Time-dependence in Tensor-Valued Encoding in Ex Vivo Rat Heart

Tensor-valued encoding is a promising technique for improving specificity in assessing the myocardial microstructure, but can be confounded by time-dependent diffusion (TDD). Here, the influence of TDD on q-space trajectory imaging (QTI) was examined in ex vivo rat heart, using 17 diffusion encoding waveforms with different frequency content and b-tensor shapes. We report apparent over/underestimation of QTI parameters when waveforms had different sensitivity to TDD, and demonstrate a means of frequency matching that reduced the apparent bias. Acquiring QTI at higher frequencies may provide greater sensitivity to intracellular structures, complementing QTI at lower frequencies.