Microglial imaging with positron emission tomography and atrophy measurements with magnetic resonance imaging in multiple sclerosis: a correlative study

Mult Scler. 2005 Apr;11(2):127-34. doi: 10.1191/1352458505ms1140oa.


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.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Antineoplastic Agents / pharmacokinetics
  • Atrophy
  • Brain / pathology*
  • Carbon Radioisotopes
  • Female
  • Humans
  • Isoquinolines / pharmacokinetics
  • Magnetic Resonance Imaging*
  • Male
  • Microglia / pathology*
  • Middle Aged
  • Multiple Sclerosis / pathology*
  • Positron-Emission Tomography / methods*


  • Antineoplastic Agents
  • Carbon Radioisotopes
  • Isoquinolines
  • PK 11195