Biexponential diffusion tensor analysis of myocardial structural alteration in rabbit models with myocardium infarction

Abstract

Water diffusion behavior in some tissues was found to not comply with Gaussian manner, leading to diffusion strength dependence of DTI index characterization. In this study, infarcted myocardial structural alteration was investigated using biexponential model, which was proved to better fit of diffusion signal decay. DTI results showed that in both infarct and adjacent regions fast radial diffusivity increased due to extracellular and microvascular compartment augmentation along radial direction, leading to enhancement of fast mean diffusivity. Meanwhile, decrease of both fast and slow FA was observed as result of fiber integrity loss and fast radial diffusivity enhancement. These findings were validated by histological observations. The current study suggested that biexponential diffusion function could be utilized as a tool to monitor and detect myocardial morphological alteration and structural degradation by probing multi-compartment diffusion behavior compared to conventional used monoexponential diffusion model.