High-Resolution FLAIR DTI Tractography of the Fornix in Multiple Sclerosis

Diffusion tensor imaging (DTI) tractography of the human fornix is biased by partial volume effects from cerebrospinal fluid (CSF) due to its small bundle size and intra-ventricular location, even when using high spatial resolution. These errors in diffusion parameter estimation and tracking of the fornix will worsen with axonal loss in multiple sclerosis (MS). Here we demonstrate the superiority of FLAIR-DTI, even when compared to high-resolution 1.5 mm isotropic DTI, to mitigate CSF contamination of fornix tractography in MS and healthy volunteers. FLAIR-DTI yields more accurate diffusion metrics in both cohorts, and still shows abnormal fornix in MS.