title: Discrepancy of calcium detection between gray scale intravascular ultrasound and spectral analysis of radiofrequency data.
abstract: BACKGROUND
  We evaluated discrepancy of calcium detection between gray scale intravascular ultrasound (IVUS) and virtual histology (VH)-IVUS and the association between coronary calcium and plaque composition.
  
  
  METHODS
  Study population consisted of 162 consecutive patients who underwent percutaneous coronary intervention with VH-IVUS study. Subjects were divided into 3 groups based on gray scale IVUS findings; No calcification group (n=50), spotty group (n=56) who had a lesion containing only small calcium deposits within an arc <90° and diffuse group (n=56) who had a diffuse calcified lesion with an arc ≥ 90° in ≥ 1 cross-sectional image of the lesion.
  
  
  RESULTS
  No calcification group was younger than spotty and diffuse groups (54.4 ± 13.0 years vs. 61.1 ± 10.7 years and 64.2 ± 9.9 years, p=0.011 and p<0.001, respectively). No calcification group had some degree of dense calcium (5. 7 ± 6.9 mm(3)) by VH-IVUS analysis. Furthermore, calcified volume by VH-IVUS in no calcification group was similar to those in spotty group (5.7 ± 6.9 mm(3) vs. 5.4 ± 4.4mm(3)). Dense calcium volume was correlated directly with plaque volume (r=0.65, p<0.001), fibrous volume (r=0.54, p<0.001), fibro-fatty volume (r=0.29, p<0.001) and lipid core volume (r=0.77, p<0.001). In multiple regression analysis, lipid core volume (β=0.287, 95% confidence interval (CI) 0.187-0.388, p<0.001) was an independent predictor of dense calcium volume.
  
  
  CONCLUSIONS
  This study showed that coronary calcium can be present even if invisible in gray scale IVUS and associated with lipid core volume, which is a characteristic of plaque vulnerability.
authors: Cardiology, Heart Center, Konyang University Hospital, Daejeon, South Korea.
authors: Taek-Geun
authors: TG
authors: Kwon
authors: Young Hoon
authors: YH
authors: Seo
authors: Chung Seop
authors: CS
authors: Lee
authors: Dong-Ju
authors: DJ
authors: Yang
authors: In Girl
authors: IG
authors: Song
authors: Hyun-Woong
authors: HW
authors: Park
authors: Ki Hong
authors: KH
authors: Kim
authors: Wan-Ho
authors: WH
authors: Kim
authors: Jang-Ho
authors: JH
authors: Bae
mesh_terms: D000328:Adult; D000368:Aged; D002118:Calcium / Q000032:analysis; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D062645:Percutaneous Coronary Intervention / Q000379:methods; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging / Q000601:surgery; D018084:Ultrasonography, Interventional / Q000379:methods*; D061205:Vascular Calcification / Q000000981:diagnostic imaging* / Q000601:surgery
chemical_list: D002118:Calcium