Accelerated free-breathing diffusion tensor MRI of the entire human heart using spatiotemporal registration and retrospective image selection

Excerpt

Currently diffusion tensor MRI (DTI) of the heart can be performed in vivo either with a dual-gated STE [1] or gated motion-compensated PGSE [2]. Both are inefficient due to cardiac and respiratory motion leading to long scan times [3]. Simultaneous multi-slice (SMS) blipped-CAIPI [4] has emerged as a unique EPI technique to acquire multiple slices simultaneously. SMS has been used for cardiac DTI with breath-holding (BH) but with limited coverage [5]. Here, we present a clinically feasible whole-heart free-breathing (FB) accelerated DTI approach by combining SMS with i) sequential acquisition of all repetitions of each direction and ii) spatiotemporal registration (STR) followed by retrospective image selection, avoiding navigator echoes or controlled respiration. Our approach facilitates whole-heart coverage with scan time under 15 minutes, leading to reproducible DTI measurements, and enabling 3D tractography. …