MONDAY, 11/29/99 ~ EVENING EDITION
Investigational MRI technique identifies soft plaque in arteries

BY BRENDA TILKE

An investigational MR technique may prove to be an important tool for identifying soft plaque in the coronary arteries, which is associated with 70% of heart attacks.

Using a modified high-field dedicated cardiac MRI scanner, researchers at Mt. Sinai School of Medicine in New York City have developed a method for examining and classifying plaque in the coronary arteries.

"The only other technology that can actually look at the type of plaque on the walls of the arteries is intravascular ultrasound (IVUS), which is invasive-and the pictures are not nearly as good," said Dr. Zahi A. Fayad, director of cardiovascular imaging, physics, and research at Mt. Sinai.

 
Dr. Zahi Fayad explains research findings based on use of high-field cardiac MRI scanners to classify coronary artery plaque.

In the Mt. Sinai study, 13 subjects underwent the modified MR scanning. Of these, eight were healthy controls (college students between 18 and 25 years of age), and five were patients in whom heart disease had been detected with conventional angiography. In patients with blockages of 40% or more, the plaque buildup was up to 10 times thicker than in the healthy control group. Moreover, many of the patients had bulging plaque that could potentially rupture. Soft plaque has a high lipid content.

The MR technique was able to visualize the shape of the plaque inside the arteries, according to Fayad. In one patient with adequate blood flow, identification of the dangerous plaque led to a change in treatment. The technique holds great promise for improving evaluation and assessing the success of intervention, he said.

"MR also might be used to assess whether treatment is working and to help determine whether other measures need to be taken," Fayad said. "It also may tell us when the plaque is stable and that perhaps in some cases, no therapy is needed."

The study is being expanded to include up to 20 patients.