title: Development of a high-resolution fat and CSF-suppressed optic nerve DTI protocol at 3T: application in multiple sclerosis.
abstract: Clinical trials of neuroprotective interventions in multiple sclerosis require outcome measures that reflect the disease pathology. Measures of neuroaxonal integrity in the anterior visual pathways are of particular interest in this context, however imaging of the optic nerve is technically challenging. We therefore developed a 3T optic nerve diffusion tensor imaging protocol incorporating fat and cerebrospinal fluid suppression and without parallel imaging. The sequence used a scheme with six diffusion-weighted directions, b = 600 smm(-2) plus one b ≈ 0 (b(0)) and 40 repetitions, averaged offline, giving an overall scan time of 30 minutes. A coronal oblique orientation was used with voxel size 1.17 mm x 1.17 mm x 4 mm, We validated the sequence in 10 MS patients with a history of optic neuritis and 11 healthy controls: mean fractional anisotropy was reduced in the patients: 0.346(±0.159) versus 0.528(±0.123), p<0.001; radial diffusivity was increased: 0.940(±0.370)x10(-6) mm(2) s(-1) compared to 0.670(± 0.221)x10(-6) mm(2) s(-1) (p<0.01). No significant differences were seen for mean diffusivity or mean axial diffusivity.
authors.forename: R S
authors.initials: RS
authors.lastname: Samson
authors.forename: M
authors.initials: M
authors.lastname: Kolappan
authors.forename: D L
authors.initials: DL
authors.lastname: Thomas
authors.forename: M R
authors.initials: MR
authors.lastname: Symms
authors.forename: P
authors.initials: P
authors.lastname: Connick
authors.forename: D H
authors.initials: DH
authors.lastname: Miller
authors.forename: Claudia A M
authors.initials: CA
authors.lastname: Wheeler-Kingshott
mesh_terms: D000328:Adult; D016477:Artifacts; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000134:cerebrospinal fluid / Q000473:pathology*; D009900:Optic Nerve / Q000473:pathology*; D009902:Optic Neuritis / Q000473:pathology