Time-resolved scanning system for double reflectance and transmittance fluorescence imaging of diffusive media
Time-resolved scanning system for double reflectance and transmittance fluorescence imaging of diffusive media
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DOI：
10.1063/1.2828054
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发表时间：
2008-01-01
影响因子：
1.6
通讯作者：
Cubeddu, Rinaldo
中科院分区：
文献类型：
--
作者：
Brambilla, Marco;Spinelli, Lorenzo;Cubeddu, Rinaldo
在这项工作中，我们提出了一种新颖的漫反射荧光成像系统，该系统基于用于平板几何形状样品的时间分辨双波长双反射率和透射率装置。我们描述了硬件装置，展示了其紧凑性和多功能性，并展示了在体模上初步测量的结果。我们全面评估了该系统的性能和动态范围。我们验证了它对于散射和吸收系数与生物组织相似且厚度约为2厘米的样品恢复其本体介质光学特性的能力。此外，当荧光团在体模中均匀扩散或集中在密封的内含物中时，我们评估了记录信号相对于荧光团浓度的线性度。在这两种情况下，我们再次观察到从10⁻⁸M到10⁻⁵M三个数量级上相当好的线性度。通过荧光内含物，我们还能够从空间分辨率（我们估计约为3毫米）和成像灵敏度（可与均匀背景区分的最小荧光染料量）方面评估该系统的成像能力，成像灵敏度确定为200飞摩尔。由于记录的数据是时间分辨的，我们还可以估计染料的荧光寿命并构建早期和晚期时间门控图像。最后，我们讨论了所提出系统的一些关键问题以及我们目前为使其适用于体内测量而正在进行的改进。（C）2008美国物理学会
In this work we present a novel diffuse fluorescence imaging system, based on time-resolved two-wavelength double reflectance and transmittance setup for slab geometry samples. We describe the hardware setup, showing its compactness and versatility and show the results on preliminary measurements on phantoms. We fully assessed the performances and the dynamic ranges of the system. We validated its ability of recovering the optical properties of the bulk medium, for samples with scattering and absorption coefficients similar to those of biological tissues and with thicknesses of about 2 cm. Moreover we assess the linearity of the recorded signals against the fluorophore concentration, when it is homogeneously diffused in the phantom or concentrated inside a sealed inclusion. In both cases we observe again a fairly good linearity, over three orders of magnitude, from 10(-8)M to 10(-5)M. With the fluorescent inclusion we were also able to assess the imaging capabilities of the system, in terms of spatial resolution, which we appraise in about 3 mm, and in terms of imaging sensitivity (the smallest quantity of fluorescent dye distinguishable from the homogeneous background), settled to 200 fmol. Since the recorded data are time resolved, we could also estimate the dye fluorescence lifetime and build early and late time gate images. We finally discuss some of the criticalities of the proposed system and the developments we are currently carrying on in order to adapt it for in vivo measurements. (C) 2008 American Institute of Physics.