaging, be on the market before the turn of Radiology, University of Munster Medical in which a number of thin cross­ the century. School, Munster, Germany. sectional images are taken rather than one single X-ray picture. This technique requires the use of com­ puters, which need a stable power supply and often must be kept in air­ conditioned rooms. These needs cannot be met in many parts of the world, and thus millions of people are excluded from these benefits. But things are getting better, and high tech at low cost is no longer a dream. Mainly because of mass produc­ tion, computers are becoming cheaper, more powerful, and less sensitive to adverse environmental conditions. Television sets and transistor radios were once rare and expensive but are now found in almost every corner of the world. Conventional X-ray examination became widely available through the development of rugged, high-quality, A magnetic resonance imaging scanner. This equipment is still extremely expensive to install and low-cost equipment. In a similar maintain, but affordable machines should be on the market by th e turn of the century. 16 World Health • 47th Year, No. 6, November-December 1994 Ultrasound imaging in developin! Hassen A. Gharbi & M. W. Wachira

Despite considerable and growing worldwide investment in diagnostic imaging technology, about two-thirds of the population in developing countries do not have access to even the most basic X·ray or ultrasound diagnostic services.

ince the first attempts in 1954 to use ultrasound waves in medi­ Scine, this technique has devel­ oped with spectacular rapidity. It is now a well-established and widely recognized diagnostic imaging discipline which enjoys increasing popularity among clinicians. An Draining a liver abscess under ultrasound control in Tunisia. important reason for its success is vessels and other organs and tissues. shown that 95 % of cases of hydati­ that ultrasound equipment is smaller It can also give precise answers to dosis in the liver and abdomen were and less expensive than other imag­ many of the urgent questions which diagnosed by ultrasound. The other ing devices and does not have may arise during pregnancy. The 5% were diagnosed with other special requirements for premises introduction in clinical practice of imaging modalities such as conven­ and installation. The market for Doppler and colour Doppler tech­ tional radiology or computerized ultrasound imaging is doubling niques has made it possible to ob­ tomography (CT). Ultrasound has approximately every 5 years and serve fetal cardiac activity and to also been helpful in the treatment of today represents about 20% of the visualize blood flow within arteries hydatid cysts. In 1986 Dr M. world market in diagnostic imaging. and veins. Gargouzi, of Tunisia, developed a However, as ultrasound cannot scan In many developing countries, new technique which he called bones or the lungs, X-rays must ultrasound may also have an impor­ "PAIR": puncturing of the cyst remain the first choice for diagnostic tant application in diagnosis and under ultrasound control, aspiration imaging equipment in rural and monitoring of parasitic diseases such of contents, injection of a scolicide district hospitals. as amoebiasis, schistosomiasis and solution (hypertonic saline or Chagas disease. For example, alcohol) and re-aspiration of the Clinical uses hydatidosis is quite common in contents again. At present this Mediterranean, West African and technique is used in Croatia, France, Ultrasound is useful for diagnosing a South American countries. The Italy, Paraguay, Tunisia, Turkey and wide range of diseases and patholog­ asymptomatic infestation rate varies Yugoslavia. ical changes in the thyroid, liver, from 1.8 % in Tunisia to 5.6% in Ultrasound was first used for gall bladder, pancreas, kidney, blood Turkana, Kenya. Studies have medical investigations and treatment World Health • 48th Yeor, No. 3, May- June 1995 17

diagnostic purposes have been and training process in this technol­ reported in more than three decades. ogy. Since its creation in 1986, ~countries MASU has organized training courses in Algeria, Burundi, Chad, Availability and cost Egypt, Kenya, Morocco, Syria, Despite considerable and growing Tunisia and Turkey. worldwide investment in diagnostic The price of an ultrasound imaging technology, about two­ machine can vary from US$ 10 000 thirds of the population in develop­ for a simple general purpose scanner ing countries do not have access to to US$ 300 000 for specialized even the most basic X-ray or ultra­ equipment. Fortunately, a simple sound diagnostic services. In 1988 unit is suitable for 70-80% of the there were only about 1000 ultra­ ultrasound examinations for diagno­ sound units for the 600 million sis of the most common clinical people in Africa. Today, according problems. A WHO group of experts to rough estimates, there are about has drawn up technical specifica­ 10 000- a tenfold increase in five or tions for this kind of machine, which six years. However, in many devel­ is portable and well adapted to oping countries ultrasound is used conditions in developing countries. by a wide spectrum of medical It appears that such units are at professionals including doctors, present produced by several com­ nurses, midwives and others who mercial companies. have not had proper training in this In conclusion, it would not be an imaging technique. This frequently exaggeration to say that ultrasound leads to the misuse of ultrasound has revolutionized medical practice which, in addition to the potential in terms of providing easier access harm done to the patient because of and increased quality of diagnostic incorrect diagnosis, increases the service for patients. However, much cost of health care. At present, work is still needed to make this therefore, the education and training useful technology accessible to all of medical staff who want to use who could benefit from it. • ultrasound is a key issue in many countries. The nongovemmental professional associations such as the Or Hassen A Gharbi is Professor of Radiology Mediterranean and African Society and former President of th e Mediterranean and of Ultrasound (MASU) and the African Society of Ultrasound (MASU). His address is I 2 rue Mohamed Slaheddine about 25years ago. Today it has a World Federation for Ultrasound in Mutuelleville, Tunis I 082, Tunisia. Or M. W. Medicine and Biology (WFUMB) Wachira is with the Department of Diagnostic wide variety of uses. For instance it RadJOiogy, University of Nairobi, Kenyatta is used to guide various procedures are collaborating with WHO in National Hospital, P 0. Box 19676, Nairobi, such as drainage of abscesses, attempting to improve the standards Kenya. cryogenic surgery on the liver and prostatic cancer, implantation of radioactive seeds for cancer therapy, and fine-needle biopsies from such organs as the liver, pancreas, kidney or lymph nodes. Since the beginning of the use of ultrasound in medicine, the question of its safety has been a matter of concern among scientists and public health professionals, and has stimu­ lated intensive discussions in the scientific literature. According to the current data, although some evidence suggests the possibility of a risk occasioned by ultrasound exam­ ination of the fetus, no human injuries resulting from its use for 18 World Health • 48th Year, No. 3, May-June 1995 Nuclear medicine Yasuhito Sasaki & Kiyoko Kusakabe

