title: [18F]FDG Accumulation in Early Coronary Atherosclerotic Lesions in Pigs.
abstract: OBJECTIVE
  Inflammation is an important contributor to atherosclerosis progression. A glucose analogue 18F-fluorodeoxyglucose ([18F]FDG) has been used to detect atherosclerotic inflammation. However, it is not known to what extent [18F]FDG is taken up in different stages of atherosclerosis. We aimed to study the uptake of [18F]FDG to various stages of coronary plaques in a pig model.
  
  
  METHODS
  First, diabetes was caused by streptozotocin injections (50 mg/kg for 3 days) in farm pigs (n = 10). After 6 months on high-fat diet, pigs underwent dual-gated cardiac PET/CT to measure [18F]FDG uptake in coronary arteries. Coronary segments (n = 33) were harvested for ex vivo measurement of radioactivity and autoradiography (ARG).
  
  
  RESULTS
  Intimal thickening was observed in 16 segments and atheroma type plaques in 10 segments. Compared with the normal vessel wall, ARG showed 1.7±0.7 times higher [18F]FDG accumulation in the intimal thickening and 4.1±2.3 times higher in the atheromas (P = 0.004 and P = 0.003, respectively). Ex vivo mean vessel-to-blood ratio was higher in segments with atheroma than those without atherosclerosis (2.6±1.2 vs. 1.3±0.7, P = 0.04). In vivo PET imaging showed the highest target-to-background ratio (TBR) of 2.7. However, maximum TBR was not significantly different in segments without atherosclerosis (1.1±0.5) and either intimal thickening (1.2±0.4, P = 1.0) or atheroma (1.6±0.6, P = 0.4).
  
  
  CONCLUSIONS
  We found increased uptake of [18F]FDG in coronary atherosclerotic lesions in a pig model. However, uptake in these early stage lesions was not detectable with in vivo PET imaging. Further studies are needed to clarify whether visible [18F]FDG uptake in coronary arteries represents more advanced, highly inflamed plaques.
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
authors.forename: Miikka
authors.initials: M
authors.lastname: Tarkia
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland; Heart Center, Turku University Hospital and University of Turku, Turku, Finland; Institute of Clinical Medicine, University of Turku, Turku, Finland.
authors.forename: Antti
authors.initials: A
authors.lastname: Saraste
authors.affiliation: Research Centre of Applied and Preventive Cardiovascular Medicine, University of Turku, Turku, Finland; Heart Center, Turku University Hospital and University of Turku, Turku, Finland.
authors.forename: Christoffer
authors.initials: C
authors.lastname: Stark
authors.affiliation: Research Centre of Applied and Preventive Cardiovascular Medicine, University of Turku, Turku, Finland; Heart Center, Turku University Hospital and University of Turku, Turku, Finland.
authors.forename: Tommi
authors.initials: T
authors.lastname: Vähäsilta
authors.affiliation: Research Centre of Applied and Preventive Cardiovascular Medicine, University of Turku, Turku, Finland; Heart Center, Turku University Hospital and University of Turku, Turku, Finland.
authors.forename: Timo
authors.initials: T
authors.lastname: Savunen
authors.affiliation: Heart Center, Turku University Hospital and University of Turku, Turku, Finland.
authors.forename: Marjatta
authors.initials: M
authors.lastname: Strandberg
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
authors.forename: Virva
authors.initials: V
authors.lastname: Saunavaara
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
authors.forename: Tuula
authors.initials: T
authors.lastname: Tolvanen
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
authors.forename: Jarmo
authors.initials: J
authors.lastname: Teuho
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
authors.forename: Mika
authors.initials: M
authors.lastname: Teräs
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
authors.forename: Olli
authors.initials: O
authors.lastname: Metsälä
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
authors.forename: Petteri
authors.initials: P
authors.lastname: Rinne
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
authors.forename: Ilkka
authors.initials: I
authors.lastname: Heinonen
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
authors.forename: Nina
authors.initials: N
authors.lastname: Savisto
authors.affiliation: Heart Center, Turku University Hospital and University of Turku, Turku, Finland.
authors.forename: Mikko
authors.initials: M
authors.lastname: Pietilä
authors.affiliation: Department of Forensic Medicine, University of Turku, Turku, Finland.
authors.forename: Pekka
authors.initials: P
authors.lastname: Saukko
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
authors.forename: Anne
authors.initials: A
authors.lastname: Roivainen
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
authors.forename: Juhani
authors.initials: J
authors.lastname: Knuuti
mesh_terms: D000818:Animals; D050197:Atherosclerosis / Q000097:blood / Q000000981:diagnostic imaging*; D001345:Autoradiography; D001786:Blood Glucose / Q000378:metabolism; D002784:Cholesterol / Q000097:blood; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000473:pathology; D003920:Diabetes Mellitus / Q000000981:diagnostic imaging*; D005215:Fasting / Q000097:blood; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism*; D055806:Microvessels / Q000000981:diagnostic imaging / Q000473:pathology; D009206:Myocardium / Q000473:pathology; D049268:Positron-Emission Tomography; D034421:Sus scrofa; D014018:Tissue Distribution; D014057:Tomography, X-Ray Computed
chemical_list: D001786:Blood Glucose; D019788:Fluorodeoxyglucose F18; D002784:Cholesterol