面向吲哚菁绿药代动力学成像的动态实验系统

Dynamic Experimental System for Indocyanine Green Pharmacokinetic Imaging

为实现小动物吲哚菁绿(ICG)药代动力学成像,设计了一套高灵敏度扩散荧光层析成像系统。该系统采用了基于离散光纤耦合光子计数采集的仿计算机断层成像扫描方式,在保障高灵敏度和大动态范围测量的前提下,可有效提高系统的空间采样分辨率;同时采用了基于光开关切换四通道串-并混和的测量模式,兼顾了测量时间分辨率和系统性价比之间的平衡。为验证实验系统的有效性,设计了可模拟小动物体内ICG代谢规律的动态仿体,并结合实验室开发的荧光剂药代动力学直接重建算法,实现了ICG代谢速率的重建。实验结果表明,该系统具有较高的空间分辨率、灵敏度和量化性。

A highly-sensitive pharmacokinetic diffuse fluorescence tomographic system is proposed to achieve the indocyanine green （ICG） pharmacokinetic imaging of small animals. The system employs a photon-counting technique based on discrete optical fiber measurement of computed tomography scanning mode in the computer tomography, which effectively improves spatial sampling resolution of the system on the premise of high sensitivity and wide dynamic measurement range. Meanwhile, it adopts serial-parallel mixed measurement mode through switching four photomuhiplier tube photon-counting channels by optical switch to obtain a balance between time resolution of measurement and cost-effectiveness of the system. We investigate the principle validity of the system by designing a dynamic phantom that can simulate ICG metabolism in living tissue. In addition, combined with the algorithm of fluorescent agent pharmacokinetic imaging developed by our laboratory, the reconstruction of ICG metabolic velocity is realized. Experimental results show that the proposed system has high sensitivity, spatial resolution and quantitativeness.