Benefits and Risks in Medical Imaging.

Ionizing radiation has contributed enormously to dramatic improvements in medical care. The potential risks of radiation-based medical imaging have, however, drawn considerable attention in recent years. Although such concern is beneficial in terms of critical evaluation and optimization of imaging procedures, it can create the misconception that radiation is the only risk of medical imaging. In contrast to expression of radiation risks, quantitative estimates of the benefits of medical imaging are notably lacking. Expression of benefit in purely qualitative terms vs. expression of risk in quantitative, and thus apparently more concrete, terms may contribute to a biased judgement of the relative benefits and risks of medical imaging among health care professionals as well as the public. This paper, therefore, quantitatively compares the benefits of diagnostic imaging in several cases, based on actual mortality or morbidity data if ionizing radiation were not employed, with the linear no-threshold model derived (i.e., theoretical) estimates of radiogenic cancer mortality and illustrates the large benefit-to-risk ratios typical of medical imaging procedures.