Normal-appearing grey and white matter T1 abnormality in early relapsing-remitting multiple sclerosis: A longitudinal study

Objective: To investigate the presence and evolution of T1 relaxation time abnormalities in normal-appearing white matter (NAWM) and grey matter (GM), early in the course of relapsing-remitting multiple sclerosis (MS). Methods: Twenty-three patients with early relapsing-remitting MS and 14 healthy controls were imaged six monthly for up to three years. Mean follow-up was 26 months for MS patients and 24 months for controls. Dual-echo fast-spin echo and gradient-echo proton-density and T1-weighted data sets (permitting the calculation of a T1 map) were acquired in all subjects. GM and NAWM T1 histograms were produced and a hierarchical regression model was used to investigate changes in T1 over time. Results: At baseline, significant patient-control differences were seen, both in NAWM (P