title: Reproducibility of CT measurements of aortic valve calcification, mitral annulus calcification, and aortic wall calcification in the multi-ethnic study of atherosclerosis.
abstract: OBJECTIVE
  Extracoronary calcifications may have clinical significance. The error in extracoronary calcification measurements is still unknown. Accurate quantification of calcifications of the aortic valve (AVC), mitral annulus (MAC), and aortic wall (AWC) may be possible by using cardiac computed tomography (CT). We sought to establish the interscan, interobserver, and intraobserver reproducibility of these measures in all cardiac CT scans in the Multi-Ethnic Study of Atherosclerosis.
  
  
  METHODS
  We measured extracoronary calcifications in 100 randomly selected participants to assess interobserver, interscan, and intraobserver variability. Two scans were available for analysis in 99 of these participants, and we quantified thoracic aorta and valvular calcifications.
  
  
  RESULTS
  Mean interscan variability of AVC was 9.7% +/- 11.4% and 8% +/- 10.3% for Agatston and volume scores, with variability of the median at 6.4% and 5.5%, respectively (P > .05). MAC inter-reader variability was 8.2% and 8.9%, with interscan variability of 28% and 33% and intrareader variability of 4% and 4.1%, respectively. For AWC, inter-reader variability was 3%-7.1%, interscan variability was 17%-18%, and intrareader variability was 0.4%-1.4%.
  
  
  CONCLUSIONS
  AVC, MAC, and AWC measurements are sufficiently reproducible to allow serial investigations over a time suitable for clinical studies.
authors.affiliation: Harbor-UCLA Research and Education Institute, Torrance, CA 90502, USA. budoff@ucla.edu
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Budoff
authors.forename: Junichiro
authors.initials: J
authors.lastname: Takasu
authors.forename: Ronit
authors.initials: R
authors.lastname: Katz
authors.forename: Songshou
authors.initials: S
authors.lastname: Mao
authors.forename: David M
authors.initials: DM
authors.lastname: Shavelle
authors.forename: Kevin D
authors.initials: KD
authors.lastname: O'Brien
authors.forename: Roger S
authors.initials: RS
authors.lastname: Blumenthal
authors.forename: J Jeffrey
authors.initials: JJ
authors.lastname: Carr
authors.forename: Richard
authors.initials: R
authors.lastname: Kronmal
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging / Q000473:pathology; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging* / Q000208:ethnology; D002114:Calcinosis / Q000000981:diagnostic imaging* / Q000208:ethnology; D015986:Confounding Factors, Epidemiologic; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000208:ethnology; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D008946:Mitral Valve Stenosis / Q000000981:diagnostic imaging* / Q000208:ethnology; D015588:Observer Variation; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed; D014481:United States / Q000453:epidemiology