title: Inflamed human carotid plaques evaluated by PET/CT exhibit increased temperature: insights from an in vivo study.
abstract: OBJECTIVE
  To explore the relationship between temperature measurements derived by microwave radiometry (MWR) and carotid flurodeoxyglucose (FDG) uptake and assess their association with histological and immunohistochemistry findings in patients with high-grade carotid stenosis.
  
  
  RESULTS
  In 21 patients undergoing carotid endarterectomy, carotid inflammation was evaluated by both FDG positron emission/computed tomography (FDG-PET/CT) imaging and MWR measurements. Carotid inflammation was assessed by PET/CT as target-to-background ratio (TBR) by obtaining measurements in consecutive axial slices 2 cm below to 2 cm above the carotid bifurcation. Temperature difference (ΔT) by MWR was assigned as the maximum-minimum temperature measurements over the corresponding carotid segments. The extent of lipid core, calcification as well as CD68 and CD31 levels were also assessed. There was a significant correlation between ΔT values and FDG uptake (R = 0.40, P = 0.01), but no correlation between the degree of angiographic stenosis and ΔT values (R = -0.02, P = 0.91) or PET/CT measurements (R = -0.28, P = 0.86). Patients with plaques containing high lipid core extension or low calcification exhibited higher ΔT (P = 0.001 and P < 0.001, respectively) and FDG uptake values (P = 0.02 and P = 0.02, respectively). Patients with plaques containing increased CD68 expression exhibited higher ΔT and FDG uptake measurements.
  
  
  CONCLUSIONS
  Carotid plaque inflammation was evaluated by temperature measurements, which were correlated with FDG-PET/CT indices, confirmed by histopathology and immunohistochemistry findings. Structural changes did not predict inflammatory process. The implications of these findings in risk stratification and management of patients with carotid atherosclerosis and the precise algorithm for potential clinical utilization of MWR and PET/CT remain to be determined.
authors.affiliation: First Department of Cardiology, Hippokration Hospital, 114 Vassilisis Sofias St., 11527, Athens, Greece.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Toutouzas
authors.affiliation: First Department of Cardiology, Hippokration Hospital, 114 Vassilisis Sofias St., 11527, Athens, Greece.
authors.forename: Iosif
authors.initials: I
authors.lastname: Koutagiar
authors.affiliation: First Department of Cardiology, Hippokration Hospital, 114 Vassilisis Sofias St., 11527, Athens, Greece.
authors.forename: Georgios
authors.initials: G
authors.lastname: Benetos
authors.affiliation: First Department of Cardiology, Hippokration Hospital, 114 Vassilisis Sofias St., 11527, Athens, Greece.
authors.forename: Constantina
authors.initials: C
authors.lastname: Aggeli
authors.affiliation: Experimental Surgery, Clinical and Translational Research Centre, Biomedical Research Foundation, Academy of Athens, Soranou Ephesiou St., 11527, Athens, Greece.
authors.forename: Alexandros
authors.initials: A
authors.lastname: Georgakopoulos
authors.affiliation: Center of Systems Biology, Biomedical Research Foundation of the Academy of Athens 4 Soranou Ephesiou St., 11527.
authors.forename: Emmanouil
authors.initials: E
authors.lastname: Athanasiadis
authors.affiliation: Experimental Surgery, Clinical and Translational Research Centre, Biomedical Research Foundation, Academy of Athens, Soranou Ephesiou St., 11527, Athens, Greece.
authors.forename: Nikoletta
authors.initials: N
authors.lastname: Pianou
authors.affiliation: Department of Vascular Surgery, General Hospital 'Korgialenio-Benakio National Red Cross', Athens, Greece.
authors.forename: Sofoklis
authors.initials: S
authors.lastname: Trachanellis
authors.affiliation: Department of Propedeutic Surgery, Laiko Hospital, University of Athens, Athens, 17 Saint Thomas St., 11527, Greece.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Patelis
authors.affiliation: Department of Pathology, Athens Medical School, 75 Mikras Asias ST., 11527, Athens, Greece.
authors.forename: George
authors.initials: G
authors.lastname: Agrogiannis
authors.affiliation: Center of Systems Biology, Biomedical Research Foundation of the Academy of Athens 4 Soranou Ephesiou St., 11527.
authors.forename: Pavlos
authors.initials: P
authors.lastname: Kafouris
authors.affiliation: First Department of Cardiology, Hippokration Hospital, 114 Vassilisis Sofias St., 11527, Athens, Greece.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Filis
authors.affiliation: Department of Vascular Surgery, General Hospital 'Korgialenio-Benakio National Red Cross', Athens, Greece.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Bessias
authors.affiliation: Department of Propedeutic Surgery, Laiko Hospital, University of Athens, Athens, 17 Saint Thomas St., 11527, Greece.
authors.forename: Christos
authors.initials: C
authors.lastname: Klonaris
authors.affiliation: Center of Systems Biology, Biomedical Research Foundation of the Academy of Athens 4 Soranou Ephesiou St., 11527.
authors.forename: George
authors.initials: G
authors.lastname: Spyrou
authors.affiliation: First Department of Cardiology, Hippokration Hospital, 114 Vassilisis Sofias St., 11527, Athens, Greece.
authors.forename: Eleftherios
authors.initials: E
authors.lastname: Tsiamis
authors.affiliation: Centre for Materials Research & Innovation, University of Bolton, Deane Road, BL3 5AB, Bolton, UK.
authors.forename: Elias
authors.initials: E
authors.lastname: Siores
authors.affiliation: Department of Pathology, Athens Medical School, 75 Mikras Asias ST., 11527, Athens, Greece.
authors.forename: Efstratios
authors.initials: E
authors.lastname: Patsouris
authors.affiliation: Experimental Surgery, Clinical and Translational Research Centre, Biomedical Research Foundation, Academy of Athens, Soranou Ephesiou St., 11527, Athens, Greece.
authors.forename: Dennis
authors.initials: D
authors.lastname: Cokkinos
authors.affiliation: First Department of Cardiology, Hippokration Hospital, 114 Vassilisis Sofias St., 11527, Athens, Greece.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Tousoulis
authors.affiliation: Experimental Surgery, Clinical and Translational Research Centre, Biomedical Research Foundation, Academy of Athens, Soranou Ephesiou St., 11527, Athens, Greece.
authors.forename: Constantinos D
authors.initials: CD
authors.lastname: Anagnostopoulos
mesh_terms: D000368:Aged; D015703:Antigens, CD / Q000032:analysis; D015214:Antigens, Differentiation, Myelomonocytic / Q000032:analysis; D015415:Biomarkers / Q000032:analysis; D001831:Body Temperature; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008872:Microwaves; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging* / Q000473:pathology; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000032:analysis; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D061205:Vascular Calcification / Q000000981:diagnostic imaging / Q000473:pathology; D000097382:CD68 Molecule
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D015415:Biomarkers; D019788:Fluorodeoxyglucose F18; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D019275:Radiopharmaceuticals; C067980:CD68 antigen, human; D000097382:CD68 Molecule
keywords: 18F-FDG positron emission tomography; carotid atherosclerosis; inflammation; microwave radiometry