基于北京同步辐射装置(BSRF)开展了同轴X射线相位衬度计算机X射线断层摄影术(CT)研究。利用北京同步辐射的14 keV单色X射线作为光源,以高分辨能力的X射线胶片作为探测器,分别开展吸收衬度和同轴相位衬度成像的比较研究以及相位衬度计算机X射线断层摄影术研究。相位衬度计算机X射线断层摄影术重建采用Bronnikov提出的算法。结果显示,与传统的吸收衬度图像相比,相位衬度图像具有更好的衬度和更高的空间分辨力;实验获得人工样品和蝗虫的相位衬度计算机X射线断层摄影术重建图像。重建图像中可见样品的一些结构细节。实验结果表明,相位衬度X射线成像更适合于研究弱吸收或吸收差异很小的材料;利用北京同步辐射开展同轴X射线相位衬度计算机X射线断层摄影术研究是可行的。

To develop the in-line X-ray phase-contrast computerized tomography (CT) method based on synchrotron radiation in Beijing Synchrotron Radiation Facility (BSRF). The comparison studies of in-line phase-contrast imaging with absorption-contrast imaging as well as the technique of in-line phase-contrast computerized tomography were carried out using the 14 keV monochromatic X-ray from BSRF as the light source and the X-ray film with high-resolution power as the detector. The algorithm proposed by Bronnikov was employed for the phase-contrast CT reconstruction. Compared with conventional absorbing-contrast images, phase-contrast images have better contrast and higher spatial resolution. Phase-contrast CT reconstruction images of the experimental samples were acquired and some feature details of the objects could be seen in the reconstruction images. The above experimental results indicate that phase-contrast X-ray imaging method is more applicable to the studies of the materials with weakly absorbing and small absorption difference, and it is feasible to carry out in-line X-ray phase-contrast CT using X-ray source of BSRF.