FROM THE CBS EVENING NEWS -- There were about 70 million CT scans performed in United States in 2007 - up from just 3 million in 1980. The scans, also known as CAT scans can help doctors identify tumors and internal injuries among many other uses.
But they rely on dangerous radiation to get the job done and the harms may be greater than previously thought, reports CBS News medical correspondent Dr. Jon LaPook.
After Alabama school teacher Becky Coudert had a brain CT scan in September her hair started to fall out and, according to a lawyer, "She developed a broad band of baldness from one temple to the other, from around the back of the head."
Her lawyer says she received a higher than normal radiation dose. Two other patients have come forward with similar stories. In Los Angeles, Cedars-Sinai Medical Center is being investigated for giving excess radiation to more than 250 patients during their CT scans.
The problem of too much radiation during CT scans may be more widespread than anyone thought.
"The doses are actually higher than are generally reported," said Rebecca Smith-Bindman, a professor of radiology and biomedical imaging at the University of California San Francisco
New research out today found a wide variation in radiation dose for the most common CT scans, like abdomen, pelvis and chest. A survey of four hospitals found some patients received 13 times more radiation than others for the same type of scan.
"Depending on where a particular patient is sent - hospital one or hospital two - or if he goes in the evening, the dose that the patient received would have been profoundly different and that degree of variation is what was so surprising," Smith-Bindman said.
And just how dangerous is the extra radiation?
"The risk is not huge but it's definitely real," she said.
Radiation is a known carcinogen, even in the relatively small amounts used with most CT's. There are a number of uncertainties involved in predicting cancer risk. But a second study today estimates that about 29,000 future cancers might be caused by the 72 million CT scans done in 2007.