title: Carotid plaque inflammation assessed with (18)F-FDG PET/CT is higher in symptomatic compared with asymptomatic patients.
abstract: BACKGROUND
  Carotid artery plaque inflammation is thought to be an important marker of plaque vulnerability and increased stroke risk.
  
  
  OBJECTIVE
  The main aim of this study was to assess the level of agreement between 2-deoxy-2-[(18)F] fluoro-D-glucose (18F-FDG) uptake on PET (positron emission tomography) scan in carotid plaques, with cerebrovascular symptoms, carotid plaque ultrasound echogenicity and histological assessments of plaque inflammation.
  
  
  METHODS
  Thirty-six patients with ≥70% carotid stenosis scheduled for carotid endarterectomy underwent a Colour Duplex ultrasound, (18)F-FDG PET/CT and blood tests less than 24 h prior to surgery. Plaques were defined as symptomatic when associated with ipsilateral cerebral ischemic symptoms within 30 days prior to inclusion. Plaques were assessed histologically following endarterectomy. The level of agreement between (18)F-FDG uptake (mean SUVmax and SUVmax ), and target-to-background ratio, symptoms, plaque echolucency, and histological evidence of inflammation was assessed.
  
  
  RESULTS
  The amount of (18)F-FDG uptake in plaques and the amount of inflammation on histological assessment were significantly correlated (r = 0·521, P = 0·003). (18)F-FDG uptake was significantly higher in symptomatic plaques with median SUVmax 1·75 (1·26-2·04) in symptomatic, and 1·43 (1·15-2·28) in asymptomatic patients (P = 0·03). (18)F-FDG uptake was also positively correlated with echolucency on Doppler ultrasound (P = 0·03).
  
  
  CONCLUSIONS
  (18)F-FDG uptake on PET/CT correlated with histological assessments of inflammation and was higher in patients with symptomatic compared with asymptomatic carotid artery plaques. These results support the use of (18)F-FDG PET/CT in the detection inflammation in carotid atherosclerosis, which may be of help in the detection of vulnerable plaques.
authors.affiliation: Department of Neurology, Oslo University Hospital and University of Oslo, Oslo, Norway.
authors.forename: Karolina
authors.initials: K
authors.lastname: Skagen
authors.affiliation: Department of Radiology and Nuclear Medicine, Oslo University Hospital and University of Oslo, Oslo, Norway.
authors.forename: Kjersti
authors.initials: K
authors.lastname: Johnsrud
authors.affiliation: Department of Neurology, Oslo University Hospital and University of Oslo, Oslo, Norway.
authors.forename: Kristin
authors.initials: K
authors.lastname: Evensen
authors.affiliation: Department of Pathology, Oslo University Hospital and University of Oslo, Oslo, Norway.
authors.forename: Helge
authors.initials: H
authors.lastname: Scott
authors.affiliation: Department of Thoracic Surgery, Oslo University Hospital and University of Oslo, Oslo, Norway.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Krohg-Sørensen
authors.affiliation: Department of Vascular and Thoracic surgery, Akershus University Hospital, Oslo, Norway.
authors.forename: Frode
authors.initials: F
authors.lastname: Reier-Nilsen
authors.affiliation: Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway.
authors.forename: Mona-Elisabeth
authors.initials: ME
authors.lastname: Revheim
authors.affiliation: Department of Radiology and Nuclear Medicine, Oslo University Hospital and Akershus University College of Applied Sciences, Oslo, Norway.
authors.forename: Jan Gunnar
authors.initials: JG
authors.lastname: Fjeld
authors.affiliation: Department of Neurology, Oslo University Hospital and University of Oslo, Oslo, Norway.
authors.forename: Mona
authors.initials: M
authors.lastname: Skjelland
authors.affiliation: Department of Neurology, Oslo University Hospital and University of Oslo, Oslo, Norway.
authors.forename: David
authors.initials: D
authors.lastname: Russell
mesh_terms: D000368:Aged; D016893:Carotid Stenosis / Q000000981:diagnostic imaging; D016894:Endarterectomy, Carotid; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007249:Inflammation / Q000150:complications / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination; D049268:Positron-Emission Tomography; D012189:Retrospective Studies; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed; D018615:Ultrasonography, Doppler, Color
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: carotid plaque; carotid plaque echogenicity; carotid stenosis; carotid ultrasound; ischemic stroke; positron emission tomography