Evaluation and follow-up of patients with urinary lithiasis: minimizing radiation exposure.

As unenhanced computed tomography (CT) has supplanted other modalities (eg, intravenous urography, ultrasonography) as the "test of choice" for evaluation of stone disease, patients have been exposed to higher doses of ionizing radiation in both primary evaluation and follow-up. There has been progressive recognition that low doses of radiation in the range of conventional CT may increase the long-term risk of cancer in exposed patients; these data have been extrapolated from longitudinal and ongoing study of atomic bomb survivors. There have been mounting efforts to develop alternative approaches to conventional CT (eg, low-dose protocols, substitution of ultrasound/plain X-ray) to provide comparable data while reducing total radiation exposure. It is essential that urologists collaborate with radiologists, emergency room physicians, and other providers to appropriately balance the theoretical risks and practical benefits of ionizing radiation in the diagnosis of stone disease.