Computed tomography and radiation: understanding the issues.

We are currently seeing increasing opportunities to improve patient care with computed tomography (CT). At the same time, we are challenged to use this technology wisely. In particular, we are being asked to balance the benefits against the risks, chiefly those of ionizing radiation. To do this, we must have a foundation from which to determine the relative risks. This foundation necessarily must be composed of several components. First, it is important to understand the patterns of use and increasing application of CT, particularly multidetector CT. In addition, it is helpful to be familiar with measures of radiation pertinent to CT and the doses provided by this modality. This foundation then provides a context in which to discuss the issue of low-dose radiation and cancer risk as well as potential changes in CT practice guidelines and regulation. It is with an understanding of these issues that radiologists and other radiology personnel can participate in an informed discussion with referring physicians and patients and continue to optimize the practice of CT.