Alarm about computed tomography scans is unjustified

To the Editor: We agree with Mendelson and colleagues1 about the need to ensure radiation doses of computed tomography (CT) are as low as reasonably achievable while maintaining diagnostic quality of the images. Perceived benefit to the patient must be balanced against theoretical small risks from the procedure. The uncertainty surrounding risk estimates at the lower end of the radiation dose range means that it is important for radiologists to take responsibility for monitoring radiation dosimetry. This becomes especially important when imaging young people with chronic disease (such as renal calculi, chronic hepatitis, cystic fibrosis and inflammatory bowel disease), who may have many CT scans while young. As stated by Mendelson et al,1 the theoretical risks are assumed to be cumulative over a lifetime, but diminish significantly the older the person is at time of exposure.