Worried About Getting a CT Scan? Here’s What to Ask Your Doctor

Medical imaging scans that create detailed images of the body’s internal structures are widely used in medicine. Doctors need them to detect and manage certain types of cancer, assess the extent of traumatic injuries, and diagnose and treat many other medical conditions.

But the scans, known as computerized tomography (CT) scans, use x-rays that expose patents to cancer-causing radiation. And there is concern that a diagnostic tool that has become deeply embedded in American medicine is sometimes overused.

A recent study predicted that up to 5% of all cancers would be caused by CT scans, raising questions about when and how the technology should be used. The greatest risk is to infants, since they are growing rapidly and will live for the longest time after the exposure.

Andrew H. Ko, MD, a UCSF professor of clinical medicine and associate chief of the Division of Hematology/Oncology, says CT scans are often the best tool a physician has to evaluate a patient’s symptoms, and the risk of getting them is very modest overall. But patients should feel comfortable asking their doctors if a CT scan is absolutely needed and whether another technology that does not use radiation could be used instead.