Data from the scintillation camera can be interpreted by computer to permit a refined diagnosis.

uclear medicine is the applica­ the localized physiological and tion of tracer technology to metabolic function in a tissue, organ medicine. Chemical com­ or lesion which can be displayed as a pounds labelled with a radioisotope, functional image. The radioisotopes which are called radiopharmaceuti­ used have a half-life as short as six cals, are either administered to hours, with very little radiation patients (in vivo studies) or labelled exposure for patients. compounds are mixed with other Nuclear medicine is constantly reagents in test-tubes to measure minute quantities of hormones, How it began expanding through the certain drugs, and other substances. introduction of new radio­ The amount of radiopharmaceuticals Shortly after Rontgen's discovery of and labelled reagents is so small that X-rays, the experiments of Henri pharmaceuticals and new it does not interfere with the natural Becquerel led to the discovery of instruments. Special behaviour of the target substance in what was later named "radioactiv­ the body or with biochemical or ity" by Marie Curie. Further studies radiotracers, for instance, are immunological reactions in test by Marie and Pierre Curie, Ernest tubes. Rutherford and Frederick Soddy making it possible to study After an intravenous injection of opened the door to the medical fatty acid metabolism in the such a compound, the patient just lies applications of radioisotopes on the bed while a scintill ati on detec­ emitting ~- and y-rays. heart muscle. tor called a gamma camera measures George von Hevesy was the first the radioactivity to record multiple to use radioisotopes to trace the images of the organ concerned from behaviour of a substance in plants different angles. These images are and animals by monitoring the then interpreted by a computer and radioactivity. This tracer principle the tomographic images serve to was first applied to human beings by detect the location of any abnormal­ Hermann Blumgart and Soma Weiss ity. Such in vivo procedures can in the late 1920s to measure the detect a diseased organ by measuring speed of the bloodstream. They World Health • 48th Yeor, No. 3, Moy-June 1995 19 injected a radioisotope into a vein of available for the past few years, collaborative efforts in physics, the arm and measured the time it making it possible to study fatty acid chemistry, computer science, took for radioactivity to reach the metabolism in the heart muscle. physiology, clinical medicine other arm. Labelled monoclonal antibodies have and, recently, immunology. Its The discovery of artificial radio­ been attracting great interest and are applications, in some instances, may isotopes in 1934 by Irene Curie and the subject of vigorous research for need support by a national health her husband Frederic Joliot gave a use in both diagnosis and therapy. care system because of the high cost. boost to the application of the tracer An imaging instrument called The development of relatively inex­ principle. The medical application of positron emission tomography pensive devices and radiopharma­ substances labelled with radioiso­ (PET), in combination with a small ceuticals is therefore important if topes was accelerated after radioiso­ in-house cyclotron, can produce nuclear medicine services are to be topes were made available to the radioisotopes which decay very available to all who need them, private sector in 1946 in the USA. rapidly with half-lives as short as two including patients in the developing Measurement of insulin levels in hours. This has excited clinical countries. • human blood was first reported in research workers in nuclear medicine 1959 by Solomon Berson and since with PET we can evaluate re­ Rosalyn Yalow. This new technique gional tissue metabolism, which re­ was named radioimmunoassay (RIA) veals tissue consumption of oxygen, and opened up a new horizon for the diagnosis of hormonal disorders.

Frequent diagnostic tests

In Japan, about 6600 in vivo studies are performed every day in some 900 nuclear medicine facilities in hospi­ tals. The most frequently performed diagnostic tests are bone scintigraphy using labelled phosphate compounds - the most sensitive test for detecting bone metastasis -followed by tumour scintigraphy, myocardial scintigraphy and brain perfusion scintigraphy. Radiopharmaceuticals are also used for therapy. In 1992, for exam­ ple, 2000 Japanese patients with hyperthyroidism and 1000 thyroid Nuclear images of the brain. Positron emission tomography and magnetic resonance ore helping cancer patients with metastasis were doctors to understand some of the mysteries of the brain 's functions. treated. Therapeutic use of unsealed radioisotopes has been playing an glucose, amino acid and fatty acid. Professor Yosuhito Sosoki is Chairman of the increasingly important role since the Moreover PET can visualize acti­ Deportment of Radiology, Facu lty of Medicine, introduction of monoclonal antibod­ vated nerve cells, which will make it the University of Tokyo, 7-3-1, Hongo, Bubkyo-Ku, Tokyo I 13, Japan, and Professor ies labelled with beta-ray-emitting possible to study higher brain func­ Kiyoko Kusokabe is with the Deportment of radioisotopes, which bind to tumour­ tion such as speech, cognition, think­ Radiology, Tokyo Women's Medical College, related antigens produced by the ing and emotion. The use of nuclear 8-1 Kowodo-machi, Shiniuku-ku, Tokyo 162, Japan. Or Sasaki is also Director of the WHO cancer and irradiate the cancer tis­ medicine to help us to understand Collaborating Centre for Diagnostic lmaging at sues locally. Similar substances have human behaviour will thus play an the University of Tokyo. been used for the effective control of important role in evaluating intractable bone pain caused by bone psychiatric patients, including those metastasis. with dementia. Nuclear medicine is constantly It will also be possible to measure expanding through the introduction the sensitivity to drug action of of new radiopharrnaceuticals and individual patients by visualizing the new instruments. In cardiac nuclear sites of drug action. The therapeutic medicine, for example, new myocar­ drug regimen can then be precisely dial perfusion agents labelled with tailored to suit the individual's need. special radioisotopes have been Nuclear medicine is the result of 20 World Health • 48th Year, No. 3, Moy Jun e19 95 Radiotherapy: still young after almost a hundred years Jean·Ciaude Horiot &Suzanne Naudy

improve our understanding of how radiation works and makes a major contribution to the effec­ tiveness with which it is used on both normal and diseased tissues.

