Microglial imaging with positron emission tomography and atrophy measurements with magnetic resonance imaging in multiple sclerosis: a correlative study.
OBJECTIVE
The objectives of the present study were to assess brain atrophy in multiple sclerosis (MS) patients during different disease stages and to investigate by PET and [11C]PK11195, a marker of microglial activation, the relationship between inflammation, atrophy and clinically relevant measures.


METHODS
Eight healthy subjects and 22 MS patients were included. Semiquantitative [11C]PK11195 uptake values, with normalization on cortical grey matter, were measured for magnetic resonance imaging T2- and T1-lesions and normal appearing white matter (NAWM). As atrophy index we used the ratio of the amount of white and grey matter divided by the ventricular size, using an optimized a priori based segmentation algorithm (SPM99).


RESULTS
Atrophy was significantly greater in MS patients compared to age-matched controls. A significant correlation was found between brain atrophy and both disease duration and disability, as measured with the Expanded Disability Status Scale. For NAWM, [11C]PK11195 uptake increased with the amount of atrophy, while T2-lesional [11C]PK11195 uptake values decreased according to increasing brain atrophy.


CONCLUSIONS
The present study suggests that brain atrophy, correlating with disease duration and disability, is directly related to NAWM and T2-lesional inflammation as measured by microglial activation.
Versijpt
J
J
Ghent University Hospital, Ghent, the Netherlands.
Debruyne
J C
JC
Van Laere
K J
KJ
De Vos
F
F
Keppens
J
J
Strijckmans
K
K
Achten
E
E
Slegers
G
G
Dierckx
R A
RA
Korf
J
J
De Reuck
J L
JL
D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000493:pharmacokinetics; D001284:Atrophy; D001921:Brain / Q000473:pathology*; D002250:Carbon Radioisotopes; D005260:Female; D006801:Humans; D007546:Isoquinolines / Q000493:pharmacokinetics; D008279:Magnetic Resonance Imaging; D008297:Male; D017628:Microglia / Q000473:pathology*; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000473:pathology*; D049268:Positron-Emission Tomography / Q000379:methods*
D000970:Antineoplastic Agents; D002250:Carbon Radioisotopes; D007546:Isoquinolines; C037850:PK 11195