title: Diffusion coefficient measurement using a temperature-controlled fluid for quality control in multicenter studies.
abstract: OBJECTIVE
  To present the use of a quality control ice-water phantom for diffusion-weighted magnetic resonance imaging (DW-MRI). DW-MRI has emerged as an important cancer imaging biomarker candidate for diagnosis and early treatment response assessment. Validating imaging biomarkers through multicenter trials requires calibration and performance testing across sites.
  
  
  METHODS
  The phantom consisted of a center tube filled with distilled water surrounded by ice water. Following preparation of the phantom, ≈30 minutes was allowed to reach thermal equilibrium. DW-MRI data were collected at seven institutions, 20 MRI scanners from three vendors, and two field strengths (1.5 and 3T). The phantom was also scanned on a single system on 16 different days over a 25-day period. All data were transferred to a central processing site at the University of Michigan for analysis.
  
  
  RESULTS
  Results revealed that the variation of measured apparent diffusion coefficient (ADC) values between all systems tested was ±5%, indicating excellent agreement between systems. Reproducibility of a single system over a 25-day period was also found to be within ±5% ADC values. Overall, the use of an ice-water phantom for assessment of ADC was found to be a reasonable candidate for use in multicenter trials.
  
  
  CONCLUSIONS
  The ice-water phantom described here is a practical and universal approach to validate the accuracy of ADC measurements with ever changing MRI sequence and hardware design and can be readily implemented in multicenter clinical trial designs.
authors.affiliation: Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA. tlchenev@umich.edu
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Chenevert
authors.forename: Craig J
authors.initials: CJ
authors.lastname: Galbán
authors.forename: Marko K
authors.initials: MK
authors.lastname: Ivancevic
authors.forename: Susan E
authors.initials: SE
authors.lastname: Rohrer
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Londy
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Kwee
authors.forename: Charles R
authors.initials: CR
authors.lastname: Meyer
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Johnson
authors.forename: Alnawaz
authors.initials: A
authors.lastname: Rehemtulla
authors.forename: Brian D
authors.initials: BD
authors.lastname: Ross
mesh_terms: D000704:Analysis of Variance; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D007053:Ice; D015337:Multicenter Studies as Topic; D019047:Phantoms, Imaging; D011786:Quality Control; D015203:Reproducibility of Results
chemical_list: D007053:Ice