Humans and other large organisms are three-dimensional multiscale biological systems where large scale function and structure are dependent on the macrostructure’s interconnectivity down to the cellular and subcellular level. Using the exceptional coherence provided by the ESRF-EBS, we have demonstrated that propagation-based phase-contrast can effectively decouple resolution from specimen size in soft tissue, obtaining 1.4 micron voxel resolution in 150 mm diameter human organs. Through this Long Term Proposal (LTP) we will develop the techniques required to image whole human and animal bodies ex vivo at 25 micron resolution, zooming to sub-micron voxels (0.7micron) locally, resolving sub-cellular structures through hard- and soft-tissue. Resolving how the micro (sub-cellular) interacts with the macro (whole organism) across length scales will provide all new insights into biological and biomedical function. This is true for both healthy and pathological system level behaviour.