MR Study of Myocardial Fiber Structure Using Diffusion Tensor Imaging

This paper discussed the left ventricular myocardium structure in both normal and pathological states using diffusion tensor imaging. Myocardial fiber pathway distribution was investigated in normal canine hearts, and effects of infarct size and location on myocardium structure remodeling were studied in LADand LCX-related myocardium infarct (MI) porcine models. Majority fiber pathways were found to have small helix angles and dominate the fiber architecture in normal myocardium. While in the two MI groups studied, substantial fiber quality degraded in infarct region with significant correlation with infarct size. The double-helical structure shifted towards more left-handed, especially in LAD-related MI group. The results suggest that both infarct size and location affect the myocardium structural remodeling. These studies not only provide supplemental information on myocardial fiber architecture and cardiac mechanics in normal hearts, but also revealed the alterations in myocardial fiber quality and structure in infarct hearts.