The Radon Transform for Terahertz Computed Tomography Incorporating the Beam Shape

In this paper, we study the influence of the beam shape of Terahertz (THz) radiation on the image formation in THz computed tomography and how to account for it in the reconstruction process. This is accomplished by first considering the beam shape in the forward projection using a modified Radon transform and then inverting this transform to construct new inversion techniques. Simulation experiments show that, compared to conventional back projection, directly incorporating the beam shape in the Radon transform can significantly improve image quality in terms of the mean squared error and the Structural Similarity Index.