Matthew D. Blackledge1, Nina Tunariu1, David John Collins1, Anwar R. Padhani2, Martin O. Leach1, Dow M. Koh1
1CRUK and EPSRC Cancer Imaging Centre, Institute of Cancer Research, Sutton, Surrey, United Kingdom; 2Paul Strickland Scanner Centre, Mount Vernon Hospital, Northwood, Middlesex, United Kingdom
We derive the intra-observer repeatability (Bland-Altman statistics) of two radiologists reporting median ADC and total diffusion volume estimates derived from whole-body diffusion-weighted imaging (WBDWI) in a cohort of nine patients with bone metastases. Good repeatability in the range -13.5 to 15.6% is found for ADC estimates and -44.2% to 79.3% for volume estimates. Clinical changes of these parameters in response to treatment are shown to be greater than the repeatability limits observed, as demonstrated in a pilot cohort of 13 patients with bone metastases.