Imaging of vascular inflammation with [11C]-PK11195 and positron emission tomography/computed tomography angiography

Francesca Pugliese, Oliver Gaemperli, Anne R. Kinderlerer, Frederic Lamare, Joseph Shalhoub, Alun Huw Davies, Ornella E. Rimoldi, Justin C. Mason, Paolo G. Camici

Research output: Contribution to journalArticlepeer-review


Objectives: We sought to investigate whether positron emission tomography/computed tomography (CT) angiography using [11C]-PK11195, a selective ligand for peripheral benzodiazepine receptors expressed in activated macrophages, can be used to image vascular inflammation. Background: Activated macrophages and T lymphocytes are fundamental elements in the pathogenesis of large-vessel vasculitides. Methods: Fifteen patients (age 52 ± 16 years) with systemic inflammatory disorders (6 consecutive symptomatic patients with clinical suspicion of active vasculitis and 9 asymptomatic control patients) underwent positron emission tomography with [11C]-PK11195 and CT angiography. [11C]-PK11195 uptake was measured by calculating target-to-background ratios of activity normalized to venous blood. Results: Coregistration of positron emission tomography with contrast-enhanced CT angiography facilitated localization of [ 11C]-PK11195 arterial wall uptake. Visual analysis revealed focal [11C]-PK11195 uptake in the arterial wall of all 6 symptomatic patients, but in none of the asymptomatic controls. Although serum inflammatory biomarkers (C-reactive protein, erythrocyte sedimentation rate, white cell count) did not differ significantly between the 2 groups, symptomatic patients had increased [11C]-PK11195 vascular uptake (target-to-background ratio 2.41 ± 1.59 vs. 0.98 ± 0.10; p = 0.001). Conclusions: By binding to activated macrophages in the vessel wall, [11C]-PK11195 enables noninvasive imaging of vascular inflammation. Alternative longer-lived radioligands for probing peripheral benzodiazepine receptors are being tested for wider clinical applications.

Original languageEnglish
Pages (from-to)653-661
Number of pages9
JournalJournal of the American College of Cardiology
Issue number8
Publication statusPublished - Aug 17 2010


  • C-reactive protein
  • computed tomography
  • CRP
  • CT
  • erythrocyte sedimentation rate
  • ESR
  • FDG
  • GCA
  • giant cell arteritis
  • high-performance liquid chromatography
  • HPLC
  • PBR
  • peripheral benzodiazepine receptor
  • PET
  • positron emission tomography
  • region of interest
  • ROI
  • SLE
  • standardized uptake value
  • SUV
  • systemic lupus erythematosus
  • TA
  • Takayasu's arteritis
  • target-to-background ratio
  • TBR

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Medicine(all)


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