Optimization of the acceleration of compression sensing in whole-heart contrast-free coronary magnetic resonance angiography.

Background: This study aims to identify optimal acceleration factors (AFs) for compressed sensing (CS) technology to enhance its clinical application for suspected coronary artery disease (CAD) in whole-heart non-contrast coronary magnetic resonance angiography (CMRA).

Methods: Two hundred and seventeen individuals with suspected CAD underwent whole-heart non-contrast CMRA on a 1.5-T CMR scanner with CS AFs of 2, 4, and 6 (CS2, CS4, and CS6). Two radiologists independently and blindly scored the image quality. The overall image scores, coronary artery segment scores, signal-to-noise ratios (SNR), contrast-to-noise ratios (CNR), and scan times were compared. The scores for left anterior descending artery (LAD), left circumflex branch (LCX), and right coronary artery (RCA) were assessed. Of the 217 patients, 37 (17.1%) underwent X-ray coronary angiography (CAG). The images from CS2, CS4, and CS6 were evaluated by two radiologists blinded to CAG results to identify significant luminal narrowing. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated.

Results: The CS2 group exhibited higher overall scores, coronary artery segment scores, SNR, and CNR, but longer scan times compared to the CS4 and CS6 groups (Overall Score: 24.50 vs 22.00 vs 21.00, p<0.001; SNR: 127.23 vs 112.14 vs 99.45, p<0.001; CNRcor-fat: 118.33 vs 101.25 vs 84.17, p<0.001; CNRcor-myo: 69.67 vs 62.83 vs 53.50, p<0.001; Scan Time: 884.2±308.2s vs 472.8±163.0s vs 330.7±145.9s, p<0.001). Proximal and middle segments received higher scores compared to their corresponding distal segments, and the RCA exhibited higher image quality than LAD and LCX in all groups (p<0.05). In the subgroup analysis, 19 (51.3%) were diagnosed with CAD by CAG. The sensitivity, specificity, PPV, NPV, and accuracy were as follows: CS2 (94.7%, 88.9%, 90.0%, 94.1%, and 91.9%), CS4 (89.5%, 94.4%, 94.4%, 89.5%, and 91.9%), and CS6 (89.5%, 66.7%, 73.9%, 85.7%, and 78.4%), respectively, in patient-based analysis.

Conclusion: Image quality showed a decreasing trend with increasing CS AFs, while scan time decreased in non-contrast CMRA. A scanning protocol using CS4 provided high-quality images with relatively short scan times and showed potential for detecting significant coronary stenosis, making it an optimal protocol for coronary magnetic resonance imaging.