title: Comparison between integrated backscatter intravascular ultrasound and 64-slice multi-detector row computed tomography for tissue characterization and volumetric assessment of coronary plaques.
abstract: BACKGROUND
  The purpose of this study was to determine the cut-off values of Hounsfield units (HU) for the discrimination of plaque components and to evaluate the feasibility of measurement of the volume of plaque components using multi-detector row computed tomography (MDCT).
  
  
  METHODS
  Coronary lesions (125 lesions in 125 patients) were visualized by both integrated backscatter intravascular ultrasound (IB-IVUS) and 64-slice MDCT at the same site. The IB values were used as a gold standard to determine the cut off values of HU for the discrimination of plaque components.
  
  
  RESULTS
  Plaques were classified as lipid pool (n =50), fibrosis (n =65) or calcification (n =35) by IB-IVUS. The HU of lipid pool, fibrosis and calcification were 18 ± 18 HU (-19 to 58 HU), 95 ± 24 HU (46 to 154 HU) and 378 ± 99 HU (188 to 605 HU), respectively. Using receiver operating characteristic curve analysis, a threshold of 50 HU was the optimal cutoff values to discriminate lipid pool from fibrosis. Lipid volume measured by MDCT was correlated with that measured by IB-IVUS (r =0.66, p <0.001), whereas fibrous volume was not (r =0.21, p =0.059).
  
  
  CONCLUSIONS
  Lipid volume measured by MDCT was moderately correlated with that measured by IB-IVUS. MDCT may be useful for volumetric assessment of the lipid volume of coronary plaques, whereas the assessment of fibrosis volume was unstable.
authors.affiliation: Department of Cardiology, Gifu University Graduate School of Medicine, Yanagido, Japan.
authors.forename: Takahiko
authors.initials: T
authors.lastname: Yamaki
authors.forename: Masanori
authors.initials: M
authors.lastname: Kawasaki
authors.forename: Ik-Kyung
authors.initials: IK
authors.lastname: Jang
authors.forename: Owen Christopher
authors.initials: OC
authors.lastname: Raffel
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Ishihara
authors.forename: Munenori
authors.initials: M
authors.lastname: Okubo
authors.forename: Tomoki
authors.initials: T
authors.lastname: Kubota
authors.forename: Arihiro
authors.initials: A
authors.lastname: Hattori
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Nishigaki
authors.forename: Genzou
authors.initials: G
authors.lastname: Takemura
authors.forename: Hisayoshi
authors.initials: H
authors.lastname: Fujiwara
authors.forename: Shinya
authors.initials: S
authors.lastname: Minatoguchi
mesh_terms: D000368:Aged; D023921:Coronary Stenosis / Q000175:diagnosis*; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D061330:Multidetector Computed Tomography / Q000379:methods*; D058226:Plaque, Atherosclerotic / Q000150:complications / Q000175:diagnosis*; D012372:ROC Curve; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D018084:Ultrasonography, Interventional / Q000379:methods*