Background: Both whole-heart magnetic resonance coronary angiography (WH-MRCA) and multidetector computed tomography (MDCT) have been proposed for the noninvasive identification of the coronary stenosis. The authors sought to directly compare the diagnostic accuracy of these noninvasive imaging techniques using the invasive quantitative coronary angiography as a reference standard.
Methods and results: Seventy-seven consecutive patients (56 men, 61+/-14 years) prospectively underwent WH-MRCA and 40- or 64-slice MDCT before the quantitative coronary angiography. Diagnostic accuracy of WH-MRCA and MDCT for the visual identification of >50% diameter stenosis in segments of >1.5 mm size was compared using the quantitative coronary angiography as a reference. According to the quantitative coronary angiography, 49 of 992 coronary segments >1.5 mm diameter had >50% diameter stenosis. MDCT had a higher success rate (100% versus 88%, P<0.001) and enabled identification of more segments (963 versus 726, P<0.001) than did WH-MRCA. On a per-segment basis, WH-MRCA had similar sensitivity (47/49 or 96% versus 48/49 or 98%, P=0.9) but significantly lower specificity (644/943 or 68% versus 863/943 or 92%, P<0.001) and accuracy (691/992 or 70% versus 911/992 or 92%, P<0.001) for the detection of >50% diameter stenosis than did MDCT. On a per-patient basis, the sensitivity was similar (17/17 or 100% versus 16/17 or 94%, P=0.9), but specificity (43/60 or 72% versus 53/60 or 88%, P=0.024) and diagnostic accuracy (60/77 or 78%, versus 69/77 or 90%, P=0.044) of WH-MRCA for the detection of >50% diameter stenosis were significantly lower than of MDCT.
Conclusions: Because of the higher success rate and higher number of interpretable segments, 40- or 64-slice MDCT performs better than WH-MRCA.