A new phase for X-ray imaging

Abstract

A fine marriage between two approaches to X-ray microscopy — computed tomography and ptychographic imaging — delivers high-resolution, three-dimensional images of samples without the need for lenses. See Letter p. 436 Established X-ray tomography techniques can reveal the three-dimensional internal structure of entire organisms and of single cells, as well as quantitative information, usually calculated from X-ray attenuation data. A newly emerging X-ray computed tomography technique that uses 'ptychographic' X-ray imaging — which can extract detailed phase contrast information from even weakly absorbing objects — is now taking quantitative X-ray imaging into the nanoworld. Sensitive to density variations of less than 1%, the potential of the new method is demonstrated by producing three-dimensional images of a bone specimen in which structures on the 100-nanometre scale, such as the osteocyte lacunae and the interconnective canalicular network, are clearly resolved. High-resolution quantitative tomography of this type may find applications in biomedicine and in microanalysis of fossils as well as in materials science.