Mapping Free Water in the Brain Using Multiparameter qMRI Combined with an Iterative Fast Exchange Relaxation Model

Purpose: To develop an integrated theoretical model and computer algorithms for mapping individually and simultaneously the spatial distributions of free water, alongside myelin and iron. Theory: We solve a fast exchange relaxation model effectively decomposing qMRI maps of nPD, R1, and R2 into maps of free water, myelin, and iron. Results: The image processing technique generates maps of free water, myelin, and iron in the brains of adolescents born extremely preterm. Conclusion: A theoretical framework and image processing pipeline for mapping the distribution of free water has been developed and tested with a cohort of adolescents born extremely preterm.