Schmidt F E, Hebden J C, Hillman E M, Fry M E, Schweiger M, Dehghani H, Delpy D T, Arridge S R
University College London, United Kingdom.
Appl Opt. 2000 Jul 1;39(19):3380-7. doi: 10.1364/ao.39.003380.
Following several years of development the construction of a multichannel time-resolved imaging device for medical optical tomography has been completed. Images are reconstructed from time-resolved measurements by use of a scheme that employs a finite-element diffusion-based forward model and an iterative reconstruction solver. Prior to testing on clinical subjects the fully automated instrument and the reconstruction software are evaluated with tissue-equivalent phantoms. We describe our first attempt to generate multiple-slice images of a phantom without uniform properties along the axial direction, while still using a computationally fast two-dimensional reconstruction algorithm. The image quality is improved by the employment of an approximate correction method that uses scaling factors derived from the ratios of finite-element forward simulations in two and three spatial dimensions. The 32-channel system was employed to generate maps of the internal scattering and the absorption properties at 14 different transverse planes across the phantom. The images clearly reveal the locations of small inhomogeneous regions embedded within the phantom. These results were obtained by use of purely temporal data and without resource to reference measurements.
经过数年的研发，用于医学光学断层扫描的多通道时间分辨成像设备已完成构建。通过使用一种采用基于有限元扩散的正向模型和迭代重建求解器的方案，从时间分辨测量中重建图像。在对临床受试者进行测试之前，使用组织等效体模对全自动仪器和重建软件进行评估。我们描述了首次尝试生成一个沿轴向具有非均匀特性的体模的多层图像，同时仍使用计算速度快的二维重建算法。通过采用一种近似校正方法提高了图像质量，该方法使用从二维和三维空间中有限元正向模拟的比率导出的缩放因子。使用32通道系统在体模的14个不同横向平面上生成内部散射和吸收特性的图谱。图像清晰地揭示了体模内嵌入的小不均匀区域的位置。这些结果是通过使用纯时间数据获得的，无需参考测量。
