title: Can non-calcified coronary artery plaques be detected on non-contrast CT calcium scoring studies?
abstract: OBJECTIVE
  Coronary computed tomographic (CT) angiography has been shown to detect noncalcified coronary artery plaque. Depending on tissue composition, noncalcified plaque differs in CT attenuation from blood and epicardial fat. The aim of this study was to determine whether noncalcified plaque can be visually detected on non-contrast-enhanced CT calcium scoring studies.
  
  
  METHODS
  A total of 106 patients (40 women; mean age, 59 years) who underwent coronary calcium scoring, coronary CT angiography, and quantitative catheter angiography were prospectively investigated. Two blinded observers independently reviewed calcium scoring studies for positive vascular remodeling and hypoattenuation within the vessel wall, suggestive of noncalcified plaque. Findings on calcium scoring studies were compared with those on coronary CT angiography and quantitative catheter angiography.
  
  
  RESULTS
  The mean Agatston score was 515.8 ± 826.8. Overall interobserver agreement for the identification of noncalcified lesions was substantial (κ = 0.69). Observer 1 and observer 2 identified 21 and 17 patients, respectively, with 38 and 35 lesions suggestive of noncalcified plaque. Coronary CT angiography confirmed noncalcified plaque in 33 of 38 (86.8%; observer 1) and 31 of 35 (88.6%; observer 2) lesions. Thus, the overall positive predictive value for correct identification of noncalcified plaque on calcium scoring studies was 0.88, although overall sensitivity was low at 0.39.
  
  
  CONCLUSIONS
  Noncalcified plaque can be visually detected on calcium scoring studies. Review of calcium scoring studies for features of noncalcified plaque may enhance the identification of patients with more active disease and higher cardiovascular risk.
authors.affiliation: Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC 29401, USA. chthilo@gmail.com
authors.forename: Christian
authors.initials: C
authors.lastname: Thilo
authors.forename: Mulugeta
authors.initials: M
authors.lastname: Gebregziabher
authors.forename: Florian B
authors.initials: FB
authors.lastname: Mayer
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Berghaus
authors.forename: Peter L
authors.initials: PL
authors.lastname: Zwerner
authors.forename: U Joseph
authors.initials: UJ
authors.lastname: Schoepf
mesh_terms: D000328:Adult; D000368:Aged; D002114:Calcinosis / Q000150:complications* / Q000000981:diagnostic imaging*; D003287:Contrast Media; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media