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

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.

To assess plaque effects on 5.0 T CMRA image quality and compare diagnostic performance with CCTA.

Prospective.

Forty-six patients with suspected coronary artery disease.

5.0 T; free-breathing, non-contrast 3D gradient-echo sequence, Dixon water-fat separation, artificial intelligence-assisted compressed sensing.

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.

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.

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).

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.

2.

Stage 2.