Naomi H. M. Douglas1, Jessica M. Winfield1, Nandita M. deSouza1, David John Collins1, Matthew R. Orton1
1Radiotherapy and Imaging, Institute of Cancer Research, Sutton, Surrey, United Kingdom
Temperature-controlled phantoms containing controlled sucrose solutions were used to measure the Apparent Diffusion Coefficient at five European imaging centres. Matched Diffusion-Weighted (DW) MR sequences were applied across three scanner manufacturers. Repeat measurements were acquired over a 6-month period. Inter-site comparison revealed differences in scanner accuracy, precision and stability. Artefacts were identified including spatial variations in ADC of a uniform test object, prompting a recommendation that reproducible subject positioning is ensured in tests of diffusion parameter reproducibility. Results from systems without identifiable artefact suggest that an ADC coefficient of variation of less than 2% is achievable with well controlled scanner set-up.