On the cusp of x-ray tomographic mapping of the human brain and its 10^11 cells

The human brain contains 86 billion cells, but so far only a part could be visualized. The task corresponds to the acquisition and treatment of a petabyte-size dataset – analogous to plotting every star in the Milky Way. We demonstrated the feasibility of cellular-resolution full-brain imaging for ethanol-immersed and paraffin-embedded human brain using the tomography setup at the beamline P07 (PETRA III, DESY, Hamburg, Germany), which is operated by the Helmholtz-Zentrum Hereon. Because the beam size and the number of detector pixels limit the field-of-view to 6mm, we decided to stitch these radiographs to projections 90,000 pixels wide. The reconstructed slices allow for the detection of cells, although they contain severe artefacts. The next challenge is the optimization of the data acquisition, so that an entire brain can be made visible using typical beamtime applications. Reconstruction, artefact removal, and dissemination of such a human brain atlas is a task we are faced to. It will create a paradigm for investigating other human organs, high-performance engineering devices, and unique cultural heritage objects related to data of terabyte or even petabyte size.