Alternative Diffusion Anisotropy Metric from Reduced MRI Acquisitions

A novel diffusion anisotropy metric is presented. It is based on dissimilarity between the acquired diffusion signal and its isotropic equivalent. Using the inner product of signals, a closed form expression is obtained, which allows its computation using spherical harmonics from a reduced set of acquired data, compatible with most popular diffusion MRI acquisition protocols. Results show that the proposed metric (1) is able to discriminate among different microstructure scenarios; (2) shows a robust behaviour in clinical studies.