title: Correlation of inflammation assessed by 18F-FDG PET, active mineral deposition assessed by 18F-fluoride PET, and vascular calcification in atherosclerotic plaque: a dual-tracer PET/CT study.
abstract: Formation and progression of atherosclerotic plaque is a dynamic and complex process involving various pathophysiologic steps including inflammation and calcification. The purpose of this study was to compare macrophage activity as determined by (18)F-FDG PET and ongoing mineral deposition as measured by (18)F-sodium fluoride PET in atherosclerotic plaque and to correlate these findings with calcified plaque burden as assessed by CT.
  
  
  METHODS
  Forty-five patients were examined by whole-body (18)F-FDG PET, (18)F-sodium fluoride PET, and CT. Tracer uptake in various arterial segments was analyzed both qualitatively and semiquantitatively by measuring the blood-pool-corrected standardized uptake value (target-to-background ratio [TBR]). The pattern of tracer uptake in atherosclerotic lesions was compared after color-coded multistudy image fusion of PET and CT studies. The Fisher exact test and the Spearman correlation coefficient r(s) were used for statistical analysis of image-based results and cardiovascular risk factors. Intra- and interrater reproducibility were evaluated using the Cohen κ.
  
  
  RESULTS
  (18)F-sodium fluoride uptake was observed at 105 sites in 27 (60%) of the 45 study patients, and mean TBR was 2.3 ± 0.7. (18)F-FDG uptake was seen at 124 sites in 34 (75.6%) patients, and mean TBR was 1.5 ± 0.3. Calcified atherosclerotic lesions were observed at 503 sites in 34 (75.6%) patients. Eighty-one (77.1%) of the 105 lesions with marked (18)F-sodium fluoride uptake and only 18 (14.5%) of the 124 lesions with (18)F-FDG accumulation were colocalized with arterial calcification. Coincident uptake of both (18)F-sodium fluoride and (18)F-FDG was observed in only 14 (6.5%) of the 215 arterial lesions with radiotracer accumulation.
  
  
  CONCLUSIONS
  PET/CT with (18)F-FDG and (18)F-sodium fluoride may allow evaluation of distinct pathophysiologic processes in atherosclerotic lesions and might provide information on the complex interactions involved in formation and progression of atherosclerotic plaque.
authors.affiliation: Department of Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. t.derlin@uke.uni-hamburg.de
authors.forename: Thorsten
authors.initials: T
authors.lastname: Derlin
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Tóth
authors.forename: László
authors.initials: L
authors.lastname: Papp
authors.forename: Christian
authors.initials: C
authors.lastname: Wisotzki
authors.forename: Ivayla
authors.initials: I
authors.lastname: Apostolova
authors.forename: Christian R
authors.initials: CR
authors.lastname: Habermann
authors.forename: Janos
authors.initials: J
authors.lastname: Mester
authors.forename: Susanne
authors.initials: S
authors.lastname: Klutmann
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography; D001158:Arteries / Q000378:metabolism; D001692:Biological Transport; D002114:Calcinosis / Q000000981:diagnostic imaging*; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism; D006801:Humans; D007249:Inflammation / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D008903:Minerals / Q000378:metabolism*; D058226:Plaque, Atherosclerotic / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000378:metabolism; D049268:Positron-Emission Tomography; D011849:Radioactive Tracers; D012189:Retrospective Studies; D012307:Risk Factors; D012969:Sodium Fluoride / Q000378:metabolism; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D005462:Fluorine Radioisotopes; D008903:Minerals; D011849:Radioactive Tracers; D019788:Fluorodeoxyglucose F18; D012969:Sodium Fluoride