Diffusely abnormal white matter in progressive multiple sclerosis: in vivo quantitative MR imaging characterization and comparison between disease types.
OBJECTIVE
Recent postmortem studies in MS brain suggest that the severity of changes in DAWM can be measured by using quantitative MR imaging. This study aimed to characterize DAWM in vivo by using 4 quantitative MR imaging measures and to explore differences between MS disease types.


METHODS
In 17 patients with chronic MS (7 PP, 10 SP), quantitative MR imaging was performed at 1.5T, yielding whole-brain voxelwise maps of T1, MTR, ADC, and FA. ROIs were placed to obtain values for DAWM, NAWM, and WM lesions. A general linear mixed-model analysis was used to compare T1, MTR, ADC, and FA between tissue types and disease types.


RESULTS
Values of T1, MTR, ADC, and FA for DAWM were intermediate to those observed in NAWM and WM lesions. In patients with SPMS, DAWM was significantly different from both WM lesions and NAWM regarding all 4 measures, while in patients with PPMS, DAWM differed significantly from NAWM regarding T1, MTR, and FA and from lesions only regarding FA. Most interesting, DAWM differed between disease types: DAWM in patients with SPMS exhibited significantly higher T1 and lower MTR than did DAWM in patients with PPMS.


CONCLUSIONS
In vivo T1, MTR, ADC, and FA reflect the variable severity of pathologic changes in DAWM in MS. Moreover, these quantitative MR imaging measures suggest that DAWM may differ between PPMS and SPMS.
Vrenken
H
H
Department of Radiology, MS Center Amsterdam, VU University Medical Center, Amsterdam, The Netherlands. H.Vrenken@vumc.nl
Seewann
A
A
Knol
D L
DL
Polman
C H
CH
Barkhof
F
F
Geurts
J J G
JJ
D000328:Adult; D001921:Brain / Q000473:pathology*; D001931:Brain Mapping; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020528:Multiple Sclerosis, Chronic Progressive / Q000145:classification / Q000473:pathology*; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D012189:Retrospective Studies