Coronary MR is strongest modality
The current advances in coronary MR (CMR) make it the strongest modality for coronary imaging, according to Michael McDonnell, MD, associate professor of the cardiovascular institute at Stanford University School of Medicine. McDonnell presented his thoughts on the modality during a lecture series, “The Latest Advances in Cardiovascular MRI,” this week at the Transcatheter Cardiovascular Therapeutics conference in Washington, D.C.

He said that current cardiac imaging is effective with coronary anomalies, coronary aneurysms, most bypass graft patencies and to assess for ischemic versus cardiomyopathy (CMP), but not effective for whole-heart coronary artery disease and whole-heart coronary plaque.

He said that CMR remains the better modality because it uses no radiation and no contrast. It is “optimal for younger patients,” and it provides an “optimal myocardial assessment,” McDonnell said.

In determining ischemic versus non-ischemic CMP, McDonnell cited a multi-center coronary MR angiography (MRA) trial, which had 109 patients with proximal coronary artery disease. He reported that the combined assessment of the left main and three-vessel disease had an assessment rate of 100 percent.

When McDonnell weighed the differences between CTA and MRA, he determined that patients with a high-calcification rate (about 71m) respond well or image well with CMR. For coronary MRA at 3T, which McDonnell defined as “real-time, you can see it as you scan,” the signal-to-noise ratio is between 40 and 50 percent.

McDonnell also said that other techniques, such as 32-pchannel coil and parallel imaging, help “spatial resolution and provide good imaging.” He highlighted contrast-enhanced whole-heart MR at 3T as providing “significant improvement in contrast to noise.”

In conclusion, McDonnell said that CMR provides better spatial and whole-heart resolution.