Modem radiotherapy has three main concerns: efficacy, quality of life, and safety. With regard to efficacy and quality of life, which are often hard to separate, radiotherapy selec­ tively destroys the cells responsible for setbacks after surgery in more than 90% of the cases in which it is used. In treatment for breast cancer, for ~xample , this treatment is often so effective that it is impossible to see that the breast has been treated. There are two methods of particu­ lar note which make it possible to select the area for irradiation with A patient suffering from cancer of the lymphoid tissue, Hodgkin's dis ease, receives treatment wh ich combines radiotherapy and anti-cancer drugs. greater precision than before. (1) Brachytherapy with iridium 192, which is the most commonly used radionuclide today. A piece of iridium wire, a few tenths of a milli­ -rays were first used to treat a Past achievements and future metre in diameter, can be inserted, cancer patient in December expectations are based on three usually under local anaesthetic, in X1895, only four weeks after disciplines. various parts of the body such as the their discovery by Rontgen. A few • Clinical medicine and a century's cervix and uterus, breast, ear, nose, months later, in March 1896, Henri experience in the use of (a) exter­ throat, oesophagus and bronchi. It Becquerel discovered radioactivity. nal radiotherapy, nowadays delivers a very high and very local­ Less than two years after that, Marie increasingly by means of photon ized dose which leaves adjacent and Pierre Curie announced the and electron linear accelerators; tissues unaffected. existence of two radioactive sub­ and (b) brachytherapy (curiether­ (2) Conformation radiotherapy, stances: polonium and radium. The apy), which is internal radiother­ which is guided by three-dimen­ beneficial consequences of these apy by means of radioactive sional dosimetric modelling using three amazing years of discovery are sources placed in tissues or nat­ the modem imaging techniques of still unfolding now, a century later. ural cavities for periods ranging computed tomography and magnetic Radiotherapy, alone or in association from a few minutes to a few days. resonance imaging. Prior to treat­ with other methods such as surgery • Radiophysics, which makes it ment, a computer-generated virtual and chemotherapy, has become one possible to measure the exact patient is used to determine the of the main weapons in cancer treat­ amount of radiation delivered to configuration closest to the ideal ment, and often the one which most the patient (the dose) and to prescription for the maximum dose effectively cures while causing distribute it effectively so as to to the tumour and the minimum dose minimal disturbance to the anatomi­ destroy cancerous tissue whilst to the healthy structures and organs cal structures and functions con­ preserving healthy tissue. at risk. This method has raised great cerned. • Radiobiology, which continues to hopes, as it should make it possible World Health • 48th Year, No . 3, May- June 1995 21

A new image of man: o computer-generated "patient" makes it possible A patient suffering from lung cancer receives radiotherapy using o linear to determ ine the ideal radiation dose for treating o tumour. accelerato r. to increase the dose according to treatment plan and even the possibil­ being. • need. For many cancers, an increase ity of using the same treatment in a of 15 % in the dose leads to an in­ subsequent session or a different crease of similar proportions in the hospital. Today it is a fundamental rate of cure. Thus, for certain local­ part of both international clinical ized cancers, a success rate of over research and the safety of radiother­ 90% has already been reached or can apy in daily practice. be expected in the coming years. Unfortunately, radiotherapy is Professor )eon-Cioude Horiot is Cha irman of Finally, safety: the practice of not accessible to everyone on the the International Society of Radiation quality assurance, common enough planet. The industrialized countries Oncology (ISRO), Professor of Radiation in industry but still all too rare in have 90% of the equipment and the Oncology at th e University of Oiion in France, and Head of the Radiotherapy Service at the medicine, has developed rapidly in skilled personnel needed to use it. "Georges-Franr;:ois Lee/ere" Cancer Control radiotherapy since 1980 because This situation should be viewed not Centre, 1rue du Professeur Morion, BP 1544, 2 1034 Diion Cedex, France. everything can be measured and as a discouragement, but as a stimu­ Or Suzonne Noudy is Head of the recorded. Quality assurance tech­ lus to further progress: investment Rodiophysics Unit at the some Centre. niques are now used to check the in this field is almost bound to be amount of the dose, the reliability of extremely beneficial, in terms both the installations, the validity of the of economics and of human well-

An orthographic puzzle This year marks th e cente nary of Rontgen 's great discovery. Ironically, th e d iscovery launched one of th e more controvers ia l four-l etter words in the Eng li sh language. The word "X-ray" is used as a noun with two distinct meanings (the ra d iation itself and also the processed ima ge), as a n adjective (as in X-ray equipmen t) and as a transitive verb (to X-ray an object or a patien t). Bu t should it be writte n with a capital X or not, and shoul d it have a hyphen or not? Guidance and precedent may in fl uence th e use of Eng lish , but never immutable rules ! Originally, th e word may have started as a "proper na me " w ritten w ith a capital "X" . But today it is only one of many forms of electromagnetic rad iation , which includes light, heat a nd ultra-violet radiation. So some experts use "x-ray" while others stick to "X-ray". Rontg en's original paper of 1895 refers to "X-Strahlen ", since in German a ll nouns start w ith a capital . But should that influence modern Eng li sh w riting? The Shorter Oxford Dictionary even includes the possi bility of replacing the hyphen with a space (x ray). The im pli cation that "X" (or "x") can have a meaning by itself, is hardly a tenable proposition. "X" is not a word but simply a prefix th at g ives a special mea nin g to "ray" (compare a lpha-ray, gamma-ray, etc). As a connector of the qua lifying prefix to its body, the hyphen seems to be ma ndatory. Then the question arises w hether to use a capital "r" - X-Ray. In the end, th e only consensus view is that the spelli ng should be consistent throughout any given publication ! Contributed by Colin W. Robertson, formerly in charge of the radiological section of the Medical Devices Directorate of the U.K. Deportment of Health, and a member of expert committees of the International Electrotechnicol Commission {l EC). His address is 7 A Tolbots Drive, Maidenhead, Berks S16 4LZ, England. 22 World Health • 48th Yeor, No. 3, Moy June 1995 Quality assurance in radiotherapy Hans Svensson &Bjorn Zackrisson

