基于毛细管分光的同步辐射X射线立体成像

Synchrotron Radiation X-Ray Stereo Imaging Based on Capillary Beam Splitting

建立了一种基于同步辐射X射线的立体成像系统用于上海光源成像线站(BL13W)。该系统使用两个弯曲毛细管将同步辐射光引出并分为交叉的两束光,实验样品置于两束X射线交叉的位置,在其后一定距离处用成像探测器记录样品的两个投影。根据视差方程和相应算法计算出样品各组分的深度信息,得到样品的伪三维图像。与X射线计算机断层扫描技术相比,该方法成像的时间分辨率大大提升甚至接近单次曝光的时间,可以进行实时成像,并降低了样品受辐射的剂量。选用老鼠肝脏毛细血管的投影图像进行数值模拟,得到了理想的模拟效果。选取螺旋形金属丝在搭建的实验平台上进行立体成像,得到了初步的实验结果。螺旋形金属丝的立体信息可以清楚辨认。

A stereo imaging system based on synchrotron radiation X-rays is built in the BL13 W beam line of the Shanghai Synchrotron Radiation Facility.The system uses two bending capillary tubes to extract synchrotron radiation photons and divides them into two intersected beams.The experimental sample is placed at the intersection of two Xray beams and two projections of the sample are recorded simultaneously by a detector placed close to the sample.The depth information of each element of the sample is calculated by parallax equations and relevant algorithms,and the pseudo three-dimensional image of the sample is produced.Compared with X-ray computed tomography,the proposed method improves the time resolution notably,which is even close to the duration of a single exposure.It can be used for real-time imaging and reduce the radiation dose of the sample.A numerical simulation is performed with the projection of blood capillary in the mouse liver and achieves an ideal result.A spiral wire model is then taken as a sample to conduct stereo imaging in the experimental platform.The preliminary experimental result demonstrates that the stereo information of the spiral wire can be recognized clearly.