【作者】 杨恒；

【导师】 张继武；

【作者基本信息】 上海交通大学 ， 生物医学工程， 2010， 硕士

【摘要】 光学分子成像是医学成像领域的一个新兴分支,它可以在细胞和分子水平上检测人体新陈代谢和功能方面的疾病。因为红外光线或可见光可以穿透人体若干厘米并能够在人体表层被检测,我们在外部放置光源照射实验体,光线穿透人体到达荧光染剂位置(荧光染剂事先被注射到人体内),荧光染剂被激发,发出另一个波长的光波并在人体表面被检测到,荧光断层重建算法根据体外检测到的光波信息便能够重建出体内荧光染料的位置。为了能够精确的计算出荧光染剂的位置,数值分析方法(比如有限元)常用来求解描述光在组织内传播的偏微分方程。本文的目的就是提供一个基于荧光断层重建算法特点的三维网格优化算法,这个算法得到的网格是一个荧光断层重建算法的有效网格。算法结合了网格简化和网格细化两个过程,并根据体内器官组织的光照属性提出了相应的网格代价函数。算法结果证明了新网格较原网格(Digimouse)在质量上和密度上都有了非常大的提高,并能够应用在荧光分子断层重建算法中。更多还原

【Abstract】 Optical Molecular Imaging technique is a novel branch of medical imaging that has the potential to diagnose the metabolic and functional state of tissue at the cellular and molecular level. Light in the visible or near infrared spectrum penetrates several centimeters inside the body and can be measured on the surface. External light illuminating a body penetrates the tissues up to injected fluorescent molecules which absorb and reemit light at a different wavelength. Detection of the emitted light on the surface of the body can be coupled to a Fluorescence Tomography Reconstruction (FTR) algorithm to recover the location of fluorescent concentration inside the body. In order to precisely localize the fluorescent sources, numerical techniques (e.g. Finite Element Method) are used to solve the mathematical formulation which describes photon propagation in tissues. Specifically, we have developed a remeshing module to generate valid meshes for FEM in the application of FTR, this algorithm combines tetrahedron collapse operation with refinement operation,driven by cost functions specific to Fluorescence Tomography Reconstruction. Results show an increase of mesh quality and density on the final mesh which becomes a valid mesh for Fluorescence Tomography Reconstruction.更多还原