Tractography

Tracking of DTI and STSRI eigenvectors v ₁, v ₂ and v ₃ was performed in the whole heart using Diffusion Toolkit [41]. Here we refer to ‘tracks’ as streamlines connecting contiguous tensors with similar alignment. Tracks were generated from all voxels within the segmented heart volume, using a 2^nd order Runge–Kutta method, spline filter, an angle threshold of 30° and no FA threshold. A minimum length threshold of 0.5 mm was used for v _1,DT/v _3,ST tracks. Tracks are displayed in the whole heart and in a mid-ventricular short-axis slice using Trackvis [41], and colour-coded by orientation: apico-basal (red), anterior-posterior (green) and lateral-septal (blue).