Towards pH-sensitive imaging of small animals with photon-counting difference diffuse fluorescence tomography
Towards pH-sensitive imaging of small animals with photon-counting difference diffuse fluorescence tomography
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DOI：
10.1117/1.jbo.17.9.096011
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发表时间：
2012-09
影响因子：
3.5
通讯作者：
Jiao Li;Xin Wang;Xi Yi;Limin Zhang;Zhong-xing Zhou;Huijuan Zhao;F. Gao
中科院分区：
文献类型：
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作者：
Jiao Li;Xin Wang;Xi Yi;Limin Zhang;Zhong-xing Zhou;Huijuan Zhao;F. Gao
抽象的。细胞pH值在研究细胞活性、病理特征和药物代谢等方面的重要性已经被清楚地显示出来。在活体内监测活细胞的pH值变化，并对pH值异常的区域进行成像，可以为癌症等疾病的细胞生物学、药代动力学、诊断和治疗等研究提供宝贵的生理和病理信息。自然，块状组织的pH敏感荧光成像在近红外漫反射荧光成像(DFT)领域引起了极大的关注。本文基于专门设计的计算机断层成像-类光子计数系统和Born归一化差分图像重建方案，研究了利用连续波差分密度泛函技术定量测量混浊介质中pH诱导的荧光变化的可行性。我们在一个小动物大小的体模上进行了二维成像实验，嵌入了不同pH值的包裹体，验证了该方法的有效性。结果表明，该方法能够准确地定位目标，并对荧光产率的pH敏感变化具有定量的分辨率，为荧光寿命成像之外的pH敏感荧光成像提供了一种有前途的替代方法。
Abstract. The importance of cellular pH has been shown clearly in the study of cell activity, pathological feature, and drug metabolism. Monitoring pH changes of living cells and imaging the regions with abnormal pH-values, in vivo, could provide invaluable physiological and pathological information for the research of the cell biology, pharmacokinetics, diagnostics, and therapeutics of certain diseases such as cancer. Naturally, pH-sensitive fluorescence imaging of bulk tissues has been attracting great attentions from the realm of near infrared diffuse fluorescence tomography (DFT). Herein, the feasibility of quantifying pH-induced fluorescence changes in turbid medium is investigated using a continuous-wave difference-DFT technique that is based on the specifically designed computed tomography-analogous photon counting system and the Born normalized difference image reconstruction scheme. We have validated the methodology using two-dimensional imaging experiments on a small-animal-sized phantom, embedding an inclusion with varying pH-values. The results show that the proposed approach can accurately localize the target with a quantitative resolution to pH-sensitive variation of the fluorescent yield, and might provide a promising alternative method of pH-sensitive fluorescence imaging in addition to the fluorescence-lifetime imaging.