title: Microglial imaging with positron emission tomography and atrophy measurements with magnetic resonance imaging in multiple sclerosis: a correlative study.
abstract: 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.
authors.affiliation: Ghent University Hospital, Ghent, the Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Versijpt
authors.forename: J C
authors.initials: JC
authors.lastname: Debruyne
authors.forename: K J
authors.initials: KJ
authors.lastname: Van Laere
authors.forename: F
authors.initials: F
authors.lastname: De Vos
authors.forename: J
authors.initials: J
authors.lastname: Keppens
authors.forename: K
authors.initials: K
authors.lastname: Strijckmans
authors.forename: E
authors.initials: E
authors.lastname: Achten
authors.forename: G
authors.initials: G
authors.lastname: Slegers
authors.forename: R A
authors.initials: RA
authors.lastname: Dierckx
authors.forename: J
authors.initials: J
authors.lastname: Korf
authors.forename: J L
authors.initials: JL
authors.lastname: De Reuck
mesh_terms: 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*
chemical_list: D000970:Antineoplastic Agents; D002250:Carbon Radioisotopes; D007546:Isoquinolines; C037850:PK 11195