title: Assessment of coronary calcification using calibrated mass score with two different multidetector computed tomography scanners in the Copenhagen General Population Study.
abstract: OBJECTIVE
  Population studies have shown coronary calcium score to improve risk stratification in subjects suspected for cardiovascular disease. The aim of this work was to assess the validity of multidetector computed tomography (MDCT) for measurement of calibrated mass scores (MS) in a phantom study, and to investigate inter-scanner variability for MS and Agaston score (AS) recorded in a population study on two different high-end MDCT scanners.
  
  
  METHODS
  A calcium phantom was scanned by a first (A) and second (B) generation 320-MDCT. MS was measured for each calcium deposit from repeated measurements in each scanner and compared to known physical phantom mass. Random samples of human subjects from the Copenhagen General Population Study were scanned with scanner A (N=254) and scanner B (N=253) where MS and AS distributions of these two groups were compared.
  
  
  RESULTS
  The mean total MS of the phantom was 32.9±0.8mg and 33.1±0.9mg (p=0.43) assessed by scanner A and B respectively - the physical calcium mass was 34.0mg. Correlation between measured MS and physical calcium mass was R2=0.99 in both scanners. In the population study the median total MS was 16.8mg (interquartile range (IQR): 3.5-81.1) and 15.8mg (IQR: 3.8-63.4) in scanner A and B (p=0.88). The corresponding median total AS were 92 (IQR: 23-471) and 89 (IQR: 40-384) (p=0.64).
  
  
  CONCLUSIONS
  Calibrated calcium mass score may be assessed with very high accuracy in a calcium phantom by different generations of 320-MDCT scanners. In population studies, it appears acceptable to pool calcium scores acquired on different 320-MDCT scanners.
authors.affiliation: Department of Cardiology, The Heart Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Andreas
authors.initials: A
authors.lastname: Fuchs
authors.affiliation: Department of Radiology, University of Groningen, University Medical Center Groningen, The Netherlands; Department of Medical Physics, OLVG, Amsterdam, the Netherlands.
authors.forename: Jaap M
authors.initials: JM
authors.lastname: Groen
authors.affiliation: Image Analysis, 1380 Burkesville Road, Columbia, KY, USA.
authors.forename: Ben A
authors.initials: BA
authors.lastname: Arnold
authors.affiliation: Department of Radiology, University of Groningen, University Medical Center Groningen, The Netherlands.
authors.forename: Sasho
authors.initials: S
authors.lastname: Nikolovski
authors.affiliation: Department of Cardiology, The Heart Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark. Electronic address: dehlbaek@gmail.com.
authors.forename: Andreas D
authors.initials: AD
authors.lastname: Knudsen
authors.affiliation: Department of Cardiology, The Heart Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
authors.forename: J Tobias
authors.initials: JT
authors.lastname: Kühl
authors.affiliation: Department of Clinical Biochemistry and the Copenhagen General Population Study, Herlev Hospital, University of Copenhagen, Denmark.
authors.forename: Børge G
authors.initials: BG
authors.lastname: Nordestgaard
authors.affiliation: Department of Radiology, University of Groningen, University Medical Center Groningen, The Netherlands.
authors.forename: Marcel J W
authors.initials: MJ
authors.lastname: Greuter
authors.affiliation: Department of Cardiology, The Heart Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark; Department of Radiology, The Diagnostic Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Klaus F
authors.initials: KF
authors.lastname: Kofoed
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002114:Calcinosis / Q000150:complications* / Q000000981:diagnostic imaging; D002138:Calibration; D003324:Coronary Artery Disease / Q000150:complications / Q000000981:diagnostic imaging*; D003718:Denmark; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000295:instrumentation* / Q000379:methods*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D015898:Tomography Scanners, X-Ray Computed
keywords: Agatston; Calcium; MDCT; Mass score; Multidetector computed tomography; Population