By IANS,
Toronto : Canadian researchers used 3-D magnetic resonance imaging to pinpoint high-risk bleeding within the walls of diseased carotid arteries, a precursor of stroke.
Carotid arteries are the ones that supply the head and neck with oxygenated blood. The results suggest the technique may prove to be a useful screening tool for patients at high risk for stroke.
“There’s been a major sea change in our research,” said Alan R. Moody, University of Toronto and co-author of the study. “We now know that the composition of carotid artery plaque is likely to be more predictive of future stroke events than the amount of stenosis (narrowing) in the vessel.”
When major arteries are affected by atherosclerosis, fatty deposits, or plaques, accumulate on the inner lining of the vessel walls. Progression of the disease over time leads to narrowing, restricting blood flow or becoming completely blocked.
Until recently, scientists believed that this narrowing, called stenosis, was responsible for most heart attacks or strokes. But new studies have identified the composition of complicated plaques as being a major cause of vascular events and deaths.
These complicated plaques are characterised by surface ulcerations, blood clots and bleeding into the vessel wall.
Researchers performed 3-D MRI on the carotid arteries of 11 patients, aged 69 to 81. Complicated plaques were then surgically removed from the patients’ diseased arteries and analysed under a microscope.
The research team found strong agreement between the lesions identified by MRI as complicated plaques and the microscopic analysis of the tissue samples.
“With high spatial resolution 3-D MRI, we are able to noninvasively analyse the tissue within the artery wall and identify small bleeds within rupture-prone plaques that may put patients at risk for future stroke,” Moody said.
The study will appear in the October issue of Radiology.