ccording to WHO's estimates, X-ray pictures delineated the conventional method missed part of about 9 million new cancer tumour's position and volume in the the tumour in up to 40% of the cases cases occur each year world­ patient. A simple cross-section on a examined. Much research is being wide. This number is expected to scale of 1: 1, based on the contour of devoted to improving the accuracy increase to about 15 million by the the patient, was constructed to show with which the tumour's position in year 2015, with about two-thirds of the suspected volume of the tumour the body can be determined. these in the developing countries. A for radiotherapy and also to indicate recent European Union document the healthy tissues that should have a states that radiotherapy is no longer low dose. The uncertainty in the Dose planning the key research topic but is the most delineation of the tumour was often widely used treatment for cancer. In large, and the radiotherapist had to For curative radiotherapy an accurate the developed countries it is involved increase the radiation field in order dose plan is required. In many ad­ in almost half of the administered not to miss parts of the tumour. The vanced radiotherapy centres, dose cancer treatment, either on its own or prescribed dose had to be reduced planning was still being done without in combination with surgery and/or when large volumes were irradiated, a computer at the beginning of the chemotherapy. In the future, radio­ and this decreased the chance of 1980s. Today even small depart­ therapy will undoubtedly play an eradicating the tumour. In spite of ments can often afford a treatment increasingly important role in most these problems many patients were planning system, as it can be run on countries. cured. an ordinary personal computer. The introduction of computerized Computer-based dose planning tomography (CT) has improved the generally increases the accuracy of dose determination, but it can also Exact diagnosis and tumour possibility of delineating some tu­ mours accurately. When this method cause errors, especially in the hands size was first introduced the tumour's of untrained persons. Input data, determined by the medical physicist, The decision to use radiotherapy position was often determined by must be available from the local must be based on careful determina­ using both conventional X-ray equip­ radiotherapy machines. The incor­ tion of the histological type and ment and CT-scanners. In several rect use of dose planning systems has extent of the tumour. Traditionally, centres it was discovered that the been known to lead to large errors; for example in one centre doses that were 20-30% too low were given to several hundred patients. The dose planning system should therefore be handled by a competent medical physicist and a quality assurance programme is essential.

Dose measurement

Modern radiotherapy is based on the experience of a large number of radiotherapy departments all over the world. The amount of radiation that is required to control a certain type of cancer without causing serious com­ plications is a matter of continuous discussion in scientific journals. The Reviewing computed tomography images: CT-scanners delineate tumours very accurately. difference between a dose level World Health • 48th Year, No. 3, May- June 1995 23 which achieves local control of the 1000 new cancer cases occurring in a cancer and one which causes serious Irradiation of the patient given year, about half of which are or fatal complications is sometimes treated with radiation. It would very small. The radiation oncologist The radiation field arrangement therefore require at least 10 000 must therefore make sure that his planned for the patient is checked radiation machines for external department can measure the dose so with a special X-ray diagnostic unit radiotherapy plus a large number of that it complies with the international which serves as a simulator. The radiation sources for brachytherapy standard, and determine the dose to beam directions and field sizes are in developing countries by the year the tumour and organs at risk with a set up as for treatment with the ther­ 20 15 if the need is to be met. There high degree of accuracy (generally to apy machine. If there is a risk of the is concern about the spread of radio­ within 5% of what is prescribed). patient moving during treatment for active material to a large number Several international organiza­ which the precision of the field of hospitals. For instance, what tions are involved in the standardiza­ settings is critical, fixation should be happens when these sources are no tion of dose measurements. The used for both the simulation and the longer in use? International agencies International Bureau of Weights and therapy irradiation. such as WHO and IAEA can greatly Measurements in Paris has estab­ The first treatment of the patient help in organizing activities such as lished an international reference at the therapy machine is crucial as setting up SSDLs, but the direct standard, and IAEA and WHO have the same parameters are used in responsibility must be shouldered by jointly promoted the establishment of subsequent treatments, of which the countries themselves. Adequate a system known as the secondary there are usually 30 or 40. The staff, with qualified radiation oncol­ standards dosimetry laboratory whole team responsible for this ogists and medical physicists, as well (SSDL) network, which now covers procedure- i. e. the radiation oncol­ as equipment for dose measurements most of the world. IAEA is respon­ ogist, the medical physicist and the and a programme for quality assur­ sible for checking the quality of the radiographer- should participate in ance are needed. Certainly, with calibration services used by the it (see Figure, below left). Dosi­ adequate infrastructure and skill, individual laboratories in the net­ meters for in vivo measurements are radiotherapy will cure or give pallia­ work. To check individual centres, recommended for checking the tive relief to a large percentage of the IAEA and WHO have organized correct dose to the patient (see world's cancer patients without services for hospitals; 1000 radio­ Figure, below right). undue ri sk. • therapy centres have now been checked and about half of them are able to calibrate the treatment beams Professor Hons Svensson is with the Radiation Future Physics Deportment, Umea Univers ity, 5-90 l to within 5%. 85 Umea, Sweden, and is also the In advanced countries today there is Secretory-General of the International Organization for Medical Physics (IOMP) . one high-energy therapy unit (accel­ Or Biorn Zockrisson is with the Deportment of erator or Cobalt-60) for every 500 to Oncology, Umea University.

A radiographer, a radiation oncologist and a medical physicist plan the Dosimeters applied to the skin allow radiation oncologists to monitor the dose of radiation to be given to o patient. optimal irradiation dose. 24 World Health • 48th Yeor, No. 3, Moy-June 1995 Protection against radiation in medicine Cesar F. Arias &Jorge J. Skvarca

The protection of patients is the area in which the greatest reductions in human exposure to radiation can be made - by improving the quality of equipment and practices and raising the standard of justification for procedures.

