Though CT scans are expensive and pose some radiation danger, their use on patients with minor injuries is rapidly increasing in California.
Between 2005 and 2013, according to University of California, San Francisco and Stanford University researchers, CT use doubled in California emergency rooms for minor trauma injuries.
The researchers, whose findings recently appeared in the Journal of Surgical Research, take no stand on overuse, but point out that physicians should exercise their clinical judgment on when tests are needed and when they’re not.
“We’re not blaming physicians or saying all CTs have been inappropriate,” said study co-author Dr. Renee Hsia, UCSF professor of emergency medicine and health policy. “The culture of ordering imaging studies that we used to think so very carefully about has shifted significantly over the past decade or so. Now CT scans are very easy to get.”
First developed in the 1970s, computerized tomography swept through radiology departments because of its diagnostic power and accuracy. CT scans have largely displaced traditional X-rays.
But doctors also have been criticized for ordering up CT scans when they’re not medically necessary.
The danger of getting cancer from CT scans is small but not insignificant. According to a 2009 FDA report, the risk of developing fatal cancer from a typical CT procedure is approximately 1 in 2,000, although the risk increases with multiple exposures. (The rate depends on what’s being scanned and how many times.)
The researchers analyzed data from more than 8 million adult emergency room visits at 348 state hospitals, collected by the California Office of Statewide Health Planning and Development.
CT scans for minor injuries rose from 3.51 percent in 2005 to 7.17 percent in 2013. Falls were the most common injury among those given a CT scan. The head was the the most common body part scanned.
Among the factors contributing to rising CT use in emergency departments were the increased diagnostic accuracy of CT over x-rays, efficacy of pan-scanning [a wide field-of-view CT] for major trauma, the greater availability and convenience of CT machines in the emergency department, and pressure to shorten patient visits and expedite discharges, the authors wrote. Another factor was pressure to practice defensive medicine to avoid malpractice claims.
Almost every hospital emergency department has a CT scanner, said Hsia, and “there’s lots of pressure not to miss things.”
Awareness is growing about the use of CT scans, she said, citing national advocacy efforts such as the Choosing Wisely campaign that promotes more informed decisions about wasteful or unnecessary medical tests, treatments and procedures.
“I’m not terribly surprised by the study results,” said Dr. Marc Futernick, president of the Sacramento-based California chapter of the American College of Emergency Physicians or California ACEP. “We’ve moved from [x-ray] films to CTs in a number of areas, and it’s just a better test, both medically and legally,” he said.
It is difficult to justify spending the same amount of time on an inferior test, Futernick said. “For example, when I see a patient, who to me meets the threshold for taking a look to make sure there’s no broken bone in the neck, it’s foolish to do an x-ray.”
However, he notes that “clearly CT costs more” and radiation exposure can be dangerous. “We don’t use CT if we don’t need it,” he said. “There is a push currently to do ultrasounds, which have no radiation. Look with ultrasound first, then do CT if you need it.”
Dr. Hsia’s study co-authors were Dr. Kristan Staudenmayer of the Department of Surgery at Stanford University School of Medicine and Gregory Tong, UCSF medical student.