Computed tomography (CT) and magnetic resonance imaging (MRI) are tow imaging techniques that have evolved as non-invasive methods of detecting coronary artery disease, or narrowing of the small blood vessels that supply oxygen and blood to the heart. But, which is better? In the February 2, 2010 issue of Annals of Internal Medicine, researchers report that CT is more accurate than MRI at ruling out coronary artery disease.

German researchers examined studies comparing CT or MRI with conventional coronary angiography in adults with suspected or known coronary artery disease. They analyzed data from 109 studies comprising over 8500 patients and found that CT was more accurate at both correctly identifying coronary artery disease when it was present and ruling out coronary artery disease when it was not present. This was true whether the coronary artery disease was already known to exist or merely suspected. The researchers also found that the patient’s heart rate during CT affected the ability of the imaging study to correctly identifying existing coronary artery disease. CT was better when the patient’s heart rate was less than 60 beats per minute.

A limitation of this analysis was that only 20 of the 109 studies examined assessed MRI as a non-invasive method of detecting coronary artery disease and only 5 of the studies were head-to-head comparisons of CT and MRI. Still, based on this analysis, CT is more accurate than MRI for ruling out coronary artery disease, especially when the scanner has more than 16 rows and the patient’s heart rate is less relatively slow.

Source:

Ann Intern Med. 2010;152(3):167-177