We give a detailed study of the semiconvergence behavior of projected nonstationary simultaneous iterative reconstruction technique (SIRT) algorithms, including the projected Landweber algorithm. We also consider the use of a relaxation parameter strategy, proposed recently for the standard algorithms, for controlling the semiconvergence of the projected algorithms. We demonstrate the semiconve...

SUMMARY Tomo3D implements a multithreaded vectorized approach to tomographic reconstruction that takes full advantage of the computer power in modern multicore computers. Full resolution tomograms are generated at high speed on standard computers with no special system requirements. Tomo3D has the most common reconstruction methods implemented, namely weighted Back-projection (WBP) and simultan...

Simultaneous algebraic reconstruction technique (SART) [1, 2] is an iterative method for solving inverse problems of form Ax(+n) = b. This type of problems arises for example in computed tomography reconstruction, in which case A is obtained from discrete Radon transform. In this paper, we provide several methods for derivation of SART and connections between SART and other methods. Using these...

objective(s): in spect, the sinogram contains scatter and lack of attenuated counts that degrade the reconstructed image quality and quantity. many techniques for attenuation and scatter correction have been proposed. an acceptable method of correction is to incorporate effects into an iterative statistical reconstruction. here, we propose new maximum likelihood expectation maximization (mlem) ...

BACKGROUND In computed tomography (CT), there is increasing concern for potential CT radiation hazards. Several raw-data-based iterative reconstruction techniques attempt to facilitate low-dose imaging without compromising image quality, which raises the question whether these techniques may allow further dose reduction. PURPOSE To compare image quality of iterative reconstruction and filtere...

Department of Applied Physics, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA 91125, USA Department of Microbiology, Immunology & Molecular Genetics and The California NanoSystems Institute, 615 Charles E. Young Dr. S, BSRB 237; University of California Los Angeles, Los Angeles, CA 90095-7364, USA Division of Biology, California Institute of Technology, 1200 E. C...

Measurements in nanoscopic imaging suffer from blurring effects concerning different point spread functions (PSF). Some apparatus even have PSFs that are locally dependent on phase shifts. Additionally, raw data are affected by Poisson noise resulting from laser sampling and "photon counts" in fluorescence microscopy. In these applications standard reconstruction methods (EM, filtered backproje...