Diffusion Tensor CMR in Assessing Biventricular Myocardial Fiber Orientation: A Comparative Study with Histology in a Miniature-Swine Model

Motivation: Diffusion tensor cardiac magnetic resonance (DT-CMR) has shown potential for non-invasive characterization of myocardial fiber orientation. Goal(s): The purpose of this study is to validate the accuracy of high-resolution DT-CMR in evaluating the arrangement of biventricular myocardial fibers in a miniature-swine model, using histological findings as the reference standard. Approach: High-resolution ex-vivo DT-CMR data of one healthy miniature-swine were acquired by a 3.0 T MRI system. Helix angles (HAs) in each segment from DT-CMR was compared with that from histology. Results: HAs evaluated by DT-CMR were closely correlated with those derived from histology (r = 0.958, P < 0.001) in 64 myocardial segments. Impact: Using histological validation in a miniature-swine model, high-resolution DT-CMR demonstrated good performance in non-invasively evaluating the arrangement of biventricular myocardial fibers. It provides histological evidence for DT-CMR to add more diagnostic and prognostic information in human cardiovascular diseases.