Backscattering Mueller Matrix polarimetry shows promise for validation of diffusion MRI microstructural features in thick tissue specimens

Abstract

Ground truth validation methods are essential to improve the accuracy of biophysical representation by diffusion MRI methods. The objective of this study is to advance PLI methodology for thick tissue imaging of fiber distributions by application of multispectral backscattering polarimetry, and of the Mueller matrix mathematical framework for unmixing contributions from depolarization, diattenutation, and retardance. Our results indicate that orientation features derived from PLI are in concordance with known brain physiology. Due to the consistent presence of retardance even in areas of crossing fibers, the results suggest that retardance angle is most sensitive to microstructural features rather than macroscopic geometry.