CT More Accurate than MRI for Ruling out CAD

February 2, 2010 - Among noninvasive imaging tests for ruling out coronary artery disease (CAD), computed tomography (CT) is a more accurate noninvasive test than magnetic resonance imaging (MRI), according to a comparative study released in Annals of Internal Medicine.

CAD is a major cause of death in the United States. Typically, CAD is diagnosed through conventional coronary angiography. However, this technique is invasive and potentially risky. As multislice CT and MRI have become more widely adopted for noninvasive coronary angiography, researchers wanted to compare CT and MRI for ruling out clinically significant coronary artery disease CAD.

Researchers reviewed studies that compared CT (89 studies) or MRI (20 studies) to conventional coronary angiography in patients with suspected or known CAD. The studies were comprised of 7,516 and 989 patients, respectively. The researchers found that for ruling out CAD, CT is a more accurate noninvasive test than MRI.

It is important to note that only a few of the studies investigated coronary angiography with MRI. Only five studies were direct head-to-head comparisons of CT and MRI. Covariate analyses explained only part of the observed heterogeneity.

The investigators concluded that for ruling out CAD, CT is more accurate than MRI. Scanners with more than 16 rows improve sensitivity, as do slowed heart rates.

Reference: Schuetz, G; Zacharopoulou, NM; Schlattmann, P; Dewey, M.Noninvasive Coronary Angiography Using Computed Tomography Versus Magnetic Resonance Imaging. Annals of Internal Medicine. Feb. 2, 2010 152:167-177.

For more information: www.annals.org