title: Diffusion tensor imaging in multiple sclerosis: a tool for monitoring changes in normal-appearing white matter.
abstract: Our objectives were to determine the reproducibility of diffusion tensor imaging (DTI) in volunteers and to evaluate the ability of the method to monitor longitudinal changes occurring in the normal-appearing white matter (NAWM) of patients with multiple sclerosis (MS). DTI was performed three-monthly for one year in seven MS patients: three relapsing-remitting (RRMS), three secondary progressive (SPMS) and one relapsing SP. They were selected with a limited cerebral lesion load. Seven age- and sex-matched controls also underwent monthly examinations for three months. Diffusivity and anisotropy were quantified over the segmented whole supratentorial white matter, with the indices of trace (Tr) and fractional anisotropy (FA). Results obtained in volunteers show the reproducibility of the method. Patients had higher trace and lower anisotropy than matched controls (P < 0.0001). Over the follow-up, both Tr and FA indicated a recovery after the acute phase in RRMS and a progressive shift towards abnormal values in SPMS. Although this result is not statistically significant, it suggests that DTI is sensitive to microscopic changes occurring in tissue of normal appearance in conventional images and could be useful for monitoring the course of the disease, even though it was unable to clearly distinguish between the various physiopathological processes involved.
authors.affiliation: Department of Biophysics and Multimodality Imaging, University Paul Sabatier, Toulouse-Rangueil, France.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Cassol
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Ranjeva
authors.forename: Danielle
authors.initials: D
authors.lastname: Ibarrola
authors.forename: Claude
authors.initials: C
authors.lastname: Mékies
authors.forename: Claude
authors.initials: C
authors.lastname: Manelfe
authors.forename: Michel
authors.initials: M
authors.lastname: Clanet
authors.forename: Isabelle
authors.initials: I
authors.lastname: Berry
mesh_terms: D000328:Adult; D016880:Anisotropy; D001921:Brain / Q000473:pathology*; D004058:Diffusion; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D020528:Multiple Sclerosis, Chronic Progressive / Q000473:pathology*; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000473:pathology*; D009412:Nerve Fibers / Q000473:pathology