In multiple sclerosis, standard radiological metrics (i.e. lesion load) correlate poorly with clinical outcomes. To overcome this limitation, we propose a novel method to evaluate T1 relaxometry abnormalities along thirty-seven major white matter pathways extracted from a tractography atlas, i.e. without needing a diffusion scan. Evaluating T1 z-scores along WM tracts strongly improved correlation with disability compared to lesion load. The strongest correlations were found for T1 abnormalities in normal-appearing white matter, especially in infratentorial tracts. These results suggest that diffuse pathological changes in normal-appearing WM measured along atlas-based tracts using T1 relaxometry could aid clinical evaluation of multiple sclerosis.