From Necessity To Overuse
Some hospitals tend to perform double scans one with a contrast agent and a second without it. Doctors sometimes refuse to accept or are unable to access radiology studies done elsewhere and send patients for duplicate tests at a facility in which they have an ownership interest. Doctors who have a financial stake in radiology clinics or who own scanners use imaging substantially more often than those who don’t, studies have found. And increasingly, specialists are requiring that patients get a scan before they first see a patient.
According to the FDA, which has launched an initiative to reduce unnecessary exposure to medical radiation, the effective doses from diagnostic CTs are “not much less than the lowest doses of 5 to 20 mSv received by some of the Japanese survivors of the atomic bombs” dropped over Hiroshima and Nagasaki in 1945. Some of these survivors have “demonstrated a small but increased radiation-related excess relative risk for cancer mortality.”
Radiation exposure is cumulative, and children, who undergo between 5 million and 9 million CT scans annually, are much more vulnerable to its effects.
Concerns about overuse and potential harm have prompted actions by federal health officials as well as consumer and physician groups. These include the Image Wisely and Image Gently campaigns, as well as the national Choosing Wisely effort, which seeks to educate patients and doctors about unnecessary tests such as CT scans for headaches or back pain.
A “decision support” system that creates a set of standards for doctors to follow, pioneered at Massachusetts General Hospital in Boston, reduced the rate of inappropriate imaging tests from 6 percent in 2006 to 1.5 percent in 2014, said James Brink, the hospital’s radiologist-in-chief. A similar statewide program in Minnesota cut the growth rate from 7 percent per year to about 1 percent annually.
New Medicare rules will require doctors to consider appropriateness criteria developed by the American College of Radiology when ordering imaging. Beginning this year, Medicare will reduce by 5 percent reimbursement for CT scans performed on machines that fail to meet modern standards, including the ability to automatically adjust radiation doses.
But significantly reducing the number of unnecessary CT scans may be an uphill battle.
A recent study found that doctors who order a lot of tests a practice known as defensive medicine get sued less often.
Some radiologists say they spend their days reading scans that trigger a cascade of follow-up tests and procedures for conditions that nearly always turn out to be benign. “I see two or three [incidentalomas] on every scan,” said Jill Wruble, a radiologist at the VA Medical Center in West Haven, Connecticut, who teaches at the Yale School of Medicine. “I never see a normal patient.”