title: Quantification of temporal changes in calcium score in active atherosclerotic plaque in major vessels by18F-sodium fluoride PET/CT.
abstract: OBJECTIVE
  Our aim was to assess whether18F-NaF PET/CT is able to predict progression of the CT calcium score.
  
  
  METHODS
  Between August 2007 and November 2015, 34 patients (18 women, 16 men; age, mean ± standard deviation, 57.5 ± 13.9 years; age range 19-78 years) with malignancy or orthopaedic disease were enrolled in this study, with approximately 1-year follow-up data. Baseline and follow-up CT images were retrospectively evaluated for the presence of calcification sites in major vessel walls. The maximum and mean CT values (CTmax and CTmean, in Hounsfield units), calcification volumetric score (CVS, in cubic millimetres) and Agatston units score (AU) were evaluated for each site. Subsequent changes in CTmax, CTmean, CVS and AU were calculated and expressed as ΔCTmax, ΔCTmean, ΔCVS and ΔAU, respectively. We then evaluated the relationship between18F-NaF uptake (using the maximum target-to-background ratio, TBRmax, and the maximum blood-subtracted18F-NaF activity, bsNaFmax, which was obtained by subtracting the SUVmax of each calcified plaque lesion and NaF-avid site from the SUVmean in the right atrium blood pool) and the change in calcified plaque volume and characteristics obtained after 1 year.
  
  
  RESULTS
  We detected and analysed 182 calcified plaque sites and 96 hot spots on major vessel walls.18F-NaF uptake showed very weak correlations with CTmax, CTmean, CVS, CVS after 1 year, AU and AU after 1 year on both baseline and follow-up PET/CT scans for each site.18F-NaF uptake showed no correlation with ΔCTmax or ΔCTmean. However, there was a significant correlation between the intensity of18F-NaF uptake and ΔCVS and ΔAU.
  
  
  CONCLUSIONS
  18F-NaF uptake has a strong correlation with calcium score progression which was a predictor of future cardiovascular disease risk. PET/CT using18F-NaF may be able to predict calcium score progression which is known to be the major characteristic of atherosclerosis.
authors.affiliation: Department of Radiology, Yokohama City University, Graduate School of Medicine, 3-9, Fukuura, Kanazawa-ward, Yokohama, Kanagawa, 236-0004, Japan.
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Ishiwata
authors.affiliation: Department of Radiology, Yokohama City University, Graduate School of Medicine, 3-9, Fukuura, Kanazawa-ward, Yokohama, Kanagawa, 236-0004, Japan. kaneta@yokohama-cu.ac.jp.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Kaneta
authors.affiliation: Department of Radiology, Yokohama City University, Graduate School of Medicine, 3-9, Fukuura, Kanazawa-ward, Yokohama, Kanagawa, 236-0004, Japan.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Nawata
authors.affiliation: Department of Radiology, Yokohama City University, Graduate School of Medicine, 3-9, Fukuura, Kanazawa-ward, Yokohama, Kanagawa, 236-0004, Japan.
authors.forename: Ayako
authors.initials: A
authors.lastname: Hino-Shishikura
authors.affiliation: Department of Radiology, Yokohama City University, Graduate School of Medicine, 3-9, Fukuura, Kanazawa-ward, Yokohama, Kanagawa, 236-0004, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Yoshida
authors.affiliation: Department of Radiology, Yokohama City University, Graduate School of Medicine, 3-9, Fukuura, Kanazawa-ward, Yokohama, Kanagawa, 236-0004, Japan.
authors.forename: Tomio
authors.initials: T
authors.lastname: Inoue
mesh_terms: D000328:Adult; D000368:Aged; D002118:Calcium / Q000378:metabolism*; D005260:Female; D005462:Fluorine Radioisotopes; D006801:Humans; D008297:Male; D008875:Middle Aged; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging* / Q000378:metabolism*; D000072078:Positron Emission Tomography Computed Tomography; D015203:Reproducibility of Results; D012969:Sodium Fluoride; D055815:Young Adult
chemical_list: D005462:Fluorine Radioisotopes; D012969:Sodium Fluoride; C000615276:Fluorine-18; D002118:Calcium
keywords: 18F-sodium fluoride (18F-NaF); Atherosclerosis; PET/CT; Plaque; Quantification; Vascular calcification