Strategies found to halve heart CT radiation dose

* Findings could make heart CT scans safer

* Lower dose CT scanners under development

By Julie Steenhuysen

CHICAGO, June 9 (Reuters) - U.S. researchers have found a way to cut the radiation dose from a heart CT scan by half without sacrificing the quality the scan, a finding that could speed adoption of such tests, they said on Tuesday.

Using computed tomography -- or CT scans -- to find heart disease allows doctors to see diseased arteries without having to do a more invasive angiogram, which involves threading a catheter through heart arteries.

"It's becoming increasingly popular as well as increasingly accurate as they develop better and better machines," said Dr. Gilbert Raff of William Beaumont Hospital in Royal Oak, Michigan, whose study appears in the Journal of the American Medical Association.

"You can actually see the arteries that cause heart attacks," Raff said in a telephone interview.

But recent studies have raised alarm about the scans, which expose patients to double, triple or quadruple the radiation exposure of an angiogram, raising cancer risks.

For people living in the United States, Raff said the normal expected radiation dose from chemicals in the ground or flying in an airplane is 3 milliseverts a year.