Radiation dose in computed tomography: why it's a concern and what you can do about it

Computed tomography (CT) has become an invaluable and even life-saving diagnostic tool. But its great benefits come at a price: Because it uses ionizing radiation, CT can cause cancer. In fact, in the United States alone, it is estimated that CT accounts for around 6,000 additional cancers per year, with about half of those proving fatal. Unfortunately, this risk is not as widely recognized as it should be. In particular, both clinicians and patients tend to lack a clear understanding of the radiation doses involved in CT studies, which are higher than those used in other common x-ray studies. Given the swiftly growing use of CT, there's the real possibility that patients' exposure to radiation will grow as well. Thus, it's vital that clinicians understand the doses involved in CT, that those doses be kept as low as possible, and that CT be used only when the clinical benefits justify it. In this article, we explain the radiation risks of CT and discuss how they compare with other risks in and out of healthcare. We also discuss ways in which the doses delivered to patients can be kept to the necessary minimum. The approaches we cover include eliminating unnecessary CT use, raising referring physicians' awareness of the problem, considering alternative technologies, using good quality assurance, and optimizing imaging protocols.