基于光学相干层析成像的投影折射率计算机层析成像系统研制

报道了基于光纤型光学相干层析成像(OCT)的投影折射率计算机层析成像(PICT)系统,并利用研制的系统对外径为1.3 mm,内径为0.9 mm的充水玻璃管样品进行了测量。样品以1°的步进角旋转,共采集180个方向上的投影值,然后利用卷积反投影算法进行了折射率分布图像的重建。实验结果表明,系统具有较高的空间分辨率,能够正确区分空气、玻璃和水三种不同折射率的物质,且其边界清晰可辨;由于利用了折射率信息,投影折射率计算机层析图像消除了常规光学相干层析图像中的几何畸变。

Development of Optical Coherence Tomography Based Projected Index Computed Tomography System

A fiber-typed optical coherence tomography (OCT) based projected index computed tomography(PICT) system is reported.A water-filled glass tube with outer and inner diameters of 1.3 mm and 0.9 mm respectively is measured by the developed system.180 projection data from the sample rotated at step resolution of 1 degree are collected,and its refractive index mapped image is then reconstructed based on convolution back projection algorithm.Experimental result with high spatial resolution shows that air,glass and water with different refractive indexes are properly discriminated and their boundaries are clearly resolved.Meanwhile,due to the utilization of information on refractive index distribution,geometrical distortions usually observed in conventional OCT images are avoided in the PICT image.