Research on MRI screening for coronary artery disease
New imaging technique may lead to early screening of coronary artery disease.
Balintfy: Coronary artery disease is the most common type of heart disease and is the leading cause of death in the United States. Coronary artery disease happens when the coronary arteries — those are the blood vessels that supply blood to heart muscle — become hardened and narrowed. This is due to the buildup of cholesterol and other material, called plaque, on their inner walls. Plaque buildup in the arteries can lead to serious problems, including heart attack, stroke, and even death. Researchers are now investigating a new way to look at these arteries before any symptoms of coronary artery disease appear.
Gharib: It's almost like trying to image spaghetti on a trampoline.
Balintfy: Dr. Ahmed Gharib at the NIH explains capturing images of the blood vessels of the heart is a challenge.
Gharib: The problem with looking at the vessels that supply the heart is, as you can imagine, it's a smaller vessel — it's about 2 mm — and it's sitting on moving organ which is beating at least 60 to 90 beats per minute which is also sitting on the diaphragm which is what we use to breathe.
Balintfy: But results of a study using magnetic resonance imaging or MRI technology are promising. Dr. Gharib says the new technique is almost cinematic in the way it can capture one still image that is close to perfect.
Gharib: It's almost like imaging a race car — and it's moving very fast — so if you take one shot at it, your chances of success is less than if you or take multiple shots at it. Your chances of getting an image with less blur increases.
Balintfy: Researchers have used the MRI technique to measure the thickness of coronary artery walls in 26 patients who have at least one risk factor for coronary artery diseases. They also measured 12 patients with no risk factors.
Gharib: We found that this technique is quite successful not only in imaging them but also is sensitive and more precise in separating the two groups.
Balintfy: Dr. Gharib points out that other imaging techniques involve some risk, including exposure to radiation, whereas this MRI-based option has virtually no risk at all.
Gharib: You can just go in the scanner and there's no contrast or dye involved. Itís just simply going and lying down for 30 minutes or so.
Balintfy: Researchers emphasize that currently there is 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. The potential for this technique, says Dr. Gharib, is early screening to directly detect hardening or thickening of coronary artery walls which is a direct measurement of early-stage coronary artery disease.
Gharib: So somebody with risk factors or thinks he has problems in that area might come and look at their vessel wall in their coronary arteries and see if it's thickened or not. At a certain point, if it is thickened then we can say okay this is a little bit above the normal.
Balintfy: Dr. Gharib notes, more research with this technique is needed to better identify exactly what a normal thickness is for coronary arteries. But if validated, another potential use could be to test the effectiveness of a drug or other intervention.
Gharib: Now I can actually see if this is working, if what Iíve done has resulted in improvement in this vessel wall.
Balintfy: For more information on this research, visit www.niddk.nih.gov. For details on coronary artery disease, visit www.nhlbi.nih.gov. And to hear more from Dr. Gharib on this study, listen to episode 172 of the NIH Research Radio podcast. For NIH Radio, this is Joe Balintfy — NIH Turning Discovery Into Health®.
About This Audio Report
Reporter: Joe Balintfy
Sound Bite: Dr. Ahmed Gharib
Topic: coronary artery disease, artery, arteries, blood vessel, heart, heart disease, cholesterol, plaque, image, imaging, MRI, magnetic resonance imaging