ABSTRACT Purpose To evaluate a third‐order motion‐compensated spin echo (M3‐MCSE) sequence at multiple cardiac phases on a clinical 3 T MRI scanner with ultra‐high performance (UHP) gradients (200 mT/m), compared with stimulated echo acquisition mode (STEAM) and second‐order MCSE (M2‐MCSE) for cardiac diffusion tensor imaging (cDTI). Methods Twenty healthy subjects underwent mid‐ventricular short‐axis cDTI at peak systole and diastasis using STEAM, M2‐MCSE, and M3‐MCSE. cDTI metrics and image quality were compared. In five additional healthy subjects, diffusion‐weighted images were obtained at multiple trigger delays distributed over diastasis to assess motion‐induced signal loss. Results Compared to M2‐MCSE, M3‐MCSE yielded higher systolic helix angle map scores () but lower diastolic scores (), with no significant difference in mean diffusivity, fractional anisotropy, helix angle transmurality or sheetlet angle in systole/diastole. STEAM‐derived apparent diffusion coefficients (ADC) were consistent across diastasis, while ADC for MCSE sequences increased at sub‐optimal trigger delays. Conclusion UHP gradients enabled in vivo evaluation of M3‐MCSE, showing superior systolic cDTI but reduced diastolic performance versus M2‐MCSE due to reduced signal‐to‐noise ratio and a longer motion‐sensitive window. Future work may consider numerically optimized gradient designs to enhance MCSE robustness throughout the cardiac cycle.
Wen et al. (Wed,) studied this question.