Reproducibility of advanced MR measures across all 3 major scanner vendors in a longitudinal 5-site multiple sclerosis study

Motivation: Advanced brain and spinal cord MRI is being collected in the Canadian prospective cohort study to understand progression in multiple sclerosis (CanProCo). Reproducibility was investigated in healthy controls. Goal(s): Determine reproducibility of brain volumetrics, myelin water fraction, magnetisation transfer ratio, diffusion tensor imaging metrics and spinal cord area across sites. Approach: 52 healthy controls were scanned at year 0 and 1 at a 3T site (2 Siemens, 2 Philips, 1 GE). Reproducibility was assessed using intraclass correlation coefficients, Bland-Altman plots and coefficients of variation. Results: Variability in most MR metrics was similar between sites although values themselves differed for a few metrics. Impact: CanProCo is a Canada-wide study collecting advanced brain and spinal cord MRI. Reproducibility of healthy control data was assessed to enable interpretation of longitudinal multi-site multiple sclerosis data. Variability in most MR metrics over 1 year was similar between sites.