Radiology in paediatrics ca lls far special protection procedures for the young patients. the probability of cancer grows with the dose of radiation absorbed. he discovery of X-rays by Whenever radiation is used for Rontgen in 1895 and radioactiv­ The risk of radiation any purpose, people working with it, Tity by Becquerel in 1896 opened as well as some members of the up the field for using ionizing radia­ Human beings are naturally exposed public, are unavoidably exposed to tion in science and technology. This to the radioactive substances of the small doses of radiation under proved to be a valuable tool for earth, and to cosmic radiation. normal circumstances. In the case research on the structure of matter, Globally, the average dose per of medical use, the patient is delib­ and its applications in medicine have person is about 2 millisieverts (mSv) erately exposed to radiation in order been explored since the beginning of per year, which is about 10 times the to obtain the necessary diagnostic the century. Ionizing radiation is dose received from a simpleX-ray information or for treatment. In now used for medical purposes in examination. addition, accidents can occur in three areas: diagnostic radiology, When X-rays and radioactivity which people receive high doses. radiotherapy, and nuclear medicine. first came into use, little was known Throughout the world, there are about the effects of ionizing radiation about 800 000 X-ray units being used on health. It was the acute effects, Protection against radiation for diagnostic radiology; 4000 cobalt such as skin erythema, cataracts and radioactive sources and 1800 accel­ reduced production of blood cells The Second International Congress erators being used for radiotherapy; that were recognized first. These of Radiology, held in Paris in 1928, and 13 000 nuclear medicine clinics only occur when tissues receive recommended the establishment of using unsealed radioactive sources doses of radiation several thousand an international organization to study for diagnosis and therapy. times as large as those received by an the question of protection against The growing complexity of average person in a year from natural radiation. This was the origin of the radiation medicine can be seen in the radiation. The carcinogenic effects International Commission on use of such devices as computerized were discovered later, and some Radiological Protection (ICRP) . The tomography in diagnostic radiology, information on them was gathered ICRP has produced about 70 publica­ linear accelerators in radiotherapy, from studies on patients who had tions and its recommendations have and positron emission tomography in been treated with radiation and been followed by most countries, as nuclear medicine. This has led to the workers painting radium on the dials well as by various international need for maintenance and quality of watches. After the bombing of organizations such as WHO and the control of equipment, using highly Hiroshima and Nagasaki, large-scale International Atomic Energy Agency specialized personnel. epidemiological studies showed that (IAEA). World Health • 48th Year, No. 3, Moy-J une 1995 25

able, are set as follows: occupa­ ment and procedures. tional exposure should not exceed The protection of patients is now 20 mSv per year and no member receiving particular attention, as it is of the public should receive more the area in which the greatest reduc­ than 1 mSv per year. The risk of tions in human exposure to radiation accidents must be considered. can be made. The global collective • All exposure should be kept as dose received by patients from diag­ low as reasonably achievable. nostic radiology is 5000 times Protection against radiation is a greater than the dose received by the matter of professional culture, world's population from nuclear and national regulatory authori­ power production. A significant part ties work to promote appropriate of that dose could be avoided without attitudes as well as compliance loss of health benefits by improving A radiation protection specialist checks with the rules. To provide them the quality of equipment and prac­ equipment to ensure that it meets safety with the necessary information tices and raising the standard of requirements. for doing this, the International justification for procedures. To In 1990 the Commission pub­ Basic Safety Standards for prevent accidents where radiation is lished ICRP Publication 60, which Protection Against Ionizing used for medical purposes, safety provided an update on radiobiology Radiation and for the Safety of measures have to be adopted in the and the current conceptual frame­ Radiation Sources were prepared design, installation, use, repair and work for radiation protection. The jointly by FAO, IAEA, ILO, the eventual disposal of equipment. • following points from this publica­ Nuclear Energy Agency (NEA) tion give an indication of its basic of OECD, the Pan American philosophy. Health Organization (PAHO) and Mr Cesar F. Arias is Chairman of the Advisory • Every exposure to radiation may WHO. WHO also works with Council on Radiological Applications and a former member of the ICRP Committee 3 on have detrimental effects on countries to improve standards Protection in Medicine. His address is Pampa human health, since the carcino­ through training and consultation 2669- 5A, {CP 1428}, Buenos Aires, genic effect of radiation cannot be on the procurement and use of Argentina. Mr )orge). Skvarca is Chief of the Department of Medical Devices at the completely avoided. equipment. Argentinian Ministry of Health. His address is • No practice involving exposures P.O. Box 3268, Correo Central 1000, Buenos Aires. to radiation should be adopted Medical establishments are the most unless it produces sufficient numerous and widespread source of benefit to the exposed individuals radiation in any country, and because or to society to offset the radia­ their activities are mainly beneficial, tion detriment it causes. the risks involved are often ignored. Radiation expert This makes the promotion of proper • Dose limits, defined as a level of In the same year that radioactivi ty dose above which the conse­ protection a difficult task. In the case was discovered - 1 896- one of quences for the individual would of a patient's exposure, the risks and the leading sc ientists in med ica l be widely regarded as unaccept- the benefits apply to the same person, radiation physics and radiation and must be carefully weighed protection, Rolf Maximilian Sievert, against each was born in Sweden He entered other by the the med ical physics field in 1920 physician respon­ and is known for his theoretica l sible. Dosage calculations of the dose distribution must be limited around radium tubes (Sievert integral), for the design of to what is strictly dosemeters (Sievert chambers), and necessary; limits for his research in radiation have not been set protecti on. because they Sievert was for many yea rs depend on the chairman of the International possible benefits, Commiss ion on Radiological but reference Protection (IC RP), and the in itiator levels are being and chai rm an of th e United Nations suggested for use Scientific Committee on the Effects in radiology and of Atomic Radi ation (UNSCEAR) nuclear medicine He retired in 1965 and was honoured after his death by having as a means of the unit for "dose equivalent" na med judging the after him as the Sievert (Sv) A radiographer views the patient from inside her protected control booth. quality of equip- 26 World Health • 48th Yeor, No. 3, Moy-J une 1995 Radiology in the next hundred years Alexander R. Margulis

