title: Focal arterial inflammation precedes subsequent calcification in the same location: a longitudinal FDG-PET/CT study.
abstract: BACKGROUND
  Arterial calcium (Ca) deposition has been identified as an active inflammatory process. We sought to test the hypothesis that local vascular inflammation predisposes to subsequent arterial calcium deposition in humans.
  
  
  RESULTS
  From a hospital database, we identified 137 patients (age, 61 ± 13 years; 48.1% men) who underwent serial positron-emission tomography/computed tomography (1-5 years apart). Focal arterial inflammation was prospectively determined by measuring 18F-flourodeoxyglucose uptake (using baseline positron-emission tomography) within predetermined locations of the thoracic aortic wall and was reported as a standardized uptake value. A separate, blinded investigator evaluated calcium deposition (on the baseline and follow-up computed tomographic scans) along the same standardized sections of the aorta. New calcification was prospectively defined using square root-transformed difference of calcium volume score, with a cutoff value of 2.5. Accordingly, vascular segment was classified as either with or without subsequent calcification. Overall, 67 (9%) of aortic segments demonstrated subsequent calcification. Baseline median (interquartile range) standardized uptake value was higher in segments with versus without subsequent calcification (2.09 [1.84-2.44] versus 1.92 [1.72-2.20], P=0.002). This was also true in the subset of segments with Ca present at baseline (2.08 [1.81-2.40] versus 1.86 [1.66-2.09], P=0.02), as well as those without (2.17 [1.87-2.51] versus 1.93 [1.73-2.20], P=0.04). Furthermore, across all patients, subsequent Ca deposition was associated with the underlying 18F-flourodeoxyglucose uptake (inflammatory signal), measured as standardized uptake value (odds ratio [95% confidence interval]=2.94 [1.27-6.89], P=0.01) or target-to-background ratio (2.59 [1.18-5.70], =0.02), after adjusting for traditional cardiovascular risk factors.
  
  
  CONCLUSIONS
  Here, we provide first-in-man evidence that arterial inflammation precedes subsequent Ca deposition, a marker of plaque progression, within the underlying location in the artery wall.
authors.affiliation: Cardiac MR PET CT Program, Division of Cardiology, and Department of Radiology, Massachusetts General Hospital, Boston, MA.
authors.forename: Amr
authors.initials: A
authors.lastname: Abdelbaky
authors.forename: Erin
authors.initials: E
authors.lastname: Corsini
authors.forename: Amparo L
authors.initials: AL
authors.lastname: Figueroa
authors.forename: Sara
authors.initials: S
authors.lastname: Fontanez
authors.forename: Sharath
authors.initials: S
authors.lastname: Subramanian
authors.forename: Maros
authors.initials: M
authors.lastname: Ferencik
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Brady
authors.forename: Udo
authors.initials: U
authors.lastname: Hoffmann
authors.forename: Ahmed
authors.initials: A
authors.lastname: Tawakol
mesh_terms: D000328:Adult; D000368:Aged; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging*; D001025:Aortitis / Q000000981:diagnostic imaging*; D001027:Aortography / Q000379:methods; D016009:Chi-Square Distribution; D018450:Disease Progression; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D015999:Multivariate Analysis; D015588:Observer Variation; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D059629:Signal-To-Noise Ratio; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D061205:Vascular Calcification / Q000000981:diagnostic imaging*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: arterial inflammation; positron-emission tomography; vascular calcification