Myelin Mapping in Living Mice Using Magnetization Transfer and Manganese

Takashi Watanabe¹, Jens Frahm¹, Thomas Michaelis¹

This work demonstrates for the first time the use of manganese for mapping myelin-rich structures in the brain of living mice in magnetization-transfer weighted MRI (3D FLASH). The contrast between myelin-rich structures and background was improved after manganese injection. A reduced saturation of mobile protons was pronouncedly seen in the water-rich background, while the marked saturation in myelin-rich structures through magnetization transfer from the large pool of bound protons was less affected. Administration of hydrophilic T1-shortening agents to neural tissue fluid in vivo increases the signal intensity of the brain advantageously for a magnetization-transfer based mapping of myelin-rich structures.