Magnetic resonance-coupled fluorescence tomography scanner for molecular imaging of tissue
Magnetic resonance-coupled fluorescence tomography scanner for molecular imaging of tissue
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DOI：
10.1063/1.2919131
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发表时间：
2008-06-01
影响因子：
1.6
通讯作者：
Paulsen, Keith D.
中科院分区：
文献类型：
--
作者：
Davis, Scott C.;Pogue, Brian W.;Paulsen, Keith D.
描述了一种多通道光谱分辨光学断层扫描系统，用于从临床MRI内对小动物中的分子目标进行成像。长光源/检测器光纤以接触模式工作，并将来自磁体孔中组织表面的光耦合到16个光谱仪，每个光谱仪包含两个针对近红外波长范围优化的光栅。连接到每个光谱仪的高灵敏度、冷却的电荷耦合器件提供光谱分辨信号的检测，并且曝光时间在每个光纤处自动采集。该设计允许对反射光进行光谱拟合，从而将荧光信号与非特异性背景分离，这提高了成像低荧光团浓度时的准确度和灵敏度。利用基于光子在组织中传播的扩散近似的非线性重建方法恢复荧光产额的图像。从MR图像导出的组织形态用作引导光学重建算法的成像模板。灵敏度研究表明，吲哚菁绿色荧光产率的回收值在70 mm直径的均匀体模中与1 nM浓度呈线性关系，并且检测到接近10 pM是可行的。体模数据还证明了在临床相关尺寸的组织体积中不完美荧光团摄取的成像能力。独特的啮齿动物MR线圈提供光纤接入，用于小动物的同时光学和MR数据采集。使用原位神经胶质瘤肿瘤模型的试点小鼠研究证明了表皮生长因子受体靶向荧光探针在体内的光学-MRI成像。(c)2008年美国物理学会。
A multichannel spectrally resolved optical tomography system to image molecular targets in small animals from within a clinical MRI is described. Long source/detector fibers operate in contact mode and couple light from the tissue surface in the magnet bore to 16 spectrometers, each containing two optical gratings optimized for the near infrared wavelength range. High sensitivity, cooled charge coupled devices connected to each spectrograph provide detection of the spectrally resolved signal, with exposure times that are automated for acquisition at each fiber. The design allows spectral fitting of the remission light, thereby separating the fluorescence signal from the nonspecific background, which improves the accuracy and sensitivity when imaging low fluorophore concentrations. Images of fluorescence yield are recovered using a nonlinear reconstruction approach based on the diffusion approximation of photon propagation in tissue. The tissue morphology derived from the MR images serves as an imaging template to guide the optical reconstruction algorithm. Sensitivity studies show that recovered values of indocyanine green fluorescence yield are linear to concentrations of 1 nM in a 70 mm diameter homogeneous phantom, and detection is feasible to near 10 pM. Phantom data also demonstrate imaging capabilities of imperfect fluorophore uptake in tissue volumes of clinically relevant sizes. A unique rodent MR coil provides optical fiber access for simultaneous optical and MR data acquisition of small animals. A pilot murine study using an orthotopic glioma tumor model demonstrates optical-MRI imaging of an epidermal growth factor receptor targeted fluorescent probe in vivo. (c) 2008 American Institute of Physics.