A European study published in the Annals of Internal Medicine analyzed data from previous studies involving multi-slice CT and MRI for ruling out coronary artery disease (CAD) in adults with suspected or known CAD. Based on the compiled data, the most effective modality for ruling out CAD was shown to be CT.

The researchers analyzed over 100 prospective clinical studies and papers that compared CT or MRI with conventional coronary angiography. However, it should be noted that there were very few head to head studies of CT versus MRI; in fact, only five studies directly compared the two modalities.

Nevertheless, an analysis of all the overall data showed that CT had an average sensitivity of 97.2% and a specificity of 87.4%, where as MRI had a mean sensitivity of 87.1% and specificity of 70.3%.

Not surprisingly, CT scanners with more slices (16 or greater) were significantly more sensitive than older scanners. Also, heart rates less than 60 beats/min during CT yielded significantly better values for sensitivity than did higher heart rates.

The authors 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.”

The study is entitled “Meta-analysis: Noninvasive Coronary Angiography Using Computed Tomography Versus Magnetic Resonance Imaging,” by Schuetz, Zacharopoulou, Schlattmann, et al, and is available online.