Microstructure-Informed Susceptibility Source Separation (MI-SSS) for Improved Estimation of Neural Myelin and Iron Content

Motivation: Current approaches to identify diamagnetic and paramagnetic susceptibility sources in the brain suffer from confounding effects caused by microstructure or pathological changes such as edema. Goal(s): The aim of this study is to present the microstructure-informed framework developed for the improved estimation of diamagnetic and paramagnetic sources free from confounding effects of fiber orientations and edema. Approach: We employ the biophysical modeling-based generation of gradient-echo signals and stochastic matching pursuit for the parameter estimation via a pre-computed dictionary. Results: The results show that MI-SSS is robust against the fiber orientation dependent field effects and increased tissue water. Impact: This study introduces MI-SSS as an improved susceptibility source separation technique. The aim is to map diamagnetic and paramagnetic source distributions inside the brain free from the confounding effects of fiber orientation and water content changes such as in edema.