title: Coronary calcium scoring from contrast coronary CT angiography using a semiautomated standardized method.
abstract: BACKGROUND
  When coronary calcium scoring is performed in patients with suspected coronary artery disease, a separate noncontrast scan is acquired before contrast-enhanced coronary CT angiography (CTA).
  
  
  OBJECTIVE
  Our aim was to develop and validate an automated method for calculating the coronary calcium score (CCS) from coronary CTA.
  
  
  METHODS
  We analyzed coronary CTA and noncontrast CT data sets of 84 patients (Agatston score >0). The CCS on noncontrast CT was measured using commercial methods. Coronary calcium volume was measured on coronary CTA using an automated standardized method with scan-specific calcium thresholds. Data sets were split into derivation (n = 40) and validation groups (n = 44). To calculate the CCS on coronary CTA, a conversion factor between calcium scores measured in noncontrast CT and the calcium volume measured on coronary CTA was derived by linear regression.
  
  
  RESULTS
  In the validation group, the median calculated CCS derived from CTA was 277 and 244 on noncontrast images (P = .12). This CCS showed an excellent correlation with the CCS from noncontrast images (Pearson, r = 0.95). In the validation group, 39 of 44 patients (88.6%) were classified into the same standard category (1-10, 11-100, 101-400, or >400) with an excellent agreement (weighted κ of 0.87).
  
  
  CONCLUSIONS
  CCSs can be accurately measured from contrast-enhanced coronary CTA by using an automated, standardized method, obviating the need for a noncontrast scan.
authors.affiliation: Department of Cardiology, University of Erlangen, Ulmenweg 18, Erlangen 91054, Germany. Electronic address: annika.schuhbaeck@uk-erlangen.de.
authors.forename: Annika
authors.initials: A
authors.lastname: Schuhbaeck
authors.affiliation: Department of Imaging and Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Otaki
authors.affiliation: Department of Cardiology, University of Erlangen, Ulmenweg 18, Erlangen 91054, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Achenbach
authors.affiliation: Department of Radiology, University of Giessen, Giessen, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Schneider
authors.affiliation: Department of Imaging and Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
authors.forename: Piotr
authors.initials: P
authors.lastname: Slomka
authors.affiliation: Department of Imaging and Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Berman
authors.affiliation: Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
authors.forename: Damini
authors.initials: D
authors.lastname: Dey
mesh_terms: D000368:Aged; D001331:Automation; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D005260:Female; D005858:Germany; D006801:Humans; D015141:Los Angeles; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D012984:Software; D014057:Tomography, X-Ray Computed / Q000379:methods*; D061205:Vascular Calcification / Q000000981:diagnostic imaging*
keywords: Automated quantification; CT angiography; Computed tomography; Coronary calcified plaque; Coronary calcium score