f we review the for brain tu­ accomplish­ mours, while I ments of interventional imaging during radiology is the last 100 years making advances since Rontgen's with the intro­ discovery of duction of X-rays, we must catheters through conclude that the femoral progress was artery to carry initially slow but radiotherapy to gained speed, an affected with momentous organ. Indeed advances in interventional technology. The radiology, which relatively early in the beginning breakthroughs used only fluo­ were the image roscopy with Coronary angiography examination. A radiation-opaque dye injected into the body outlines intensifier and arteries and shows up any obstruction on the screen. television view- television view­ ing for imaging ing, which made interventional control, is today also employing radiology possible and transformed ultrasound, CT and now magnetic gastrointestinal fluoroscopy into an To be able to prosper in the resonance imaging. objective, detailed, data-gathering future, medical imaging must discipline. Radiology benefited from continue to decrease in the spin-off of space exploration and . . . . Threat to progress Cold War defence technology, result­ mvasJVeness, mcrease m ing in breakthroughs in computers, The explosive progress in imaging, electronics, the move from tubes to sensitivity and specificity and however, has also coincided with the transistors to printed circuits on general rise in the cost of medicine, boards to silicone chips, miniaturiza­ - more than anything else - producing a reaction which is threat­ tion, telecommunications and fine­ remain affordable and ening further progress. With large detail television screens. expenditures for health everywhere As a result of these technological patient-friendly. and the glaring visibility of expen­ advances, new imaging disciplines sive imaging instruments, the general appeared in the 1970s. Ultrasound feeling is that high-technology imag­ made it possible to study the blood speed of scanning and more detailed ing should be stopped and that the flow, while fetal ultrasound is imaging. spread of expensive cross-sectional discovering congenital disorders Magnetic resonance imaging has imaging equipment should be heav­ in utero and makes early therapy brought about fast, highly informa­ ily controlled. Government support possible. Intra-operative ultrasonog­ tive imaging and has become a for imaging research is slowing and, raphy is capable of finding disease competitor to CT in everyday cross­ as industry finds this less profitable, within organs such as the liver and sectional high-detail imaging and it cannot support bold, new, adven­ guiding the surgeon during an opera­ problem-solving. Magnetic reso­ turous approaches. It is, therefore, tion. Computerized tomography nance spectroscopy is becoming a highly unlikely that new cross­ (CT) has moved towards greater clinical problem-solving modality sectional imaging techniques will be World Health • 48th Year, No . 3, Moy-June 1995 27 developed in the near future. particularly in the abdomen. Biomagnetism may be an excep­ As imaging must closely follow tion and is most likely to become a the mainstream of medicine, all of clinical new imaging modality. It is these modalities will have to be important in brain surgery to avoid integrated and further developed to damaging critical motor and sensory serve genetic medicine. With human centres, and its application in the genome identification of disease heart is in detecting arrhythmias, a gene carriers and gene suppressors, frequent cause of unexpected sudden new screening tests will have to be death. Infrared laser CT shows some developed. The situation is not prospects of feasibility but needs simple, as there are diseases that will government or industrial funding, happen almost inevitably because of which is at present in short supply. genetic predisposition, but most With this bleak and pessimistic disease-related genes only increase outlook, what is the future? susceptibility, and the actual trigger­ Existing cross-sectional equip­ ing of disease may involve many ment will become less expensive, factors. A biomagnetism imaging system. Its two sensors and there will be a spectrum from pick up magnetic signals produced by electrical Substitution gene therapy is still low and very affordable to intermedi­ activity in the brain or in other organs . in its infancy and is not without risk, ate and then to highly sophisticated while general amniotic genome equipment. The integration of vari­ an instant and could be transferred testing of the fetus still lies in the ous imaging modalities through anywhere. Teleradiology will make future. computer programs will become an it possible to obtain second readings To be able to prosper in the fu ­ everyday clinical reality, with better and consultations almost instantly. ture, medical imaging must continue display, increased sensitivity and Radiology will eventually be­ to decrease in invasiveness, increase improved specificity. However, with come filmless as everything is read in sensitivity and specificity and­ the mushrooming of information, from the computer screen. This will more than anything else- remain there is the danger of being over­ make radiology more time- and cost­ affordable and patient-friendly. • whelmed by it, and it will be neces­ effective. There is probably going to sary to develop picture-archiving be a separation, at least in practice, communication systems, a needed between diagnostic and interven­ tool that will link physicians and tional radiology. The latter will departments in the same institution become increasingly more fused with and will also communicate with surgery. Ultrasonography will be­ other centres throughout the world come more and more the stethoscope Or Alexander R. Margulis is Special Consultant that use computers. All radiography of the future, CT will continue to to the Vice-Chancellor, University Advancement will have to become digital in order increase in speed, and magnetic and Planning, University of California, resonance imaging will continue to San Francisco, 3333 California Street, to be properly archived and retrieved. Laurel Heights, San Francisco, Images will be randomly retrieved in be a problem-solving modality, CA 94 143-{)292, USA

A magnetic resonance imager, specially designed for surgical Angiogram of the aorta and superior mesenteric artery after repair of an interventions . aortic aneurysm. 28 World Health • 48th Year, No. 3, Moy-June 1995 The ethics of new technology Sneh Bhargava

Human embryo. The passibility of examining the unborn baby raises acute ethical questions far health professionals.

dvances in radiology and Even some obstetricians and radiolo­ imaging science have brought gists consider that sex selection and Ainto being a new medical selective abortion of the unwanted speciality concerned with the unborn sex can be morally justified, arguing fetus. This has raised important in favour of "population control" or ethical questions for health profes­ the heavy social responsibility of In this "space-age" of sionals such as: do you abort a fetus bringing up female children in sophisticated gadgetry, with Down's syndrome, hydro­ certain developing countries where cephalus, meningocele, congenital girls- especially impoverished patients prefer to have their heart disease, or bilateral renal disor­ girls- face a lifetime of discrimina­ ders? Or do you institute pre-natal tion and even worse. illness attended to by the intervention? Or do you permit these A quite different problem arises new technologies, which have defective fetuses to be born? as a result of the progress and evolu­ Further ethical issues arise. Who tion of high technology in health care areassuring ring to them. makes these decisions: doctors, and its escalating costs. This con­ But who gets these services - parents or both? Does the newborn cerns the ethical and moral issues of child or the unborn fetus have the availability, accessibility and afford­ the needy or the rich? fundamental right to be born with a ability of the services that radiology sound mind and body? Technological can offer. Are they a right or are they advances have also provided a means a privilege? Whose responsibility is of sex selection and, in some it to ensure that the needs of the cultures, parents may be inclined many are not ignored while the to destroy unwanted female fetuses. privileged few are favoured? World Health • 48th Year, No . 3, Moy-June 1995 29

