Introduction Coronary artery disease (CAD) is a leading cause of mortality worldwide. Coronary CT angiography (CCTA) is commonly used as a non-invasive imaging modality. However, it requires iodinated contrast and has risks from ionizing radiation. Iodinated contrast can be nephrotoxic and renal function is often decreased in elderly CAD patients. Current non-contrast enhanced MRI coronary angiography techniques have long scan times that can be challenging for elderly patients. There is an urgent need to optimize rapid MRI coronary angiography methods.
Compressed sensing (CS) balanced steady-state free precession (BTFE) sequences enable faster scans by undersampling of image signals and optimized reconstruction while reducing motion artifacts and maintaining image quality. However, conventional CMRA usually uses sensitivity encoding where increasing acceleration factors degrades image SNR. This study aimed to explore feasibility of CS-CMRA at 3T and determine the optimal acceleration factor to inform clinical implementation.
Method From June to October 2023, 43 patients with suspected CAD prospectively underwent CS-CMRA (acceleration factors of 4, 6, and 8) at a provincial hospital. Image quality subjective scores and objective coronary-myocardial CNR were compared between sequences using Friedman and Wilcoxon signed-rank tests.
Result Scan times for CS4, CS6, and CS8 were 579.4±21.96s, 355.5±13.46s, and 262.4±12.24s (all p<0.0001). Subjective image quality scores showed good agreement (Kappa=0.785, 95%CI 0.758–0.810). Scores for CS4 and CS6 were comparable and higher than CS8 (all p<0.0001). Objective SNR and CNR were similar for CS4 and CS6, both higher than CS8 (all p<0.0001).
Discussion We examined CS acceleration factors 4, 6, and 8 for scan time and image quality. Results show CS6 significantly shortened scan time to facilitate exam completion in elderly patients. Image quality slightly decreased compared to CS4 but without statistical difference, improving feasibility with good clinical potential.
Conclusion 3T CS-CMRA is feasible with CS6 balancing coronary image quality and faster scans benefitting elderly patients.

Acknowledgements

Thanks to Professor Lu Guangming and Professor Jin Dongsheng for their guidance, and to Philips for their support.

References

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