Today, computers are used in several important and fast-growing medical imaging modalities, such as digital subtraction angiography, positron emission tomography, magnetic resonance imaging, nuclear medicine, and diagnostic ultrasound. The ultimate test for the computer in medical imaging will be its ability to replace traditional film-based radiography as the mechanism for displaying, communicating, and storing imaging information. This transition will require radiologists and other imagers to accept information in digital form. The speed of that acceptance depends on the economic incentives of the health care system. These are changing as a result of cost containment, which is moving away from fee-for-service toward bundled payment. The increase in capitated health plans will encourage the development of digital radiography systems that realistically trade-off the perceived quality needs of radiologists with the costs of producing and operating such systems.

High technology developments in diagnostic imaging raise a number of issues that are disturbing. New developments do not always favor greater diagnostic efficacy since fads, marketing promotion, and entrepreneurs can distort medical goals. New advances disseminate rapidly in affluent societies before formal benefit evaluations are completed. We suggest that digitization of radiography must be critically assessed, and simplicity of equipment design should be promoted. Though medical and economic factors can provide guidelines for policy making, the ultimate priority decisions are political in nature.

Diagnostic imaging in small hospitals is discussed. Four key questions are answered: (1) Are diagnostic imaging technologies necessary at this level? (2) Which technologies should be chosen and why? (3) How can they be most rationally and cost effectively used? (4) How can their total impact on health care be assessed? The paper concludes that small hospitals should have diagnostic imaging facilities and that the modalities of choice are diagnostic radiology and ultrasonography. A detailed description is given of the WHO Basic Radiological System and General Purpose Ultrasonographic equipment together with WHO recommendations for the rational use of diagnostic imaging.

The rehabilitation field has not always been regarded as the most glamorous or commercially promising section of medical care. But changing attitudes and demographics in many industrial countries have led to increased recognition of opportunity to provide services for individuals with disabilities and those in need of chronic care. As hospitals are under increasing pressure to offer rehabilitation services, this article focuses on three different technologies developed in three different countries, Sweden, the United Kingdom, and the United States.

Total joint replacement has restored function and provided comfort to many patients who would otherwise have suffered. However, success and widespread diffusion of this procedure pose a number of important questions. The patient's and the doctor's criteria of success may not be the same: Which are to be used? Health resources are becoming limited: Should money be spent to restore function and for pain relief to those late in life or past their work life? Who makes this choice? A medical technology is tested in the best of settings but routinely practiced in many: How should society and health care professionals monitor the results of surgery? Who should do surgery and where should it be done?

Extracorporeal shock wave lithotripsy (ESWL) for upper urinary stones has been in use in the United States since 1984. It was accepted immediately by hospitals and physicians, and its diffusion has been and continues to be rapid. Government payment and planning policies do not seem to have slowed this diffusion, although they have had some effect on the ownership of lithotripters and the manner in which ESWL is provided. An unintended but foreseeable result of ESWL's popularity with hospitals, physicians, and patients is that ESWL is not only rapidly replacing traditional surgery but is being used on many patients who would not have had surgery. It is likely that many more upper urinary stones are being treated aggressively now than before ESWL was introduced.

Sweden's first, and so far only, ESWL unit for kidney stone treatment became operational on April 1, 1985. This paper presents some intermediate results from an integrated medical, economic, and technical evaluation of the new technology. Seventy-eight percent of 477 patients were defined as successfully treated, totally stone free or fragments less than 4 mm in size, after a follow-up of four weeks. After six months, the share of successfully treated patients had increased to 82%. Successes were closely related to the stone situation; the smaller the stone, the greater success of treatment. Patients' experiences with treatment were also studied and showed that less than 5% of the patients perceived the treatment as unpleasant, frightening, and/or time consuming. Epidemiological data reveal that one unit can replace all open surgical operations on the kidney.

“From a distant vantage the [Mandelbrot] set resembles a squat wart-covered figure eight lying on its side. The inside of the figure is ominously black. Surrounding it is a halo colored electric white, which gives way to deep blues and blacks in the outer reaches of the plane.

Approaching the Mandelbrot set, one finds that each wart is a tiny figure shaped much like the parent set. Zooming in for a close look at one of the tiny figures, however, opens up an entirely different pattern: a riot of organic-looking tendrils and curlicues sweeps out in whorls and rows. Magnifying a curlicue reveals yet another scene: it is made up of pairs of whorls joined by bridges of filigree…, and in the center of these curlicues another version of the Mandelbrot set is found.

The magnified version is not quite the same Mandelbrot set. As the zoom continues, such objects seem to reappear, but a closer look always turns up differences. Things go on this way forever, infinitely various and frighteningly lovely.” (4)

This study assessed the diagnostic utility of two technologies for evaluating respiratory abnormalities in sleep. We compared conventional polysomnography with a new, ambulatory microprocessor technology. Two key features of the comparison involved: (a) the use of multiple, skilled interpreters of each system; and (b) inter-rater agreement within the systems as a crucial test for the diagnostic utility of each. Results indicated that general categories of respiratory abnormalities could be judged more reliably than more specific categories, regardless of technology. For certain categories of respiratory abnormalities, however, inter-rater agreement with the newer technology was extremely low (e.g., reliability coefficients of.12,.09, and –.06). Factors contributing to these low diagnostic reliabilities are discussed. Our data indicate that any assessment of new technology cannot be made apart from the clinical judgments to be rendered with that new technology. This approach may be generalizable to the assessment of other diagnostic technologies.