Mezer's Lab: Tractography optimization using quantitative T1 mapping in the human optic radiation

Almost half of the human brain consists of “white matter” – bundles of fibers that connect distant brain regions. To study the white matter in the living human brain, researchers often use a method called diffusion MRI tractography. Recently, a specific white matter tract called the vertical occipital fasciculus (VOF) has attracted the attention of the neuroscientific community. The VOF is intriguing because it serves as the missing link between two separate visual systems in the brain. Accurate identification of the VOF is therefore of interest to studying human vision. We used method called T1 mapping and found that the VOF and the adjacent fibers have distinct microstructural signatures. This allowed us to automatically separate the VOF from its environment, and create a more informative model of its structure. Our results show that multi-modal MRI information, which characterizes tissue microstructure, can be used to delineate white matter tracts in vivo. This work signifies one more step towards a multi-modal atlas of human white matter.