Such questions form part of the 500 000 and the broader problems that health care operating costs professionals and the community in can only be re­ general have to resolve, namely to couped by using balance- on the one hand - self-care, the machines and equity, social justice, human well­ the services they being and obligations to the vulnera­ provide to the ble against- on the other hand - maximum. Less rising costs, cost-benefit, resource expensive ser­ allocation and the inclusion or exclu­ vices may be and sion of specific population groups. are being by­ Have physicians, economists, passed in order to epidemiologists, social scientists, increase the use of policy-makers and the community these costly thera­ The doctor reassures o patient who is about to undergo a scanner put these on today's or tomorrow's pies and diagnos­ examination. Is access to sophisticated and costly technology like this a agenda? tic aids. There is right or a privilege? definitely a psy- chological aspect associated with in US males are attributable to From X-rays to scans complex technology. Patients would tobacco smoking alone, and 90% rather have their illness attended to of oral cancers in developing There is no doubt that the radiologi­ by the newer technologies, which countries are due to tobacco chew­ cal and imaging sciences have made have a reassuring ring to them in this ing. One-third of all cancers are unprecedented progress from simple "space age" of sophisticated gadget­ related to tobacco use, which is X-ray films to the era of anatomical ry. But the ethical question for the theoretically under our control but scans, whether they be computerized medical bureaucracy is: who gets very heavily industry-pushed. tomographic scans, ultrasound scans, these services, the needy or the rich? The message should be clear to scintiscans, or magnetic resonance The producers of medical equip­ all. The most insidious agent for scans, whether made with ionizing or ment have done a superlative job in disease today is ourselves, the only non-ionizing sources. Such scans persuading health care providers of truly effective treatment is awareness have not only laid bare the human the merits of their engineered and and prevention, and the only valid anatomy with millimetre precision expensive merchandise. They also prevention is to make positive but have now embarked on unravel­ provide the wherewithal of financing changes in lifestyles. This is an ling the brain physiology and body strategies that make the debt burden ethical responsibility for the entire biochemistry at the molecular level, easy, even if this results in overuse to community. To make one's own non-invasively. They have brought recoup operational costs. Inevitably health someone else's duty is unfair such precision and confidence to this high-tech equipment is installed to the society of which we all form a medical diagnosis as never before only in the capitals and big cities, to part. Doctors must practise not only and are actively involved in every the detriment of rural areas already the science of health care but also field of medicine from the unborn lacking access to health care ser­ the art of compassion, taking into fetus to the brain dead. So much for vices. Yet how else can the costs be account availability, accessibility the positive side. recovered? and affordability. The medical care On the negative side, they have In this connection, the story of system with all its sophisticated changed medicine from being an art cancer is a classic example of the gadgetry has, in the end, less impact with a human face to that of a com­ need for partnership in ethics be­ on health than individual behaviour, plex science with a dollar value. tween health professionals, the lifestyle and environmental factors. Their rising costs have increased the community and industry. In the mid- gap between the haves and the have­ 1960s there was a great deal of opti­ • nots in terms of the availability of mism about curative cancer research; quality health care. The most vulner­ by the mid-1970s that research did able, the poor and those who are not fulfil the expectations of the most in need of health care are get­ profession and the community. The ting less and less. The new technolo­ cancer control movement shifted Or Sneh Bhargava is a former Director and Professor of Radiology at the A/I India Institute of gies have usurped limited resources, away from imminent cure towards Medical Sciences, New Delhi, India, and away from preventive health care prevention strategies and efforts to Former Chairman of WHO's South-East Asia Advisory Committee on Health Research. Her and primary health care - in part protect people from harmful environ­ address is A-I 03, New Friends Colony, New because of the powerful lobbies that ments. Increasingly now scientists Delhi I I 0065, India. industry has created among the consider cancer to be 70-90% envi­ medical administrators. ronmentally and lifestyle induced. A single scanner may cost US$ For example, about 80% of cancers 30 World Health • 48th Year, No. 3, Moy- June 1995 Multidisciplinary research for health Boutros G. Mansourian &Bruce MeA. Sayers

