Multi-system repeatability and reproducibility of apparent diffusion coefficient measurement using an ice-water phantom

J Magn Reson Imaging. 2013 May;37(5):1238-46. doi: 10.1002/jmri.23825. Epub 2012 Sep 28.


Purpose: To determine quantitative quality control procedures to evaluate technical variability in multi-center measurements of the diffusion coefficient of water as a prerequisite to use of the biomarker apparent diffusion coefficient (ADC) in multi-center clinical trials.

Materials and methods: A uniform data acquisition protocol was developed and shared with 18 participating test sites along with a temperature-controlled diffusion phantom delivered to each site. Usable diffusion weighted imaging data of ice water at five b-values were collected on 35 clinical MRI systems from three vendors at two field strengths (1.5 and 3 Tesla [T]) and analyzed at a central processing site.

Results: Standard deviation of bore-center ADCs measured across 35 scanners was <2%; error range: -2% to +5% from literature value. Day-to-day repeatability of the measurements was within 4.5%. Intra-exam repeatability at the phantom center was within 1%. Excluding one outlier, inter-site reproducibility of ADC at magnet isocenter was within 3%, although variability increased for off-center measurements. Significant (>10%) vendor-specific and system-specific spatial nonuniformity ADC bias was detected for the off-center measurement that was consistent with gradient nonlinearity.

Conclusion: Standardization of DWI protocol has improved reproducibility of ADC measurements and allowed identifying spatial ADC nonuniformity as a source of error in multi-site clinical studies.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Diffusion Magnetic Resonance Imaging / instrumentation*
  • Diffusion Magnetic Resonance Imaging / methods*
  • Equipment Failure Analysis / instrumentation
  • Equipment Failure Analysis / standards
  • Ice*
  • Image Interpretation, Computer-Assisted / instrumentation*
  • Image Interpretation, Computer-Assisted / standards*
  • Phantoms, Imaging*
  • Quality Assurance, Health Care
  • Reproducibility of Results
  • Sensitivity and Specificity
  • United States
  • Water*


  • Ice
  • Water