Multi-echo gradient echo MRI of the lumbosacral spinal cord reveals level-dependent decreases in cross-sectional area in multiple sclerosis

Motivation: Understanding biological variability in the lumbosacral spinal cord is necessary for studying disease pathophysiology in persons with multiple sclerosis (pwMS). Goal(s): Determine which variables influence lumbosacral enlargement cross-sectional area and compare controls to pwMS. Approach: Multi-echo gradient echo images were acquired in 48 controls and 42 pwMS. The cord and gray matter were automatically segmented. Effects of biological variables and MS on cross-sectional areas were analyzed with linear mixed-effects models. Results: There were no significant main effects of age, sex, height or weight on MRI-derived cord and gray matter areas in controls. Spinal level-dependent decreases in cross-sectional areas were detected in pwMS. Impact: Characterizing contributions of biological variables to lumbosacral spinal cord MRI morphometry in healthy controls enables detection of disease-related effects such as cord and gray matter atrophy in pwMS, informing future studies of imaging biomarkers in the lumbosacral enlargement.