RT Journal Article
SR Electronic
T1 Diffusion Tensor Tractography-Based Group Mapping of the Pyramidal Tract in Relapsing-Remitting Multiple Sclerosis Patients
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
SP 278
OP 282
VO 28
IS 2
A1 Lin, F.
A1 Yu, C.
A1 Jiang, T.
A1 Li, K.
A1 Chan, P.
YR 2007
UL http://www.ajnr.org/content/28/2/278.abstract
AB BACKGROUND AND PURPOSE: Many studies have reported abnormal changes in relapsing-remitting multiple sclerosis (RRMS) by histogram and region-of-interest–based methods by using diffusion tenor imaging. However, there are few studies on specific white matter fiber tracts of RRMS. Our study sought to use diffusion tensor tractography–based group mapping to investigate the presence of abnormal diffusion in the normal-appearing pyramidal tract (PYT) of RRMS and its possible mechanism.METHODS: A PYT probability map was first constructed from data on 20 healthy patients based on the deterministic-based tractography method. The PYT probability map was then applied to 29 RRMS patients to calculate diffusion indices of the PYT. In this study, 4 quantitative indices—fractional anisotropy (FA), directionally averaged diffusion coefficient (Dav), axial diffusion coefficient (λ1), and radial diffusion coefficient (λ23)—were used to characterize the abnormal diffusion.RESULTS: Compared with healthy controls, RRMS patients had a significantly higher Dav and λ23 but a lower FA and a trend toward a lower λ1 in the normal-appearing PYT. In RRMS patients, PYT lesions had a significantly higher λ23 and a lower FA, but there were no differences for Dav and λ1 when compared with the normal-appearing PYT. Moreover, the diffusion indices derived from the normal-appearing PYT were significantly correlated with PYT lesion volumes by using the Spearman correlation analysis.CONCLUSION: Our findings confirm the presence of abnormal diffusion in the normal-appearing PYT of RRMS patients and suggest that wallerian degeneration might be its mechanism.