The Study Of Fluorescence Molecular Tomography Based On Multipath Subspace Pursuit Method

Molecular Imaging is a multidisciplinary science and technology that combine mathematics,biochemistry,cytology,pharmacology,and medical imaging.It provides a new scheme and train of thought for early disease detection and quantitative analysis of drug efficacy.Fluorescence Molecular Tomography(FMT)is one of the most important techniques in the study of Optical Molecular Imaging.Fluorescence Molecular Tomography has been gradually applied in preclinical studies,and can obtain the results of three-dimensional reconstruction of tumor in vivo in mouse.However,due to the disadvantages of ill-posed FMT problem and large computational scale,the reconstruction is a challenging problem.Therefore,more effective robust and accurate reconstruction methods will be continuously developed to solve the FMT reconstruction problem.In this paper,aiming at the specific standard requirements for reconstruction accuracy,time consuming and robustness of FMT problem,a study of Fluorescence Molecular Tomography using L1 regularized sparse constraint factor is designed.Then we evaluate and judge whether the performance of the reconstruction meets the requirements of the actual reconstruction question of FMT from the aspects of reconstruction precision,reconstruction time consuming and reconstruction robustness.The main contributions of this paper are as follows.A multipath subspace pursuit method is proposed to solve the FMT problem.This method considers the problem based on the regularization of the L1 norm as a basic pursuit problem.Input requires a sparsity factor,which is usually preset based on empirical values.Then we extend the support set of different support sets by the principle of binary coding.Finally,after the iterations are stopped,the residuals of the reconstruction results resulting from each support set are evaluated.Selecting an optimal support set for FMT reconstruction.In addition,in the process of reconstruction iteration,this method inherits the backtracking and subspace projection techniques of subspace tracing method,in order to makes the reconstruction of FMT easier.To verify the applicability of the proposed reconstruction method,the simulated experiment of triple fluorescent sources and quantitative analyses of position error and relative intensity error for the experiment have been conducted.The MSP method obtains satisfactory results,and the source position error is below 1mm.Moreover,the MSP method not only can obtain the result of robustness but also can reduce the artifacts in the background.The above results revealed the MSP method for the potential FMT application.