Finite Element Modeling for Fluorescence Molecular Tomography

Abstract

Non-contact Fluorescence Molecular Tomography (FMT) and Bioluminescence Tomography (BLT) has attracted more and more attention due to its unique advantages. For real experiments, how to obtain the 3D model of an object and the surface fluorescence distribution is one of the main obstacles. In this paper, an effective method to obtain the Finite Element Model is presented. We discuss the geometric and mathematical principles in detail. We prove that the FEM model generated by the method has enough quality for reconstruction. We demonstrate the quality of the model through a series of examples. This method can realize the whole process only by using a single-mode optical system. Firstly, a series of white light and fluorescence images are collected along the object in white light flat field illumination mode and excitation fluorescence mode respectively. The white light illumination images are used to reconstruct the 3D model contour of the object. After voxelization with appropriate resolution, we use the Delaunay algorithm to divide the model into tetrahedral finite elements. For the fluorescence image, we proposed a method based on vertex normal vector to realize the photon flux density mapping from 2D fluorescence image to 3D Finite Element Method (FEM) mesh nodes of the surface. The experimental results prove the accuracy of the model and the mapping, and the FEM obtained can meet the needs of FMT/ BLT reconstruction.