1) To develop an improved pipeline that standardizes T1-w/T2-w images or "myelin maps (MM)".

2) To validate this pipeline in patients with classic trigeminal neuralgia (CTN) and trigeminal neuralgia secondary to multiple sclerosis (MSTN). 

T1-w and T2-w images were obtained for 17 CTN and 17 MSTN patients. Multiple sclerosis (MS) plaques and normal-appearing white matter (NAWM) were labelled in MSTN patients. Template images, gray matter (GM) masks, and white matter (WM) masks were acquired from the ICBM152 database. For each patient image, a Gaussian curve-fit was applied to the histogram of the intensity distribution and transformed to match the Gaussian curve-fit of its template image. Gaussian curve-fits were also performed to obtain the mean intensities of GM, WM, MS plaques, and NAWM.

Reduced variability in GM and WM histogram peaks among patients permits meaningful inter-subject comparisons. MM analysis revealed reduced myelin content in MS plaques compared to corresponding regions in CTN patients and surrounding NAWM in MSTN patients. The standardized MM serves as a non-invasive tool for quantitative analyses of myelin content between different brain regions and different patients in vivo.