title: Magnetic resonance imaging features of vulnerable plaques in an atherosclerotic rabbit model.
abstract: BACKGROUND
  Noninvasive detection of vulnerable plaque has a significant implication for prevention and treatment of atherosclerotic diseases. The aim of this study is to investigate the difference between vulnerable plaques and stable plaques in magnetic resonance (MR) images.
  
  
  METHODS
  Atherosclerosis was induced in twenty male New Zealand white rabbits by high cholesterol diet and balloon injury of the abdominal aorta. After baseline (pre-triggering) MR imaging (MRI) scan, the rabbits underwent pharmaceutical triggering with Russell's viper venom and histamine to induce atherothrombosis, followed by another MRI scan 48 hours later (post-triggering). Rabbits were euthanized to obtain pathological and histological data. The results of MRI were compared with those of pathology and histology.
  
  
  RESULTS
  MRI showed that abdominal aorta of the rabbits had pathological change of atherosclerosis in different degrees. Seventy-five plaques were analysed, among which 14 had vulnerable thrombi and 61 stable. Thrombosis was identified in 7 of 11 rabbits by post-triggering MRI, the sensitivity and K value of MR in detection of vulnerable plaque was 71% and 0.803 (P < 0.05). MRI data significantly correlated with the histopathological data in fibrous cap thickness (r = 0.749) plaque area (r = 0.853), lipid core area (r = 0.900). Compared with stable plaques, vulnerable plaques had a significantly thinner fibrous cap ((0.58 ± 0.27) mm vs. (0.95 ± 0.22) mm), larger lipid core area ((7.56 ± 2.78) mm(2) vs. (3.29 ± 1.75) mm(2)), and a higher ratio of lipid core area/plaque area ((55 ± 16)% vs. (27 ± 17)%), but plaque area was comparable in two groups on MRI. The ratio of lipid core area/plaque area was a strong predictor of vulnerable plaques.
  
  
  CONCLUSIONS
  MRI could distinguish vulnerable plaques from stable plaques in a rabbit model of atherothrombosis and may thus be useful as a noninvasive modality for detection of vulnerable plaques in humans.
authors.affiliation: Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
authors.forename: Xue-cheng
authors.initials: XC
authors.lastname: Zhao
authors.forename: Quan-ming
authors.initials: QM
authors.lastname: Zhao
authors.forename: Xiao-hai
authors.initials: XH
authors.lastname: Ma
authors.forename: Cong-he
authors.initials: CH
authors.lastname: Zeng
authors.forename: Ting-ting
authors.initials: TT
authors.lastname: Feng
authors.forename: Xin
authors.initials: X
authors.lastname: Zhao
authors.forename: Zhao-qi
authors.initials: ZQ
authors.lastname: Zhang
authors.forename: Ming-duo
authors.initials: MD
authors.lastname: Zhang
authors.forename: Xu-cui
authors.initials: XC
authors.lastname: Zhuang
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000473:pathology; D004195:Disease Models, Animal; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D058226:Plaque, Atherosclerotic / Q000473:pathology*; D011817:Rabbits; D013927:Thrombosis / Q000175:diagnosis