X-ray phase tomography with near-field speckles for three-dimensional virtual histology

High-contrast, high-resolution imaging of biomedical specimens is indispensable for studying organ function and pathologies. Conventional histology, the gold standard for soft-tissue visualization, is limited by its anisotropic spatial resolution, elaborate sample preparation, and lack of quantitative image information. X-ray absorption or phase tomography have been identified as promising alternatives enabling non-destructive, distortion-free three-dimensional (3D) imaging. However, reaching sufficient contrast and resolution with a simple experimental procedure remains a major challenge. Here, we present a solution based on x-ray phase tomography through speckle-based imaging (SBI). We demonstrate on a mouse kidney that SBI delivers comprehensive 3D maps of hydrated, unstained soft tissue, revealing its microstructure and delivering quantitative tissue-density values at a density resolution of better than 2 mg/cm(3) and spatial resolution of better than 8 mu m. We expect that SBI virtual histology will find widespread application in biomedicine and will open up new possibilities for research and histopathology. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement