Yamada Y, Hasegawa Y, Yamashita Y
Appl Opt. 1993 Sep 1;32(25):4808-14. doi: 10.1364/AO.32.004808.
Numerical simulations of the transmission of a light impulse through strongly scattering and weakly absorbing slab media and of fan-beam-type optical computed-tomography imaging for cylindrical media are presented. A hybrid calculation scheme of scattering by the Monte Carlo method is employed to obtain the temporal variation of transmittance of the light impulse through the media. A set of projection data is provided by temporally extrapolating the difference in the optical density between the absorbing object and the nonabsorbing reference to the shortest time of flight. For the case of identical scattering between the object and reference, the reconstructed image of the difference in the absorption coefficient has better accuracy and spatial resolution than those images by the time-gating method.
本文给出了光脉冲在强散射弱吸收平板介质中传输以及圆柱介质扇形束型光学计算机断层扫描成像的数值模拟。采用蒙特卡罗方法的混合散射计算方案来获得光脉冲透过介质的透射率随时间的变化。通过将吸收物体与非吸收参考之间的光密度差在时间上外推到最短飞行时间来提供一组投影数据。对于物体与参考之间散射相同的情况，吸收系数差异的重建图像比时间选通方法得到的图像具有更高的精度和空间分辨率。
