0 T Coronary Magnetic Resonance Angiography in Calcified Coronary Arteries: Diagnostic Performance Compared With Computed Tomography Using Invasive Angiography as Reference

Background Coronary computed tomography angiography (CCTA) often overestimates stenosis in calcified plaques due to blooming artifacts. The performance of 5.0 T Coronary MR angiography (CMRA) in calcified arteries remains unclear. Purpose To assess plaque effects on 5.0 T CMRA image quality and compare diagnostic performance with CCTA. Study Type Prospective. Population Forty‐six patients with suspected coronary artery disease. Field Strength/Sequence 5.0 T; free‐breathing, non‐contrast 3D gradient‐echo sequence, Dixon water‐fat separation, artificial intelligence‐assisted compressed sensing. Assessment Three blinded radiologists with 6, 8, and 12 years' experience independently evaluated all datasets. Obstructive stenosis was defined as ≥ 50%; CMRA and CCTA image quality used a 4‐point scale; quantitative CMRA measures included vessel edge sharpness (VES), signal‐to‐noise ratio (SNR), and contrast‐to‐noise ratio (CNR). CCTA assessed plaque composition, calcium burden, and calcification length. Invasive angiography was the reference. Statistical Tests Diagnostic metrics and generalized estimating equations evaluated performance and plaque–image‐quality associations. Wilcoxon tests compared visual scores. Agreements used Cohen's κ, Fleiss' κ, and intraclass correlation coefficients. Results 5.0 T CMRA showed higher specificity (90.1% vs. 77.7%, p < 0.001) and accuracy (89.4% vs. 82.8%, p = 0.006) than CCTA, with similar sensitivity (88.7% vs. 87.7%, p = 0.740). For CMRA, VES was lower in segments containing mixed plaques than in noncalcified or calcified plaques (16.0 ± 0.8 vs. 18.2 ± 0.8 and 18.3 ± 1.0; p < 0.001). Visual scores differed across calcium‐burden categories (3.35 ± 0.07, 3.16 ± 0.09, 2.96 ± 0.09, and 2.79 ± 0.09; p < 0.001). Greater calcification length was associated with lower VES (B = −0.152, p = 0.008) and visual scores (B = −0.019, p = 0.019). Data Conclusion In this cohort, 5.0 T CMRA showed higher specificity and accuracy than CCTA, with similar sensitivity. Plaque characteristics were associated with selected CMRA image‐quality measures. Evidence Level 2. Technical Efficacy Stage 2.