A new qMRI approach for mapping microscopic water populations and tissue relaxivity in the in-vivo human brain

We present an array of new quantitative maps, highlighting different aspects of the tissue’s water. Furthermore, our technique allows to calculate the voxel-wise tissue relaxivity, associated with the molecular composition of the brain. Our approach is based on the pioneering two-site exchange model. We implemented it for magnetization-transfer weighted water content mapping of brain tissue for the first time. The new in-vivo MRI measurements conform well with the theory. They can be easily acquired with the standard quantitative MRI protocol and do not require complex data fitting. Therefore, the proposed technique may further advance human brain research and diagnosis.