OBJECTIVES: The purpose of this research was to compare the diagnostic accuracy of three-dimensional navigator-gated magnetic resonance(MR) imaging and 16-slice multidetector row computed tomography(MDCT) versus quantitative coronary angiography(QCA) for the detection of coronary artery stenosis in patients. BACKGROUND: Both MR and MDCT are novel non-invasive tests, which have been proposed for noninvasive detection of coronary artery disease. Yet their diagnostic accuracy has not been directly compared in the same population. METHODS: Fifty-two patients underwent coronary MR and 16-slice MDCT before invasive coronary angiography. Diameter stenosis(DS) severity in vessels >1.5-mm reference diameter were graded visually and measured quantitatively on both MR and MDCT images. Diagnostic accuracy of both methods was compared using QCA as the reference test. RESULTS: According to QCA, 81 of 452(18%) coronary segments with >1.5 mm diameter had >50%DS. By visual analysis,MR and MDCT had similar sensitivity(75%vs. 82%, p=NS), specificity(77%vs. 79%, p=NS), and diagnostic accuracy(77%, vs. 80%, p=NS) for detection of >50 %DS. Quantitative measures of DS by MR(r=0.60, p< 0.001)and MDCT(r=0.75, both p< 0.001) correlated well with QCA. Receiver-operating characteristic analysis demonstrated that quantification of DS severity improved the diagnostic accuracy of MDCT(area under curve AUC 0.81 vs. 0.92, p< 0.001) but not that of MR(AUC 0.78 vs. 0.83, p=NS). CONCLUSIONS: Visual assessment of coronary diameter stenosis severity by MR or MDCT allows identification of significant coronary artery disease with a similar high diagnostic accuracy. Quantitative analysis significantly further improves the diagnostic accuracy of MDCT but not that of MR. OBJECTIVES: The purpose of this research was to compare the diagnostic accuracy of three-dimensional navigator-gated magnetic resonance (MR) imaging and 16-slice multidetector row computed tomography (MDCT) versus quantitative coronary angiography (QCA) for the detection of coronary artery stenosis in patients. BACKGROUND: Both MR and MDCT are novel non-invasive tests, which have been proposed for noninvasive detection of coronary artery disease. Yet their diagnostic accuracy has not been directly compared in the same population. METHODS: Fifty-two patients underwent Coronary MR and 16-slice MDCT before invasive coronary angiography. Diameter stenosis (DS) severity in vessels> 1.5-mm reference diameter were graded visually and measured quantitatively on both MR and MDCT images. Diagnostic accuracy of both methods was compared using QCA as the reference test. RESULTS: According to QCA, 81 of 452 (18%) coronary segments with> 1.5 mm diameter diameter had> 50% DS. By visual analysis, MR and MDCT had simi lar sensitivity (75% vs. 82%, p = NS), specificity (77% vs. 79%, p = NS), and diagnostic accuracy % DS. Quantitative measures of DS severity improved by the QCA. Quantitative measures of DS severity MRF (r = 0.60, p <0.001) and MDCT of the MDCT (area under curve AUC 0.81 vs. 0.92, p <0.001) but not that of MR (AUC 0.78 vs. 0.83, p = NS). CONCLUSIONS: Visual assessment of coronary diameter stenosis severity by MR or MDCT allows identification of significant coronary artery disease with a similar high diagnostic accuracy. Quantitative analysis significantly further significantly improves the diagnostic accuracy of MDCT but not that of MR.