Ken E. Sakaie1, Jian Lin1, Lael Stone2, Mark J. Lowe1
1Imaging Institute, The Cleveland Clinic, Cleveland, OH, United States; 2Mellen Center, The Cleveland Clinic, Cleveland, OH, United States
Tissue microstructure measurements specific to a tractography-defined white matter fascicle may serve as a clinically relevant measure in multiple sclerosis (MS). One problem is substantial variability along a fascicle, particularly if it includes regions near cortex and deeper in the brain. We present a methodology for segmenting a fascicle identified by probabilistic tractography and demonstrate its use in the transcallosal motor pathway of healthy subjects and MS patients. Using this method, tissue microstructure measurements can be made in a piecewise manner in order to reduce the overall variance and improve sensitivity to local differences.