时域非接触型空间光扫描近红外光学层析成像系统研究

发布时间：2018-04-24 02:23

本文选题：荧光层析成像 + 非接触　；参考：《天津大学》2012年硕士论文

【摘要】：相对于目前临床应用的乳腺影像方法,漫射光层析成像(Diffuse Optical Tomography, DOT)因其良好的特异性以及实时、安全性而成为有潜力的乳腺影像新技术。在此基础上发展起来的荧光层析成像(Fluorescence Diffuse Optical Tomography,FDOT)采用吲哚菁绿(Indocyanine green, ICG)作为荧光增强剂,可使图像对比度比DOT高2-4倍。FDOT不仅可采用产率作为重建参数,也可通过同时重建荧光寿命为癌症的早期诊断提供组织体功能信息,从而提高乳腺癌早期诊断的准确率。光学成像中的传统探测模式采用光纤与成像仓直接接触进行测量。这种接触测量方式限制了数据规模和空间分辨率的提高,调节过程繁琐、耗时,并且在光纤匹配以及调整中易出现误差。为解决以上问题,本组以现有的单通道基于时间相关单光子计数(Time-Correlated Single Photon Counting Techniques, TCSPC)的时间分辨测量系统为基础,搭建了适于在体乳房成像的时域非接触式空间光扫描系统,相对于传统测量方法本方案可增大空间采样量、减小测量误差,提高空间分辨率。为实现系统的连续扫描及集成控制,利用集成了Qt插件的Visual Studio 2008平台进行了集成控制软件开发,实现了连续测量扫描以及测量曲线的实时显示等功能。利用仿体实验对所搭建系统进行了验证。在DOT实验中,利用该系统对目标仿体中异质体的吸收与约化散射系数进行了成像。在FDOT实验中,分别对单目标体和双目标体进行成像。基于本组已发展的DOT和FDOT图像重建算法进行了图像重建,结果表明: DOT实验中光学参数重建值与实际值基本相符,重建目标与真实目标位置大小相符;FDOT单目标体实验中对荧光目标的产率与寿命进行重建;通过荧光产率的重建可有效对中心距为20mm、边距为15mm的目标体进行分辨进行分辨且能够实现不同浓度的双目标体相对定量重建。实验结果证明了该系统重建组织体光学参数以及进行荧光层析成像的可行性,进一步发展可推动应用于乳腺癌检测的光学层析技术发展。
[Abstract]:Compared with the current clinical breast imaging methods, Diffuse Optical Tomography (DOT) has become a potential new mammography technology due to its good specificity, real-time and safety. Based on this, fluorescence Diffuse Optical TomographyFDOT, which uses indocyanine green (ICG) as fluorescence intensifier, can make image contrast 2-4 times higher than DOT. FDOT can not only use yield as reconstruction parameter. It can also improve the accuracy of early diagnosis of breast cancer by simultaneously rebuilding fluorescence lifetime to provide tissue and body function information for early diagnosis of cancer. The traditional detection mode in optical imaging is measured by direct contact between optical fiber and imaging bin. This method of contact measurement limits the improvement of data scale and spatial resolution, and the adjustment process is tedious and time-consuming, and errors are easy to occur in the optical fiber matching and adjustment. In order to solve the above problems, based on the existing time-related Single Photon Counting technique (TCSPC-based) time-resolved measurement system based on time-dependent single-photon counting, a time-domain contactless spatial light scanning system suitable for in vivo mammography was built. Compared with the traditional measurement method, this scheme can increase the spatial sampling amount, reduce the measurement error and improve the spatial resolution. In order to realize the continuous scanning and integrated control of the system, the integrated control software is developed on the platform of Visual Studio 2008 which integrates QT plug-in. The functions of continuous measurement scan and real-time display of measuring curve are realized. The system is verified by body-imitating experiment. In the DOT experiment, the absorption and reduced scattering coefficients of the heterogeneity in the target are imaged by the system. In the FDOT experiment, the single object and the double object are respectively imaged. Based on the developed DOT and FDOT image reconstruction algorithms, the results show that the reconstruction values of the optical parameters in the DOT experiment are in good agreement with the actual values. The yield and lifetime of fluorescent target were reconstructed by FDOT single object experiment. The reconstruction of fluorescence yield can effectively resolve the target with central distance of 20mm and edge distance of 15mm, and can realize the relative quantitative reconstruction of different concentrations of double objects. The experimental results show that the system is feasible to reconstruct the optical parameters of tissue bodies and to perform fluorescence tomography. The further development of optical tomography technology for breast cancer detection can be promoted.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R318.51

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