Can you believe this, which appears in an article in this week's New England Journal of Medicine?
The remainder of the article, by Rebecca Smith-Bindman, MD, of the University of California at San Fransisco, describes the disorganized and dangerous (Ms. C's case is just one of many) state of CT imaging in this country. Dr. Smith-Bindman details the lapses in regulatory and professional oversight associated with CT scanning in the United States--and shares the scary information that although the FDA approves the devices themselves, no group regulates how they are used or what dose of radiation is employed. People who've studied the situation believe that lower doses of radiation can be used in many CT scans without a loss of important diagnostic information, and Dr. Smith-Bindman shows a conventional and low-dose CT to illustrate the point.
Ms. C., a 59-year-old schoolteacher, awoke on September 8, 2009, with facial paralysis. In a local emergency room, she underwent computed tomographic (CT) and magnetic resonance imaging (MRI) brain scanning. The scans were normal, Bell's palsy was diagnosed, and the symptoms resolved over the next few weeks. Two weeks later, Ms. C. began losing her hair in a band-like distribution, and the following week she awoke with vertigo and confusion and returned to the emergency room, where repeat CT and MRI scans were normal. Fatigue, malaise, memory loss, and confusion began soon thereafter and have continued, making it difficult for her to work. Review of the first CT scan revealed that she had received a radiation dose to her brain of 6 Gy — approximately 100 times the dose from the average brain CT scan, 10 times the dose from the average brain-perfusion scan, and 3 timesthe daily dose of radiation treatment for brain cancer. Ms. C. is now a plaintiff in both a federal class-action lawsuit against a CT-scanner manufacturer and a state medical malpractice lawsuit. More than 378 patients in the United States have been identified as having received brain-perfusion scans with similar radiation overdoses, and the Food and Drug Administration (FDA) has issued a national advisory that hospitals should carefully check their CT protocols.
The FDA has (finally) started an initiative to lower diagnostic radiation dosing, and a group called The Alliance for Radiation Safety in Pediatric Imaging kicked off its Image Gently program. (Parents, this is a great web site with lots of resources for you.)
Getting control of CT scan radiation is essential, since even in the best conditions, a CT scan delivers 100 to 500 times the radiation you'd receive from a plain X-ray of a broken ankle, for example. CT scanning can be a lifesaving technology, but it's a potentially dangerous tool and should be used judiciously.