基于虚拟源模型的荧光扩散断层成像算法研究

发布时间：2018-07-09 12:34

本文选题：FDOT + 正向问题　；参考：《西安科技大学》2017年硕士论文

【摘要】：荧光散射断层成像(FDOT)是光学层析扫描与荧光显影剂结合发展出的新兴三维医学成像技术,对癌症的早期诊断具有非常重要的意义。本文提出了利用平面镜反射的原理对现有常规单角度FDOT系统进行优化的方法,有效解决了现有的多角度FDOT成像系统普遍存在特异性高、不易推广、造价高等问题。FDOT分子成像技术包括正向问题和逆向问题。本文对于FDOT的正向问题,介绍了扩散近似模型以及利用有限元方法对该模型的求解。FDOT的逆向问题即是重建问题,在正向的基础上,本文采用虚拟源模型的图像重建算法,利用小波变化方程对采集信息进行数据压缩,降低了重建的时间,并引入先验信息,重建中使用正则化约束,降低重建误差。通过仿真实验,验证了该优化方法的可行性,最后分别在单角度和优化后的多角度系统上进行了多组动物对比实验,同时选择不同平面镜角度进行FDOT多角度实验,并利用TOAST++工具箱进行图像重建。仿真结果和动物实验数据表明,相较于常规单角度成像系统平面镜多角度FDOT系统重建出的肿瘤断层图像完整,能够很好地反映肿瘤的分布,重建的效果从成像时间、信噪比、误差几个方面都有所降低,提升了重建图像的清晰度和分辨率,多角度FDOT系统成象在平面镜为40°左右时成像效果最佳,这使得FDOT分子成像技术能更早的应用于肿瘤临床前研究和临床实践。
[Abstract]:Fluorescence scattering tomography (FDOT) is a new three-dimensional medical imaging technology developed by the combination of optical tomography and fluorescent developer. It is very important for early diagnosis of cancer. This paper proposes a method to optimize the existing conventional single angle FDOT system by using the principle of plane mirror reflection. The angle FDOT imaging system has high specificity and is not easy to be popularized. The.FDOT molecular imaging technology with high cost includes forward and reverse problems. This paper introduces the diffusion approximation model and the inverse problem of the solution of the.FDOT by the finite element method, which is a positive basis for the forward problem of FDOT. In this paper, the image reconstruction algorithm of virtual source model is used to compress the collection information by using the wavelet change equation, and the reconstruction time is reduced, and the prior information is introduced. The regularization constraint is used in the reconstruction and the reconstruction error is reduced. The feasibility of the optimization method is verified by the simulation experiment. Finally, the single angle and optimization are given respectively. Several groups of animal comparison experiments were carried out on the post multi angle system, and FDOT multi angle experiments were carried out with different plane mirror angles, and the image reconstruction was carried out by the TOAST++ toolbox. The simulation results and animal experiment data showed that the tumor fault images reconstructed by the multi angle FDOT system of the conventional single angle imaging system were finished. It can reflect the distribution of the tumor very well. The reconstruction effect is reduced from the imaging time, the signal to noise ratio and the error, which improves the clarity and resolution of the reconstructed image. The imaging effect of the multi angle FDOT system is best when the plane mirror is about 40 degrees, which makes the FDOT molecular imaging technology can be applied to the tumor clinic earlier. Previous research and clinical practice.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R730.44;TP391.41

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