阻抗CT图像重建算法的研究

经过严密的理论推导,提出了一种阻抗CT图像重建的新方法,它利用一系列等位线将场域分割成若干相互独立的区域,通过对这些区域单独进行分析,使得Jacobi矩阵稀疏化,既大大减小了内存量,又减小了计算量。在用等参四边形有限元法作正向问题计算的基础上对方法进行了实现和初步的计算机仿真计算,并同其它方法进行了比较。在求解线性超定方程时,应用了松弛型Hildreth区间规划算法,有效地克服了稀疏后的Jacobi矩阵非零元分布的不规则性和方程的不相容性。

A STUDY ON THE IMAGE RECONSTRUCTION AIGORITHM FOR ELECTRICAL IMPEDANCE CT

A new image reconstruction method fur electrical impedance CT is derived rigorously. The Jacobi Matrix is made sparse by analysing each narrow region which is detrmined by equipotential lines seperately. Both storage and computation can be deduced. The method is realized by using first order square FEM and some computer model is reconstructed. The relaxed version of Hildreth's method for interval convex programing is applied, which can hold the sparsity of the Jacobi Matrix and overcome the ill-condition of the matrix.