Entries in CT Scans (2)


CT Scan Use Triples in 15 Years; Radiation Risk Justified?

Hemera Technologies/Thinkstock(SAN FRANCISCO) -- The use of CT scans has tripled in the last 15 years, a new study found, which means the average American is exposed to twice as much radiation from medical imaging as in the mid-1990s.

The study, published Tuesday in the Journal of the American Medical Association, found the rate of CT scans per 1,000 American adults rose from 52 in 1996 to 149 in 2010 -- an annual growth of 7.8 percent. And experts say the added imaging may not be improving the quality of care.

"There has been the sense that the use of imaging is a panacea to answer questions and as a result, patients and physicians are really drawn to all kinds of imaging," said study author Dr. Rebecca Smith-Bindman, a professor of radiology at the University of California, San Francisco. "While imaging is outstanding in many clinical settings and truly improves patient outcomes, in other settings it is used without improving care at all."

The use of magnetic resonance imaging (MRI) and ultrasound also increased, according to the study. But those tests are not associated with radiation exposure.

Smith-Bindman spoke on June 8 about the safety of medical imaging before Congress.

"Some people have worried about the X-rays at our airports to screen passengers," she said in her testimony. "One CT scan is equal to approximately 200,000 airport screens."

Previous research has found that radiation from CT scans, which provides detailed images of internal organs using much higher doses of radiation than conventional X-rays, can lead to the development of cancer. And many patients receive multiple CT scans over time, compounding the risk.

Dr. Eric Larson, the executive director of the Group Health Research Institute in Seattle, said, "Hardly a person gets out of an [emergency room] visit without a CT."

"For patients, doctors and others to realize that this may be increasing the rate of cancer is really important," Larson said.

In children, the cumulative dose of two brain CT scans triples the risk of brain cancer and leukemia, according to a study published June 7 in The Lancet. But experts agree that if a scan is clinically justified, the benefits far outweigh the risks.

"The increased health risk associated with increased use of radiation procedures is not of concern as long as it is accompanied by an equal or greater health benefit for the patients," said Dr. Tim Jorgensen of the department of radiation medicine at Georgetown University Medical Center.

Smith-Bindman said patients should ask their doctors if a CT scan is really necessary and find out how it will help their care. They should also make sure the doctor is using the lowest possible radiation dose.

The message for doctors ordering these tests is also clear, Smith-Bindman said.

"We need to treat our patients as partners, who need to understand both the benefits as well as the [harm] from imaging so that they can make informed choices," she said. "In general, patients make good decisions when they are given accurate information."

Copyright 2012 ABC News Radio


CT Scans in Kids Linked to Leukemia, Brain Cancer Risk

iStockphoto/Thinkstock(BETHESDA, Md.) -- Gina Baker carefully weighed the pros and cons of a CT scan for her 1-year-old son.

"His pediatrician said she wanted to do a scan to make sure everything was OK," said Baker, explaining concerns that "the little guy's" head was growing too quickly. "They told me the risks from the radiation were low, but you definitely struggle with those types of decisions as a parent."

The scan came back normal, giving Baker some peace of mind. But Baker, a 31-year-old nurse and blogger from Brigham City, Utah, said she still worries about the test's long-term effects -- a fear bolstered by a new study linking childhood CT scans to cancer later in life.

"Radiation exposure from CT scans was associated with an increased risk of brain cancer and leukemia, and that risk increased with increasing levels of radiation exposure," said Amy Berrington de González, a radiation epidemiologist at the National Cancer Institute in Bethesda, Md., and co-author of the study published Wednesday in The Lancet.

The study, of more than 355,000 children and teens in the U.K., found those exposed to 60 milligrays of radiation -- the cumulative dose of two brain CT scans -- were three times more likely to develop brain tumors. Those exposed to 50 milligrays of radiation were three times more likely to develop leukemia, a cancer of the white blood cells produced in the bone marrow.

Berrington de González stressed that the absolute cancer risk is very small, accounting for one extra cancer case per 30,000 children scanned.

"Providing the scan is clinically justified and performed properly with a child-size dose of radiation, the benefits should easily outweigh the risks," she said.

But for parents like Baker, forced quickly to weigh the immediate benefits with the long-term risks, the decision weighs heavily.

"You want to do what's best for your family," she said. "I did agonize over it."

Radiation has long been known to cause DNA damage that can lead to cancer. But the cancer-causing effects of doses doled out during CT scans were purely theoretical.

"Those estimates drew a lot of controversy because they were based on the cancer risk in atomic bomb survivors," said Dr. David Brenner, director of Columbia University's Center for Radiological Research and lead author of the 2001 study estimating the cancer risk from CT scans. "There was debate about whether the risks were real, and this study shows pretty unequivocally that they are."

But Brenner said the benefits of CT scans, namely their ability to quickly detect life-threatening problems and guide life-saving surgeries, indeed outweigh the risks.

"All medical procedures have risks and benefits," he said. "That said, there are situations where CT scans are being used too much."

Brenner estimates some 20 percent of the country's 80 million CT scans each year are either unnecessary or could be replaced by a radiation-free ultrasound or MRI.

"That's why we need basic guidelines; decision rules that determine when a CT scan is medically appropriate," he said, adding that such guidelines already exist but are not always used.

Dr. Andrew Einstein, director of cardiac CT research at Columbia University Medical Center in New York City and author of an editorial accompanying the study, said he hopes doctors will think twice before ordering CT scans in children, and parents will ask about alternatives.

"I think we need to redouble our efforts to ensure patients are getting appropriate tests with the lowest radiation dose possible," he said. "There are good reasons to use CT scans; it's a lifesaving test for many people. But with every good thing in medicine, there's a potential downside. And for CT scans it's the radiation."

Copyright 2012 ABC News Radio

ABC News Radio