title: Reproducibility of coronary artery calcium measurements using 0.8-mm-thickness 256-slice coronary CT.
abstract: OBJECTIVE
  Coronary artery calcium (CAC) measurement has been utilized as an important indicator of coronary artery disease and predictor of cardiovascular risk. The reproducibility of CAC measurements makes it clinically useful for the assessment of progression and regression of coronary atherosclerosis. This study assessed the reproducibility of the Agatston CAC score among patients undergoing 256-slice multidetector computed tomography (MDCT) scans using 0.8-mm slice thickness.
  
  
  METHODS
  One hundred four patients (aged 62.8 ± 9.0 years, 56.7 % males) with CAC scores >0 on 256-slice MDCT underwent additional MDCT imaging at 2-week intervals. The CAC score was quantified using the Agatston score, which was measured independently by two radiologists.
  
  
  RESULTS
  The variability between observers and MDCT scan measurements was determined by the mean value of absolute and percentage differences: inter-scan/inter-observer (14.45 ± 21.84, 12.51 ± 21.84 %), intra-scan/intra-observer (1.75 ± 5.85, 1.26 ± 3.69 %), intra-scan/inter-observer (3.3 ± 9.1, 4.8 ± 21.3 %), and inter-scan/intra-observer (13.45 ± 20.7, 10.04 ± 10.46 %).
  
  
  CONCLUSIONS
  Reproducibility in CAC measurements using the 0.8-mm-thickness 256-slice MDCT showed low inter-scan/inter-observer variability. Therefore, this CT imaging has potential to be used in prospective, longitudinal CAC assessments.
authors.affiliation: Division of Cardiology, Ulsan University Hospital, University of Ulsan College of Medicine, 290-3 Jeonha-dong, Dong-gu, Ulsan, 682-714, South Korea.
authors.forename: Soe Hee
authors.initials: SH
authors.lastname: Ann
authors.forename: Jae Hee
authors.initials: JH
authors.lastname: Kim
authors.forename: Nam Du
authors.initials: ND
authors.lastname: Ha
authors.forename: Seong Hoon
authors.initials: SH
authors.lastname: Choi
authors.forename: Scot
authors.initials: S
authors.lastname: Garg
authors.forename: Gillian Balbir
authors.initials: GB
authors.lastname: Singh
authors.forename: Eun-Seok
authors.initials: ES
authors.lastname: Shin
mesh_terms: D002114:Calcinosis / Q000000981:diagnostic imaging*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D015588:Observer Variation; D015203:Reproducibility of Results; D012307:Risk Factors