CHICAGO, NOV. 26 -- Computer-enhanced X-rays are showing promise in rapidly detecting coronary artery disease in people under 60 without requiring the insertion of catheters or other equipment into the body, radiologists reported at a meeting here today.

A technique called ultrafast computed tomography (CT) that uses enhanced X-ray images to detect calcium in arteries could be highly accurate and cost-effective in detecting coronary artery disease, the doctors reported.

"Ultrafast CT appeared to be able to rule out significant coronary artery disease in 100 percent of the cases we studied," said Dr. Jerome Breen of the Mayo Clinic in Rochester, Minn.

He presented the results of a preliminary study of the new test at the 76th annual meeting of the Radiological Society of North America, which began today.

Ultrafast CT was performed on 100 patients between the ages of 23 and 59 who were sent to specialists for coronary angiograms, primarily because of symptoms such as chest pain or chest tightness that suggested coronary artery disease, Breen said.

An angiogram requires that an artery, usually in the groin, be punctured and a tube threaded up through the abdomen and chest into the arteries that supply the heart. An X-ray dye is then injected into these arteries and X-rays are taken of them.

The accuracy of the new test was determined by comparing its results to those of angiograms taken on each of the patients, Breen reported.

"In every case in our study, if no calcium was detected on CT, there was no significant coronary disease seen on the angiogram," Breen said. Significant disease is defined as blockage that obstructs at least 50 percent of the opening of one or more coronary arteries.

"Ultrafast CT is exquisitely sensitive at detecting the presence of calcium in the arteries, a sign of atherosclerotic disease," Breen said.

Atherosclerosis is a buildup of patchy deposits that can clog arteries and may lead to heart attacks.

Dr. Daniel Mark, a cardiologist at Duke University Medical Center, said the test sounds promising but will require further study.

He added that many heart patients are over 60, when calcium begins to appear in the arteries as a normal sign of aging, limiting the test's usefulness in that age group.

Breen emphasized that his results were preliminary, and he said researchers should study more patients before the test's usefulness is established.