- Diffusion weighted imaging The protocol will requires some technical development and optimisation at the start of the study. This will be undertaken in collaboration with Dr Alan Bainbridge. 2-3 b values (e.g. 50, 100, 300) will be used for the DWI sequences. Anatomical stations will include feet, knees, hips/pelvis and spine (TMJ to pelvis); the shaft of the femur and tibia will be omitted. Image quality is likely to be poor in the arms so these may not be imaged using dedicated sequences. STIR (short tau inversion recovery) methods will be used for fat suppression in the feet, knees and hips.