Research Of Photoacoustic Imaging Algorithm Based On The Finite Element Method

Photoacoustic imaging in medical imaging is a new type of imaging technology,which has been widely concerned in recent years. Photoacoustic imaging algorithmincludes two aspects：the forward problem and the reconstruction problem. Forwardproblem refers to solving the tissue photoacoustic pressure signal with the knowndistribution of light absorption, tissue optical parameters and anatomical structure; thereconstruction problem is to solve the distribution of light absorption with the knownsurface light sound pressure distribution, tissue optical parameters and the anatomicalstructure of the situation.This article studies the photoacoustic imaging from the following two aspects:First, this article deduces the photoacoustic wave equation from the photoacousticsignals generating background and mathematical principles. In photoacoustic imagingof forward problem, based on the study of Green function method and the k-spacemethod of the forward problem of solving methods. Through simulation results and thecorresponding method, the simulated photoacoustic pressure signal is constructed. Thenbased on the physical properties of photoacoustic pressure signal, the application ofphotoacoustic imaging theory is studied.Second, this article analyses the window of filter function from practice problems,studies three kinds of filter functions based on the filtered back projectionreconstruction algorithm theory. At different frequencies and different external noise,the influence of Hanning filter function on the reconstructed image’quality is throughtlyanalysed.Finally, we do research on solution of the photoacoustic imaging’ reconstructionalgorithm and forward problem algorithm. In the numerical solution of the forwardproblem, the analysis of the two boundary conditions, and characteristics of biologicaltissue using more in line with the boundary of the forward algorithm; in photoacousticreconstruction, the study based on regularization and dual grid of reconstruction strategy,simulation experiments verify the effectiveness of the proposed algorithm.