New MRI Technique Detects Early Onset of Coronary Artery Disease

A recent study from the National Institutes of Health (NIH) regarding magnetic resonance imaging suggests that researchers are close to finding a new imaging technique that can identify the thickening of the coronary artery wall, or the early stages of coronary heart disease. The study is published online in the journal Radiology.

"Imaging the coronary arteries that supply the heart with blood is extremely difficult because they are very small and constantly in motion," said lead researcher Khaled Z. Abd-Elmoniem, Ph.D., staff scientist in the Biomedical and Metabolic Imaging branch of NIH's National Institute of Diabetes and Digestive and Kidney Diseases. "Obtaining a reliable and accurate image of these vessels is very important because thickening of the vessel wall is an early indicator of atherosclerosis."

Coronary Heart Disease starts when fat and cholesterol deposits (called "plaques") collect and build up inside of coronary arteries (a condition called atherosclerosis). This increases the risk of a heart attack and other coronary mishaps. If a thickening vessel wall is caught early, intervention is possible.

"We currently have no reliable way to noninvasively image coronary artery disease in its early stages, when the disease can be treated with lifestyle changes and medications to lower cholesterol," Dr. Abd-Elmoniem said.

The researchers used magnetic resonance imaging to measure the wall thickness of the coronary artieries of 26 patients with at least one factor for coronary artery disease (CAD) and 12 healthy control participants. The subjects were matched by their body mass index and the mean age of the patients (which included 13 men and 13 women) was 48. The control study included three men and nine women with a mean age of 26.

To measure the thickness of the coronary artery wall, the researchers used both a single-frame MRI scane and an MRI technique called time-resolved multi-frame acquisition, in which five continuous images are captured in successive order to increase the success rate of obtaining a blur free image.

Using the time-resolved multi-frame acquisition method, the success rate for obtaining a usable image was up to 90 percent, versus the success rate of 76 percent for the single-frame method. The time-resolved multi-frame technique also resulted in a greater ability to detect significant differences between the wall thickness measurements of CAD patients and the healthy participants, along with a smaller standard deviation, which indicates more precise measurements.

"These results suggest that MRI may be used in the future to screen for individuals at risk for coronary artery disease and may be useful for monitoring the effects of therapies," Dr. Abd-Elmoniem said.

"Dr. Abd-Elmoniem is a bright and inventive scientist who first suggested this innovative approach to improving coronary wall imaging," said Roderic Pettigrew, Ph.D., M.D., Director of the National Institute of Biomedical Imaging and Bioengineering (NIBIB) and senior collaborator of the study. "We are delighted that the technique is showing such practical promise."

Abd-Elmoniem says that unlike blood testing that measures the cholesteral and lipids in the blood, which can potentially be indicators of atherosclerosis, the thickness of coronary artery walls is a direct measurement of early-stage CAD.

For more information on the study, visit: http://www.eurekalert.org/pub_releases/2012-10/rson-nmt100312.php