title: Feasibility of in vivo, multicontrast-weighted MR imaging of carotid atherosclerosis for multicenter studies.
abstract: OBJECTIVE
  To test the image quality (ImQ) and interscan coverage of MRI for measuring carotid atherosclerosis across multiple centers.
  
  
  METHODS
  Thirty-nine subjects from five clinical sites (site 1: n=11; site 2: n=16; site 3: n=2; site 4: n=3; site 5: n=7) were imaged on GE 1.5T scanners using a standardized carotid imaging protocol with five weightings (T1, proton density (PD), T2, time-of-flight (TOF), and contrast-enhanced (CE) T1). MR technologists from the five sites received comprehensive protocol training. A maximum coverage of 24 mm (12 slices) was designed for each of four scans (baseline and at four, eight, and 13 weeks). The adequacy of coverage was calculated as the percentage of arteries with at least six slices matched across all four scans. ImQ was evaluated using an established five-point scale for each image. ImQ>or= 3 was considered acceptable for image analysis.
  
  
  RESULTS
  Across five sites, the mean ImQ was 3.4-4.2 for T1W, 3.6-4.4 for CE-T1W, 3.4-4.2 for PDW, 3.3-4.2 for T2W, and 3.4-4.0 for TOF. The mean ImQ per site was 3.5-4.2. All sites generated at least six-slice coverage (mean=8.0-9.1) for all index carotid arteries.
  
  
  CONCLUSIONS
  The ImQ and coverage values were comparable among clinical sites using a standardized carotid imaging protocol. With comprehensive protocol training, carotid MRI is technically feasible for use in multicenter studies.
authors.affiliation: Department of Radiology, University of Washington, Seattle, Washington 98195, USA. chubc@u.washington.edu
authors.forename: Baocheng
authors.initials: B
authors.lastname: Chu
authors.forename: Xue-Qiao
authors.initials: XQ
authors.lastname: Zhao
authors.forename: Tobias
authors.initials: T
authors.lastname: Saam
authors.forename: Vasily L
authors.initials: VL
authors.lastname: Yarnykh
authors.forename: William S
authors.initials: WS
authors.lastname: Kerwin
authors.forename: Kelly D
authors.initials: KD
authors.lastname: Flemming
authors.forename: John
authors.initials: J
authors.lastname: Huston
authors.forename: William
authors.initials: W
authors.lastname: Insull
authors.forename: Joel D
authors.initials: JD
authors.lastname: Morrisett
authors.forename: Scott D
authors.initials: SD
authors.lastname: Rand
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: DeMarco
authors.forename: Nayak L
authors.initials: NL
authors.lastname: Polissar
authors.forename: Niranjan
authors.initials: N
authors.lastname: Balu
authors.forename: Jianming
authors.initials: J
authors.lastname: Cai
authors.forename: Annette
authors.initials: A
authors.lastname: Kampschulte
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Hatsukami
authors.forename: Chun
authors.initials: C
authors.lastname: Yuan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002340:Carotid Artery Diseases / Q000175:diagnosis*; D003287:Contrast Media; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results
chemical_list: D003287:Contrast Media