title: Reader and platform reproducibility for quantitative assessment of carotid atherosclerotic plaque using 1.5T Siemens, Philips, and General Electric scanners.
abstract: OBJECTIVE
  To evaluate the platform and reader reproducibility of quantitative carotid plaque measurements.
  
  
  METHODS
  A total of 32 individuals with >or=15% carotid stenosis by duplex ultrasound were each imaged once by a 1.5T General Electric (GE) whole body scanner and twice by either a 1.5T Philips scanner or a 1.5T Siemens scanner. A standardized multisequence protocol and identical phased-array carotid coils were used. Expert readers, blinded to subject information, scanner type, and time point, measured the lumen, wall, and total vessel areas and determined the modified American Heart Association lesion type (AHA-LT) on the cross-sectional images.
  
  
  RESULTS
  AHA-LT was consistently identified across the same (kappa = 0.75) and different scan platforms (kappa = 0.75). Furthermore, scan-rescan coefficients of variation (CV) of wall area measurements on Siemens and Philips scanners ranged from 6.3% to 7.5%. However, wall area measurements differed between Philips and GE (P = 0.003) and between Siemens and GE (P = 0.05). In general, intrareader reproducibility was higher than interreader reproducibility for AHA-LT identification as well as for quantitative measurements.
  
  
  CONCLUSIONS
  All three scanners produced images that allowed AHA-LT to be consistently identified. Reproducibility of quantitative measurements by Siemens and Philips scanners were comparable to previous studies using 1.5T GE scanners. However, bias was introduced with each scanner and the use of different readers substantially increased variability. We therefore recommend using the same platform and the same reader for scans of individual subjects undergoing serial assessment of carotid atherosclerosis.
authors.affiliation: Department of Clinical Radiology, University of Munich, Munich, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Saam
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Hatsukami
authors.forename: Vasily L
authors.initials: VL
authors.lastname: Yarnykh
authors.forename: Cecil E
authors.initials: CE
authors.lastname: Hayes
authors.forename: Hunter
authors.initials: H
authors.lastname: Underhill
authors.forename: Baocheng
authors.initials: B
authors.lastname: Chu
authors.forename: Norihide
authors.initials: N
authors.lastname: Takaya
authors.forename: Jianming
authors.initials: J
authors.lastname: Cai
authors.forename: William S
authors.initials: WS
authors.lastname: Kerwin
authors.forename: Dongxiang
authors.initials: D
authors.lastname: Xu
authors.forename: Nayak L
authors.initials: NL
authors.lastname: Polissar
authors.forename: B
authors.initials: B
authors.lastname: Neradilek
authors.forename: Wendy K
authors.initials: WK
authors.lastname: Hamar
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Maki
authors.forename: Dennis W
authors.initials: DW
authors.lastname: Shaw
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Buck
authors.forename: Brad
authors.initials: B
authors.lastname: Wyman
authors.forename: Chun
authors.initials: C
authors.lastname: Yuan
mesh_terms: D000368:Aged; D050197:Atherosclerosis / Q000000981:diagnostic imaging* / Q000473:pathology*; D002339:Carotid Arteries / Q000000981:diagnostic imaging*; D016893:Carotid Stenosis / Q000473:pathology; D003251:Constriction, Pathologic / Q000000981:diagnostic imaging; D004867:Equipment Design; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D014463:Ultrasonography / Q000379:methods; D051598:Whole Body Imaging