he discovery of X-rays is a fine represent the combination of two Doppler investigation of regional example of the contribution technologies: microelectronics and blood flow, depend on quite sophisti­ Tmade by the physical sciences, enzyme catalysis. Other detection cated processing which is transparent together with the biological sciences, techniques depend on antibody­ to the user. Consequently it will be to the progress of medicine in the last binding reactions rather than enzyme increasingly feasible to perform 100 years. More recent advances in catalysis, and these offer the possi­ dynamic measurements, in "spatia­ diagnostic technologies are the result bility of assaying an increasing temporal terms", i.e. , displaying of important multidisciplinary range of drugs and hormones. "surface maps" of the physiological research in medicine and the natural Current and future developments variable as a series of "snapshots" in sciences. For example, the biotech­ in biosensor technology will be "real time", at a hundred times or nology industry has grown as a result important for monitoring water and more per second. of the use of the hybridoma tech­ air pollution, for monitoring bio­ Imaging technologies such as nique for producing monoclonal anti­ processing in the food industry, for ultrasonography, computerized bodies; recombinant DNA methods quality evaluation of food products tomography, magnetic resonance are thus available for prenatal screen­ kept in storage, and for veterinary imaging, and positron emission ing and, where necessary, for post­ purposes. Applications in primary tomography have grown out of basic natal examination for inborn errors health care would also become research in physics, mathematics and of metabolism. Also, the fact that evident, because such devices are electrical engineering. In addition to particular types of tumour generate inexpensive and easy to use. expected improvements in speed and specific proteins offers opportunities Electronic diagnostic equipment resolution (e.g., by 1000 times in the for the development of specific assay is developing.rapidly because still experimental "ion computer techniques for the early detection of microchip technology has made it tomography"), new efforts are being cancer. possible for the individual instru­ directed towards extracting informa­ ment to be attached to a personal tion about function for a better evalu­ computer or for a microcomputer to ation of planned treatments. Of Improving diagnosis and be included within it. Advances in particular interest is the use of ultra­ evaluation diagnostic procedures, such as sound imaging, achieved by echo­ electro- and magneto-cardiography, reflection and Doppler effect, which Developments in the physical electro- and magneto-encephalogra­ allows conventional visualization as sciences and technology have pro­ phy, ophthalmography and the well as measurements of flow and duced three major kinds of diagnos­ tic procedures: the wide range of simple, commercially produced disposable kits for the testing of body fluids in the field; electronic diagnos­ NUMERICAL MODELLING tic equipment which was facilitated Predicted immissions, Responses to by microchip technology and, in Transport/Dispersion pollutant emissions Chemical transformations some cases, is dependent on biosen­ control strategies sors; and technology for imaging and visualization. Disposable "self-test" kits are now commonly used for the approxi­ mate estimation of blood glucose, for pregnancy tests and for testing of Pollutants, heat, Wind speed, direction , Conce ntrations Man, flora, fauna , dust, humidity etc... turbulence, temperature, local in space and time materials etc ... urine. However, when more precise topography, climatic condit ions determination of concentrations is Computer modelling is a useful tool in many fields of medicine. This example shows the needed, biosensor technology will concentration of industrial pollutants under certain climatic conditions which ma y have an impact become important. Biosensors on health. World Health • 48th Year, No. 3, Moy-June 1995 31 tissue movement. Special techniques • The overall effectiveness of any national health needs and constraints, -e.g., colour display of flow map­ specific medical technology depends in decision support technology, and ping which helps visual interpreta­ on where it is needed and on how and in the design of project management tion, and pulsed Doppler which through what system structure it is to techniques. Such multidisciplinary measures both range and velocity, be operated, so that strategic plan­ research advances should not be thus allowing velocity profiles to be ning for the introduction and use of overlooked by health planners: not examined -are adding complexity, this technology is important. least in developing countries where but are also likely to expand the Planning the best use of technology limited resources have to be range of investigations. within an overall national or regional stretched as far as possible. • health care plan requires the consid­ Relevance to health care eration of very many factors. Since Or Boutros G. Mansourian is Director, O ffice of human planners cannot easily take Research Policy and Strategy Coordination, There are two respects in which World Health Organization, 12 I I Geneva account of the numerous relevant 27, Switzerland. Professor Bruce MeA. multidisciplinary research is a potent data that bear upon choices, there is a Sayers, former Dean of the Imperial College of source of support for health care. need for special computer-based Science, Technology and Medicine, is Director • Within the particular field of of the Centre for Cognitive Systems, W illiam tools to help acquire and analyse the Penney Laboratory, Imperial College, London. medical radiology, for example, both essential information, decide on SW7 2AZ, Englan d. materials technology and computer resource allocations, and design technology have much to offer. organizational structures for the best Photo Credits Thus, the impending development of use of this technology, with plans on Covers: Design by WHO. Photos courtesy of: lnstitut fUr higher temperature superconducting Klinishe Radialagie- Rontgen diagnastik - MO nster, how to introduce them. Further­ Germany; Department of Radio logy, Un iversity of materials will simplify and render Tokyo Faculty of Medicine. more, training of personnel may have Page 3: WHO/ Centre Antoine Beclere, Paris; cheaper the costly magnets used in to be planned and implemented and WHO/ H. Anenden magnetic resonance imagers. At the Page 4: Courtesy of the Americon College of Rad iology job descriptions devised. Monitoring archives, Reston; USA © level of manufacture, high-strength of performance may have to be Page 5: Archives Curie et Jaliot Curie, Paris© light-weight composite materials Page 6: WHO/ D. Gibson arranged with a view to identifying Page 7: WHO/ G. Hanson could help to reduce the weight and the need for further training or cor­ Page B: WHO/ H. Anenden bulk of complex equipment, making Page 9: Courtesy of the Hu ngarian Institute of Cardiology, recting mismatches between job Buda pest © their transport in the field easier. descriptions and the actual require­ Page 10: WHO/ H. Anenden; WHO / Seiichi Higa Computer technology, coupled with Page 11: WHO/ Regional Medicol Physics Department, ments. Newcos~e upon Tyne, UK the technology of digital signal Page 12: WHO/T. Holm; WHO/G. Hanson Page 13: WHO/ H. Anenden processing, is progressively improv­ Much of this effort has to be based Page 14: Radiological Society of North America, Radiographies ing the methods for interpretation of on the insight and experience of 1989; 9:723-7 64/C. Viborny © Page 15: L. Sirman © medical images, both through techni­ experts, planners and consultants Page 16: WHO/F. Ben Chehido cal developments in image enhance­ who know the country, its systems Page 17: WHO/F. Jangheerkhan Page 18 & 19: WHO/Derortment of Radiology, University of ment and by incorporating and using and its culture well. As their experi­ Tokyo faculty o Medicine semantic information that encapsu­ ence and knowledge are often Page 20: L. Sirman © Page 21: Courtesy of the Centre Georges·Fran1ois led ere, lates the experience of expert ob­ encapsulated in statements, both Dijon ©; L. Sirmon © Page 22: WHO/A. Anenden servers. Another imaging technique "knowledge engineering" and the Page 23: WHO/ J. lindmark has also recently evolved from re­ techniques of computational logic Page 24: WHO/ Arias &Skvarca Page 25: WHO/ Arias & Skvarco; WHO/ H. Anenden search in combination of materials, are needed to make use of this Page 26: l. Sirman computing and signal processing; resource. Potentially valuable Page 27 : Courtesy of: BiomogneticTe chnologies, San Diego, USA ©; Dr Ferencz, Brigham & Women's Hospital, this ultrasonic examination technique developments are taking place in Harvard Medicol School, USA ©; Dr Brook RJeffre y, evaluates the state of the walls of information technology, in the acqui­ Stonford University, USA © Page 28 & 29: L. Sirrnan arteries and promises improved early sition and use of "knowledge" as Page 30: Courtesy of Victor lebessis, EPFL, lausanne, distinct from "data" in interpreting Switzerland © recognition of developing atheromas. Backcove r: L. Sirman

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