At Vanderbilt, children brought to the ER after a motor vehicle accident used to automatically get an abdominal CT scan. “Now we get liver enzymes first to see if they have a liver [injury] and we need a CT scan,” she said. In the past decade the number of CT scans has been cut by nearly half, she said.
Smith-Bindman said that excessively high radiation dosage is a problem requiring urgent attention. A 2009 study she led found that the actual radiation doses from CT scans varied as much as 13-fold for the same test performed at the same hospital, and these doses were much higher than those required to make a diagnosis. Except for mammography, there are no federal regulations governing radiation doses.
There are several reasons for the variation, Smith-Bindman said, including the failure to adjust the radiation dose based on body size and a desire to achieve more finely detailed images, which can be achieved by ramping up the dose. Nor are there national standards for technologists who administer CT scans, which involve increasingly sophisticated equipment. Some states don’t even require that they be licensed, allowing virtually anyone to operate the equipment.
“There’s no standardization of how these exams get conducted,” Smith-Bindman said. “There’s no oversight and no one’s responsible for this.”
Recently, she said, she spoke to a group of 300 radiology technologists and was “dumbfounded” by their questions. One asked her, “How do I pick a dose?” The technologist said she had devised her facility’s CT protocol, a job that is supposed to be performed by radiologists. Another said that in her hospital, “no one cares” about radiation doses.
Although Jean Hanvik avoided an abdominal CT after her diverticulitis flared, a few months later she had a different experience with a painful wrist. Before an orthopedist would see her, he required that she get an MRI scan, much of which she had to pay for out of pocket. It revealed that she had arthritis. Hanvik wonders why an expensive scan was necessary, particularly before ever talking to the doctor.
“I’m frustrated that diagnostic imaging has become the first line of defense,” she said. “I’m learning to ask a lot more questions.”