Cardiac diffusion tensor imaging in non-ischaemic cardiomyopathy: preliminary insights in myocardial microstructure and functional recovery

Abstract Introduction Non-ischaemic cardiomyopathy (NICM) is a major contributor to heart failure-related mortality and morbidity. Studies have shown that nearly one-third of NICM patients experience functional recovery called left ventricular reverse remodelling (LVRR); however, the underlying myocardial changes remain poorly understood. We sought to investigate myocardial tissue changes in NICM by using diffusion tensor cardiac magnetic resonance imaging (cDTI). Purpose The study aims to compare myocardial microstructural changes as assessed by cDTI among NICM with reduced EF (rEF NICM), recovered EF (LVRR NICM), and healthy volunteers. Methods Twenty-four NICM patients [17 with rEF NICM and 7 with LVRR NICM] and 12 healthy controls (HC) underwent 3T cDTI. The protocol included cine images, tissue mapping pre- and post-contrast, free-breathing spin-echo DTI (3 slices, 18 diffusion directions at b-values 100s/mm2, 200s/mm2 and 500s/mm2 using second-order motion-compensated (M2) gradients, acquired resolution was 2.20*2.27*8mm3 and late gadolinium enhancement (LGE). HC followed the same protocol with no contrast agent. Global analysis yielded mean diffusivity (MD) ( measure the freedom of water diffusion in the myocardium; it has been shown to increase in interstitial fibrosis and/or oedema), fractional anisotropy (FA) (a measure of directionality of water molecules; abnormalities are related to collagen infiltration and/or cardiomyocyte disorganisation), and secondary eigenvector angle (E2A) (a marker of sheetlet orientation).LVRR was defined as EF within the normal indexed range, with evidence of prior severely reduced EF (