title: Correlation between arterial FDG uptake and biomarkers in peripheral artery disease.
abstract: OBJECTIVE
  A prospective, multicenter (18)fluorine-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET)/computed tomography (CT) imaging study was performed to estimate the correlations among arterial FDG uptake and atherosclerotic plaque biomarkers in patients with peripheral artery disease.
  
  
  BACKGROUND
  Inflammation within atherosclerotic plaques is associated with instability of the plaque and future cardiovascular events. Previous studies have shown that (18)F-FDG-PET/CT is able to quantify inflammation within carotid artery atherosclerotic plaques, but no studies to date have investigated this correlation in peripheral arteries with immunohistochemical confirmation.
  
  
  METHODS
  Thirty patients across 5 study sites underwent (18)F-FDG-PET/CT imaging before SilverHawk atherectomy (FoxHollow Technologies, Redwood City, California) for symptomatic common or superficial femoral arterial disease. Vascular FDG uptake (expressed as target-to-background ratio) was measured in the carotid arteries and aorta and femoral arteries, including the region of atherectomy. Immunohistochemistry was performed on the excised atherosclerotic plaque extracts, and cluster of differentiation 68 (CD68) level as a measure of macrophage content was determined. Correlations between target-to-background ratio of excised lesions, as well as entire arterial regions, and CD68 levels were determined. Imaging was performed during the 2 weeks before surgery in all cases.
  
  
  RESULTS
  Twenty-one patients had adequate-quality (18)F-FDG-PET/CT peripheral artery images, and 34 plaque specimens were obtained. No significant correlation between lesion target-to-background ratio and CD68 level was observed.
  
  
  CONCLUSIONS
  There were no significant correlations between CD68 level (as a measure of macrophage content) and FDG uptake in the peripheral arteries in this multicenter study. Differences in lesion extraction technique, lesion size, the degree of inflammation, and imaging coregistration techniques may have been responsible for the failure to observe the strong correlations with vascular FDG uptake observed in previous studies of the carotid artery and in several animal models of atherosclerosis.
authors.affiliation: Translational and Molecular Imaging Institute, Mount Sinai School of Medicine, New York, New York 10029, USA.
authors.forename: Kelly S
authors.initials: KS
authors.lastname: Myers
authors.forename: James H F
authors.initials: JH
authors.lastname: Rudd
authors.forename: Eric P
authors.initials: EP
authors.lastname: Hailman
authors.forename: James A
authors.initials: JA
authors.lastname: Bolognese
authors.forename: Joanne
authors.initials: J
authors.lastname: Burke
authors.forename: Cathy Anne
authors.initials: CA
authors.lastname: Pinto
authors.forename: Michael
authors.initials: M
authors.lastname: Klimas
authors.forename: Richard
authors.initials: R
authors.lastname: Hargreaves
authors.forename: Hayes M
authors.initials: HM
authors.lastname: Dansky
authors.forename: Zahi A
authors.initials: ZA
authors.lastname: Fayad
mesh_terms: D000368:Aged; D015703:Antigens, CD / Q000032:analysis*; D015214:Antigens, Differentiation, Myelomonocytic / Q000032:analysis*; D001011:Aorta / Q000000981:diagnostic imaging / Q000276:immunology; D001158:Arteries / Q000000981:diagnostic imaging* / Q000276:immunology*; D015415:Biomarkers / Q000032:analysis; D002339:Carotid Arteries / Q000000981:diagnostic imaging / Q000276:immunology; D005240:Feasibility Studies; D005260:Female; D005263:Femoral Artery / Q000000981:diagnostic imaging / Q000276:immunology; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D058729:Peripheral Arterial Disease / Q000000981:diagnostic imaging* / Q000276:immunology*; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed; D014481:United States; D000097382:CD68 Molecule
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D015415:Biomarkers; D019788:Fluorodeoxyglucose F18; D019275:Radiopharmaceuticals; C067980:CD68 antigen, human; D000097382:CD68 Molecule