A survey of the benefits and risks in the practice of radiology.

The findings from both animal and human studies on the radiation risk at low doses and low dose rates are far from conclusive, primarily due to statistical limitations. However, to arrive at some estimate of radiation risk, a conservative approach has been taken, and a linear extrapolation of radiation effects from high doses to low doses has been made. Thus, it is assumed that any exposure to radiation carries some risk of somatic or genetic damage and that there is no threshold or safe dose. In medical practice, diagnostic radiological procedures should be performed only if useful clinical information will be derived. In addition, this information should be obtained at the least possible risk to the patient. For mass chest X-rays, mammography, and lung scans, a quantitative determination of benefit to risk is developed. This approach, though possible desirable, is exceedingly difficult to establish for most diagnostic radiological procedures. Thus, good clinical judgement should be employed in radiological practice, just as it should be employed in all aspects of medical practice.