CHICAGO (Reuters) – Newer CT technology that can capture an image of a beating heart in a single beat may offer one way of reducing a patient's exposure to excess radiation, US researchers said yesterday. They said patients who got a type of heart scan called coronary angiography using the newer CT scanner technology received 91 percent less radiation than those who were scanned the traditional way using a computed tomography or CT scanner.

"The amount of radiation that a patient would receive is about a 10th of that as compared to using the most traditional protocol," Dr. Andrew Einstein of Columbia University Medical Center in New York, whose study appears in the journal Radiology, said in a telephone interview.

Radiation exposure from medical scans became a major concern of patients and lawmakers last fall after more than 200 patients were exposed to excess radiation during brain scans at Cedars-Sinai Medical Center in Los Angeles. Although heart CTs only accounted for 2.3 million out of 65 to 70 million CT scans performed in 2006, they are worrisome because they deliver high radiation doses, Einstein said. "Since these are relatively high-dose tests, the ability to reduce the dose is a good thing," he said.

Heart CTs offer a noninvasive way to look for blockages in heart arteries. Traditionally, most of these patients get an angiogram, in which a thin tube is inserted into heart arteries but not all patients are good candidates for this.

Einstein and colleagues wanted to see how newer scanners that can capture a heart beat in a single scan compare to older, more time-consuming methods in terms of radiation dose.

For the study, he used the Toshiba Aquilion ONE scanner, which has the single heart beat feature but can also do conventional CT scans in which the scanner spirals around a patient.