title: Delayed ¹⁸F-fluorodeoxyglucose PET/CT imaging improves quantitation of atherosclerotic plaque inflammation: results from the CAMONA study.
abstract: BACKGROUND
  This study aimed to determine if delayed (18)F-fluorodeoxyglucose ((18)FDG) PET/CT imaging improves quantitation of atherosclerotic plaque inflammation. Blood-pool activity can disturb the arterial (18)FDG signal. With time, blood-pool activity declines. Therefore, delayed imaging can potentially improve quantitation of vascular inflammation.
  
  
  RESULTS
  40 subjects were prospectively assessed by dual-time-point PET/CT imaging at approximately 90 and 180 minutes after (18)FDG administration. For both time-points, global uptake of (18)FDG was determined in the carotid arteries and thoracic aorta by calculating the blood-pool corrected maximum standardized uptake value (cSUVMAX). A target-to-background ratio (TBR) was calculated to determine the contrast resolution at 90 and 180 minutes. Furthermore, we assessed whether the acquisition time-point affected the relation between cSUVMAX and the estimated 10-year risk for fatal cardiovascular disease (SCORE %). A significant increase in carotid cSUVMAX (23%, P < .0001), carotid TBR (20%, P < .0001), aortic cSUVMAX (14%, P < .0001), and aortic TBR (20%, P < .0001) was observed with time. At 90 minutes, cSUVMAX did not relate to SCORE %, whereas at 180 minutes significant positive relations were observed between SCORE % and carotid (τ = 0.25, P = .045) and aortic (τ = 0.33, P = .008) cSUVMAX.
  
  
  CONCLUSIONS
  Delayed (18)FDG PET/CT imaging at 180 minutes improves quantitation of atherosclerotic plaque inflammation over imaging at 90 minutes. Therefore, the optimal acquisition time-point to assess atherosclerotic plaque inflammation lies beyond the advocated time-point of 90 minutes after (18)FDG administration.
authors.affiliation: Department of Nuclear Medicine, Odense University Hospital, Sdr. Boulevard 29, 5000, Odense, Denmark, b.a.blomberg@umcutrecht.nl.
authors.forename: Björn A
authors.initials: BA
authors.lastname: Blomberg
authors.forename: Anders
authors.initials: A
authors.lastname: Thomassen
authors.forename: Richard A P
authors.initials: RA
authors.lastname: Takx
authors.forename: Malene G
authors.initials: MG
authors.lastname: Hildebrandt
authors.forename: Jane A
authors.initials: JA
authors.lastname: Simonsen
authors.forename: Karen M
authors.initials: KM
authors.lastname: Buch-Olsen
authors.forename: Axel C P
authors.initials: AC
authors.lastname: Diederichsen
authors.forename: Hans
authors.initials: H
authors.lastname: Mickley
authors.forename: Abass
authors.initials: A
authors.lastname: Alavi
authors.forename: Poul F
authors.initials: PF
authors.lastname: Høilund-Carlsen
mesh_terms: D000328:Adult; D000465:Algorithms; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000008:administration & dosage*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000008:administration & dosage; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18