title: (18)F-FDG accumulation in atherosclerotic plaques: immunohistochemical and PET imaging study.
abstract: The rupture of atherosclerotic plaques and the subsequent formation of thrombi are the main factors responsible for myocardial and cerebral infarctions. Thus, the detection of vulnerable plaques in atherosclerotic lesions is a desirable goal, and attempts to image these plaques with (18)F-FDG have been made. In the present study, the relationship between the accumulation of (18)F-FDG and the biologic characteristics of atherosclerotic lesions was investigated. Furthermore, PET imaging of vulnerable plaques was performed with an animal model of atherosclerosis, Watanabe heritable hyperlipidemic (WHHL) rabbits.
  
  
  METHODS
  WHHL (n = 11) and control (n = 3) rabbits were injected intravenously with (18)F-FDG, and the thoracic and abdominal aortas were removed 4 h after injection. The accumulated radioactivity was measured, and the number of macrophages and the intimal area were investigated by examination of stained sections. PET and CT images were also acquired at 210 min after injection of the radiotracer.
  
  
  RESULTS
  (18)F-FDG accumulated to a significantly higher level in the aortas of the WHHL rabbits (mean +/- SD differential uptake ratio [DUR], 1.47 +/- 0.90) than in those of the control rabbits (DUR, 0.44 +/- 0.15); DUR was calculated as (tissue activity/tissue weight)/(injected radiotracer activity/animal body weight), with activities given in becquerels and weights given in kilograms. (18)F-FDG uptake and the number of macrophages were strongly correlated in the atherosclerotic lesions of the WHHL rabbits (R = 0.81). In the PET analysis, intense (18)F-FDG radioactivity was detected in the aortas of the WHHL rabbits, whereas little radioactivity was seen in the control rabbits.
  
  
  CONCLUSIONS
  The results suggest that macrophages are responsible for the accumulation of (18)F-FDG in atherosclerotic lesions. Because vulnerable plaques are rich in macrophages, (18)F-FDG imaging should be useful for the selective detection of such plaques.
authors.affiliation: Department of Investigative Radiology, Research Institute, National Cardiovascular Center, Suita, Japan.
authors.forename: Mikako
authors.initials: M
authors.lastname: Ogawa
authors.forename: Seigo
authors.initials: S
authors.lastname: Ishino
authors.forename: Takahiro
authors.initials: T
authors.lastname: Mukai
authors.forename: Daigo
authors.initials: D
authors.lastname: Asano
authors.forename: Noboru
authors.initials: N
authors.lastname: Teramoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Watabe
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kudomi
authors.forename: Masashi
authors.initials: M
authors.lastname: Shiomi
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Magata
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Iida
authors.forename: Hideo
authors.initials: H
authors.lastname: Saji
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology; D001161:Arteriosclerosis / Q000000981:diagnostic imaging* / Q000378:metabolism* / Q000473:pathology; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D008264:Macrophages / Q000000981:diagnostic imaging* / Q000378:metabolism* / Q000473:pathology; D011817:Rabbits; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014055:Tomography, Emission-Computed / Q000379:methods
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18