title: Spiral versus electron-beam CT for coronary artery calcium scoring.
abstract: OBJECTIVE
  To determine differences in coronary artery calcium detection, quantification, and reproducibility, as measured at electron-beam computed tomography (CT) and subsecond spiral CT with retrospective electrocardiogram gating in an asymptomatic adult population.
  
  
  METHODS
  Seventy subjects asymptomatic for coronary heart disease underwent both electron-beam CT and subsecond spiral CT. In all subjects, two images each were obtained with both scanners. Two experienced readers using three different algorithms scored each of the four scans: one score for the electron-beam CT images and two scores for the spiral CT images.
  
  
  RESULTS
  With a 130-HU threshold for the quantification of calcium, there were no significant differences in interscan and interobserver variation in calcium scores between the electron-beam CT and spiral CT images. There was greater interobserver (P <.001) and interscan (P <.03) variation in scores when a 90-HU threshold was used for spiral CT images. With a 130-HU threshold, when calcium scores were used for clinical risk stratification, there was a significant difference between the results obtained with electron-beam CT and those obtained with spiral CT (P <.05).
  
  
  CONCLUSIONS
  Spiral CT has not yet proved to be a feasible alternative to electron-beam CT for coronary artery calcium quantification. There are systematic differences between calcium scores obtained with single-detector array subsecond spiral CT and those obtained with electron-beam CT.
authors.affiliation: Department of Radiological Sciences, UCLA School of Medicine, 10833 Le Conte Ave, CHS B2-200, Los Angeles, CA 90095-1721, USA. jgoldin@mednet.ucla.edu
authors.forename: J G
authors.initials: JG
authors.lastname: Goldin
authors.forename: H C
authors.initials: HC
authors.lastname: Yoon
authors.forename: L E
authors.initials: LE
authors.lastname: Greaser
authors.forename: S B
authors.initials: SB
authors.lastname: Heinze
authors.forename: M M
authors.initials: MM
authors.lastname: McNitt-Gray
authors.forename: M S
authors.initials: MS
authors.lastname: Brown
authors.forename: J W
authors.initials: JW
authors.lastname: Sayre
authors.forename: A M
authors.initials: AM
authors.lastname: Emerick
authors.forename: D R
authors.initials: DR
authors.lastname: Aberle
mesh_terms: D000328:Adult; D000368:Aged; D002118:Calcium / Q000032:analysis*; D017023:Coronary Angiography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D002118:Calcium