Subnanoradian X-ray phase-contrast imaging using a far-field interferometer of nanometric phase gratings

作者：Han Wen, Andrew A. Gomella, Ajay I. Patel, Susanna K. Lynch, Nicole Y. Morgan, Stasia A. Anderson, Eric E. Bennett, Xianghui Xiao, Chian Liu, Douglas E. Wolfe · 发表于：Nature Communications · 年份：2013 · DOI：10.1038/ncomms3659 · 被引用次数：47 · 研究领域：Advanced X-ray Imaging Techniques、Crystallography and Radiation Phenomena、Laser-Plasma Interactions and Diagnostics

Hard X-ray phase-contrast imaging characterizes the electron density distribution in an object without the need for radiation absorption. The power of phase contrast to resolve subtle changes, such as those in soft tissue structures, lies in its ability to detect minute refractive bending of X-rays. Here we report a far-field, two-arm interferometer based on the new nanometric phase gratings, which can detect X-ray refraction with subnanoradian sensitivity, and at the same time overcomes the fundamental limitation of ultra-narrow bandwidths (Δλ/λ~10−4) of the current, most sensitive methods based on crystal interferometers. On a 1.5% bandwidth synchrotron source, we demonstrate clear visualization of blood vessels in unstained mouse organs in simple projection views, with over an order-of-magnitude higher phase contrast than current near-field grating interferometers. Phase-contrast imaging has become popular for medical diagnostic purposes because of the ability to see transparent structures at relatively small radiation energy dosed to samples. Wenet al.further develop this technique using nanometric phase gratings to achieve subnanoradian sensitivity.