Researchers say the advanced technology provides 3-dimensional images of the heart that can detect reduced blood flow from the heart's main pumping chamber.

Previous studies linked reduced outflow--a measure called left ventricular ejection fraction--to impaired exercise ability and poor prognosis after a heart attack. The Wake Forest University group was able for the first time to take pictures of damage to the lower part of the heart, which normally resembles the point of a football.

Heart attack or disease may cause the heart to lose its usual shape, according to radiologist Dr. W. Gregory Hundley, the leader of the North Carolina research team. In the study, people with such damage had six times the risk of additional heart attacks or heart-related death over the next two years as those with normal scans.

Experts believe MRIs may become widely used for cardiac screening in the future, due to the precise pictures it provides without invasive procedures.