Abstract for presentation at 38th Annual Scientific Meeting of the Australian and New Zealand Society of Nuclear Medicine 2008

Inflammation Imaging in Ischaemic Stroke using 11C-PK11195

  • Dr Graeme O'Keefe, Centre for P.E.T., Austin Health, Australia
  • Jorge Zavala, National Stroke Research Institute, Australia
  • Mr Timothy Saunder, Centre for P.E.T., Austin Health, Australia
  • Henri Tochon-Danguy, Centre for P.E.T., Austin Health, Australia
  • Gordon Chan, Centre for P.E.T., Austin Health, Australia
  • John Ly, National Stroke Research Institute, Australia
  • Prof Christopher Rowe, Centre for P.E.T., Austin Health, Australia
  • Geoffrey Donnan, National Stroke Research Institute, Australia

    • Objectives: Inflammation after an ischaemic insult to brain tissue may have a key role in the survival of viable hypo-perfused tissue. Microglial cells are activated within hours after an insult to the CNS. Marcophages accumulate after a period of days. Peropheral benzodiazepine binding sites (PBBS) are mitochondrial membrane receptors in microglia and macrophages. The ligand (R)-PK11195 binds to PBBS, and can be labelled with 11C to be used to image inflammatory response. The objectives of this study were to establish quantitative and statistical imaging methodologies for 11C-PK11195.

    Methods: 14 patients (68+/-9 yrs) and 7 controls (73+/-9.5 yrs) were injected with 11C-PK11195 (mean dose 550 MBq) and scanned dynamically on a Philips Allegro PET camera from injection for a period of 60 minutes (2-20 days post-stroke). The cerebellum was used as a reference region for the determination of distribution volumes (Vd) using the Logan analysis technique. A two-sample t-test was performed comparing individual patients and controls using SPM and the parametric Vd images. An uncorrected p-value threshold of 0.005 was applied when assessing patterns of change.

    Results: Six patients with cortical stroke images more than 3 days post stroke showed significant uptake confined to the stroke region. Three cortical stroke patients imaged less than 3 days post stroke and 4 lacunar stroke patients showed no significant uptake.

    Conclusions: SPM analysis of 11C-PK11195 distribution volume images has been used in the analysis of neuro-inflammation in stroke and demonstrates different patterns of inflammation based stroke etiology.

    Conference Organiser - ICMS Pty Ltd