title: Longitudinal gray matter changes in multiple sclerosis--differential scanner and overall disease-related effects.
abstract: Voxel-based morphometry (VBM) has been used repeatedly in single-center studies to investigate regional gray matter (GM) atrophy in multiple sclerosis (MS). In multi-center trials, across-scanner variations might interfere with the detection of disease-specific structural abnormalities, thereby potentially limiting the use of VBM. Here we evaluated longitudinally inter-site differences and inter-site comparability of regional GM in MS using VBM. Baseline and follow up 3D T1-weighted magnetic resonance imaging (MRI) data of 248 relapsing-remitting (RR) MS patients, recruited in two clinical centers, (center1/2: n = 129/119; mean age 42.6 ± 10.7/43.3 ± 9.3; male:female 33:96/44:75; median disease duration 150 [72-222]/116 [60-156]) were acquired on two different 1.5T MR scanners. GM volume changes between baseline and year 2 while controlling for age, gender, disease duration, and global GM volume were analyzed. The main effect of time on regional GM volume was larger in data of center two as compared to center one in most of the brain regions. Differential effects of GM volume reductions occurred in a number of GM regions of both hemispheres, in particular in the fronto-temporal and limbic cortex (cluster P corrected <0.05). Overall disease-related effects were found bilaterally in the cerebellum, uncus, inferior orbital gyrus, paracentral lobule, precuneus, inferior parietal lobule, and medial frontal gyrus (cluster P corrected <0.05). The differential effects were smaller as compared to the overall effects in these regions. These results suggest that the effects of different scanners on longitudinal GM volume differences were rather small and thus allow pooling of MR data and subsequent combined image analysis.
authors.affiliation: Medical Image Analysis Center, University Hospital Basel, CH-4031 Basel, Switzerland.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Bendfeldt
authors.forename: Louis
authors.initials: L
authors.lastname: Hofstetter
authors.forename: Pascal
authors.initials: P
authors.lastname: Kuster
authors.forename: Stefan
authors.initials: S
authors.lastname: Traud
authors.forename: Nicole
authors.initials: N
authors.lastname: Mueller-Lenke
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Naegelin
authors.forename: Ludwig
authors.initials: L
authors.lastname: Kappos
authors.forename: Achim
authors.initials: A
authors.lastname: Gass
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Nichols
authors.forename: Frederik
authors.initials: F
authors.lastname: Barkhof
authors.forename: Hugo
authors.initials: H
authors.lastname: Vrenken
authors.forename: Stefan D
authors.initials: SD
authors.lastname: Roosendaal
authors.forename: Jeroen J G
authors.initials: JJ
authors.lastname: Geurts
authors.forename: Ernst-Wilhelm
authors.initials: EW
authors.lastname: Radue
authors.forename: Stefan J
authors.initials: SJ
authors.lastname: Borgwardt
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002540:Cerebral Cortex / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000473:pathology* / Q000503:physiopathology; D013997:Time Factors