Fractional Anisotropy Derived from the Diffusion Tensor Distribution Function Boosts Power to Detect Alzheimer’s Disease Deficits

摘要

PurposeIn diffusion MRI (dMRI), fractional anisotropy derived from the single-tensor model (FA^DTI) is the most widely used metric to characterize white matter (WM) micro-architecture, despite known limitations in regions with crossing fibers. Due to time constraints when scanning patients in clinical settings, high angular resolution diffusion imaging (HARDI) acquisition protocols, often used to overcome these limitations, are still rare in clinical population studies. However, the tensor distribution function (TDF) may be used to model multiple underlying fibers by representing the diffusion profile as a probabilistic mixture of tensors.