Khimchenko Anna, Schulz Georg, Thalmann Peter, Müller Bert
Biomaterials Science Center, University of Basel, 4123 Allschwil, Switzerland.
APL Bioeng. 2018 Jan 26;2(1):016106. doi: 10.1063/1.5022184. eCollection 2018 Mar.
Visualizing the internal architecture of large soft tissue specimens within the laboratory environment in a label-free manner is challenging, as the conventional absorption-contrast tomography yields a poor contrast. In this communication, we present the integration of an X-ray double-grating interferometer (XDGI) into an advanced, commercially available micro computed tomography system nanotom m with a transmission X-ray source and a micrometer-sized focal spot. The performance of the interferometer is demonstrated by comparing the registered three-dimensional images of a human knee joint sample in phase- and conventional absorption-contrast modes. XDGI provides enough contrast (1.094 ± 0.152) to identify the cartilage layer, which is not recognized in the conventional mode (0.287 ± 0.003). Consequently, the two modes are complementary, as the present XDGI set-up only reaches a spatial resolution of (73 ± 6) m, whereas the true micrometer resolution in the absorption-contrast mode has been proven. By providing complimentary information, XDGI is especially a supportive quantitative method for imaging soft tissues and visualizing weak X-ray absorbing species in the direct neighborhood of stronger absorbing components at the microscopic level.
在实验室环境中以无标记方式可视化大型软组织标本的内部结构具有挑战性，因为传统的吸收对比断层扫描产生的对比度较差。在本通讯中，我们展示了将X射线双光栅干涉仪（XDGI）集成到先进的、市售的微型计算机断层扫描系统nanotom m中，该系统配备透射X射线源和微米级焦点。通过比较在相位和传统吸收对比模式下注册的人类膝关节样本的三维图像，展示了干涉仪的性能。XDGI提供了足够的对比度（1.094±0.152）来识别软骨层，而在传统模式下（0.287±0.003）无法识别该软骨层。因此，这两种模式是互补的，因为目前的XDGI设置仅达到（73±6）μm的空间分辨率，而吸收对比模式下已证明具有真正的微米分辨率。通过提供补充信息，XDGI尤其成为一种用于在微观层面成像软组织和可视化强吸收成分直接邻域中弱X射线吸收物质的支持性定量方法。
