Diffusion-weighted (DW) MRI enables qualitative and quantitative assessment of tissue diffusivity. Body diffusion imaging at 3T using conventional single-shot EPI sequence is challenged by respiratory and cardiac motions of subject, limited spatial resolution, and image distortion and ghosting. In this work, a new 3D imaging technique incorporating M1-compensated diffusion preparation and motion-robust stack-of-stars data acquisition was developed. Preliminary volunteer studies demonstrated its feasibility for free-breathing body diffusion imaging at 3T. From one patient underwent MR-PET scan, reduced ADC and increased FDG uptake was observed in the same focal lesion.