White matter T1 relaxation time histograms and cerebral atrophy in multiple sclerosis

T1 relaxation time (T1) provides a quantitative magnetic resonance imaging (MRI) parameter for evaluating tissue damage in the brain. We aimed to measure T1 in the white matter of patients with multiple sclerosis (MS) and study relationships with cerebral atrophy, T2 lesion load and clinical parameters. Twenty-six patients with relapsing–remitting MS and sixteen healthy controls were scanned with dual-echo T2-weighted, 3-dimensional (3-D) magnetization-prepared rapid acquisition gradient echo and whole brain, multi-slice inversion recovery (IR) sequences. White matter masks were defined on axial T1 map slices using semi-automated seed growing and normalized ‘total white matter’ T1 histograms generated. Atrophy data was obtained using the Cavalieri method of modern design stereology. T2 lesion volume was also determined using seed growing.