Americans receive the most medical radiation in the world, and the average person's exposure has grown six times over the last several decades. This is a dangerous trend according to medical experts, because overexposure from CT perfusion scans, or CAT scans, can lead to hair loss, burns, and other serious injuries.
Overdoses of radiation can result from too many imaging tests or from technician or machine error. Several recent incidents highlight the dangers of CT brain scans in particular:
So far, the number of patients who have received higher-than-average radiation dosages exceeds 400 at eight hospitals, though the Food and Drug Administration (FDA) says that the actual number of cases is probably higher.
The overdoses were uncovered in the summer of 2009, and after 10 months of investigation, the FDA hasn't issued a final report on what was found. However, a New York Times investigation turned up several findings, one of them being how the overdoses may have occurred.
Officials at Huntsville Hospital, where the largest overdoses were reported, said that the exposure was conducted intentionally to get clearer images. Hospital officials at Cedars-Sinai and Glendale Adventist said that overdoses at their facilities may have been caused by a feature on GE scanners that automatically adjusts the dose based on a patient's size and body part. Officials say that when used with certain other settings, the automatic feature raised radiation doses instead of lowering them.
GE counters that technicians should have known how to safely use the feature and should have noticed dosing levels on treatment screens. Both hospitals argue that the feature was never fully explained by GE technicians, and safety experts say that better designed scanners may have prevented overdoses.
Officials at Los Angeles County and University of Southern California Medical Center and South Lake in Florida, which used Toshiba scanners, said the manufacturer suggested settings that led to the overexposure.
Experts aren't certain of what future health problems may arise in patients who have been overexposed, though cataracts, cancer, and brain damage are possibilities. In addition, there are no federal standards for how much radiation a CT scan should use. Nor is there widespread agreement what constitutes dangerous levels of radiation. In June, the FDA said it's considering a few measures, including:
After reviewing the findings from the New York Times report, the FDA said that is it also considering extending its investigation.