为了实现高灵敏度、高空间采样密度的扩散荧光层析成像，提出了一种基于光子计数技术的仿 CT 扫描模式的成像方法．光源经过准直后入射到仿体上，光电倍增管探测得到光源同一水平面101.25°～258.75°均匀分布的8路探测信号．按照与 CT 相似的方式，系统旋转仿体以实现对仿体的0°～360°扫描，采用光子计数方式采集多个光源入射角下多个探测位置的光子数信息，获得的大量数据可降低重建过程的病态性，使重建结果更加准确．仿体实验证明，对于荧光剂Cy5.5的探测可以达到2,nmol/L左右的浓度和边对边距离5,mm的空间分辨率，增加空间采样密度可以提高系统的灵敏度和分辨率．%A CT-analogous mode of diffuse fluorescence tomography(DFT)based on photon-counting has been pro-posed to achieve high sensitivity and high spatial sampling density. The incidence light on the phantom is a collimated beam and eight detection fibers placed from 101. 25°to 258.75°in the same place of the source collecting eight de-tective signals. By rotating the phantom from 0°to 360°as a CT system does,the system acquires the number of photon by photon-counting on different sites of the phantom under different incident perspectives. The large data-set reduces the ill-posed problem of the reconstruction and achieves a more accurate imaging. The proposed system can disclose the concentration of Cy5.5 target with a high sensitivity and fidelity as the concentration is above 2,nmol/L and the edge-to-edge spatial resolution is about 5,mm. By increasing the spatial sampling density,a better resolution and sensitivity can be achieved.
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