Magnetic Resonance Angiography to Diagnose Atherosclerotic Disease

This study will determine the usefulness of magnetic resonance imaging (MRI) for examining the heart or blood vessels. MRI uses a magnetic field and radio waves to produce images of body tissues and organs. The subject lies on a table that can slide in and out of the scanner (a metal cylinder), wearing earplugs to muffle loud noises that occur during the scanning process. MRI of the heart and blood vessels, called magnetic resonance angiography (MRA), is a developing diagnostic method that permits evaluation of arteries and veins without the use of x-rays or invasive catheterization required by conventional angiography. People 18 years of age and older with known or suspected atherosclerotic disease may be eligible for this study. Participants have blood tests and MRA scanning. The MRA takes about 1.5 to 2 hours. During part of the scan, a contrast agent may be injected into a vein to brighten the images of the heart and blood vessels. Subjects are monitored with an electrocardiogram and are asked to hold their breath for about 5 to 20 seconds intermittently during the procedure. A CT scan may be done to confirm the MRA findings. CT uses x-rays to produce pictures of the heart and blood vessels. The subject lies on a bed during the scan and is given a contrast agent through a catheter inserted into a vein. Subjects are asked to hold their breath intermittently for about 5 to 20 seconds. A medicine called a beta blocker may be administered to slow the heart rate.

Magnetic Resonance Angiography (MRA) is a developing technique that permits the non-invasive evaluation of arterial and venous structures without the need for x-ray based catheter angiography. While dramatic progress has been made in the last few years, there are still substantial limitations in the accuracy of MRA in the evaluation of coronary artery. The primary aim of this study is to evaluate state-of-the-art techniques for coronary MRA in subjects with known or suspected coronary atherosclerosis. The secondary aim of this protocol is to generate natural history data for future hypothesis-driven clinical trials using MRA techniques developed in this current protocol. The long-term objective of this pilot study and research initiative is to improve coronary MRA to the point that it can reliably replace diagnostic x-ray catheter angiography in the evaluation of subjects with atherosclerotic disease.