We propose a direct nonlinear reconstruction algorithm for Computed Tomography (CT), designed to handle low-dose measurements. It involves the filtered back-projection and adaptive nonlinear filtering in both the projection and the image domains. The filter is an extension of the learned shrinkage method by Hel-Or and Shaked to the case of indirect observations. The shrinkage functions are lear...

To realize three-dimensional (3D) optical imaging of the internal structure of an animal body, we have developed a new technique to reconstruct optical computed tomography (optical CT) images from two-dimensional (2D) transillumination images. In transillumination imaging of an animal body using near-infrared light, the image is blurred because of the strong scattering in the tissue. To overcom...

Medical imaging theory for x-ray CT and PET is based on image reconstruction from projections. In this paper a novel vector entropy imaging theory under the framework of multiple criteria decision making is presented. We also study the most frequently used image reconstruction methods, namely, least square, maximum entropy, and filtered back-projection methods under the framework, of the single...

As has already been shown with 2D-models DIRECTT (Direct iterative reconstruction of computed tomography trajectories) exceeds the spatial resolution of the classical filtered back projection. In this work the DIRECTT algorithm is extended towards cone-beam projection including iterative 3D reconstruction. The improved speed is still overcompensated by the large amount of reconstruction space a...

This paper extends particle aggregate reconstruction technique (PART), a reconstruction algorithm for binary tomography based on the movement of particles. PART supposes that pixel values are particles, and that particles diffuse through the image, staying together in regions of uniform pixel value known as aggregates. In this work, a variation of this algorithm is proposed and a focus is place...

We provide a methodology for specifying a set of simultaneous (1 CY)% confidence intervals on the intensity of each image pixel for emission and transmission tomography. These intervals give a (1 a)% confidence region which, given a specific family of noise distributions, e.g. Gaussian or Poisson, is guaranteed to contain the actual image with probability at least 1 -a. This region is a "set es...

1 Introduction Filtered Back-Projection (FBP) is a well-known algorithm for reconstruction of tomographic images from projections [1-3]. Some of FBP's highlights are: (i) allows agile software implementations , and; (ii) production of images of good quality, i. e., relatively free of artifacts. Our goal is to reconstruct images from fan beam projections collected by detectors set in a linear ar...