Positron emission computerized tomography (PET) based on Ordered Subsets Expectation Maximization (OS-EM) is usually used to computerized tomography, which imposes the radionuclide to emission positron. But it also has some disadvantage as costing long time and bad reconstruction quality. Filtered Back Projection (FBP) that has many advantages such as simple structure and short reconstruction t...

BACKGROUND Generally, attenuation correction is made by incorporating a linear attenuation coefficient, which is based on the attenuation coefficient map (mu-map) created from a computed tomography scan, into the ordered subsets-expectation maximization reconstruction method in non-uniform domains. A non-uniform Chang's attenuation correction method that uses the mu-map created from a computed ...

We consider regularization methods of Kaczmarz type in connection with the expectation-maximization (EM) algorithm for solving ill-posed equations. For noisy data, our methods are stabilized extensions of the well established ordered-subsets expectation-maximization iteration (OS-EM). We show monotonicity properties of the methods and present a numerical experiment which indicates that the exte...

Introduction: Quantitative evaluation is recommended to improve diagnostic ability and serial assessment of dopamine transporter (DAT) density scans. We decided to compare the ordered subsets expectation-maximization (OSEM) with filtered back-projection (FBP), and to investigate the impact of different iteration and cut-off frequencies on SBR values. Methods</stro...

The authors define ordered subset processing for standard algorithms (such as expectation maximization, EM) for image restoration from projections. Ordered subsets methods group projection data into an ordered sequence of subsets (or blocks). An iteration of ordered subsets EM is defined as a single pass through all the subsets, in each subset using the current estimate to initialize applicatio...

Let m + n particles be thrown randomly, independently of each other into N cells, using the following two-stage procedure. 1. The first m particles are allocated equiprobably, that is, the probability of a particle falling into any particular cell is 1/N . Let the ith cell contain mi particles on completion. Then associate with this cell the probability ai = mi/m and withdraw the particles. 2. ...

| We deene ordered subset processing for standard algorithms (such as Expectation Maximization, EM) for image restoration from projections. Ordered subsets methods group projection data into an ordered sequence of subsets (or blocks). An iteration of ordered subsets EM is deened as a single pass through all the subsets, in each subset using the current estimate to initialise application of EM w...

In this paper, the new concept of near PS-compactness in L-topological spaces is introduced. It is defined for any L-subset. Its characterizations and topological properties are systematically studied. And the relationship is exposed between near PScompactness and PS-compactness, and also fuzzy compactness. 2003 Elsevier Inc. All rights reserved.

Autoradiography (ARG) has been used for quantitative analysis of the cerebral blood flow using 123I-IMP, and the regional cerebral blood flow (rCBF) can be assessed more accurately with scatter and attenuation correction. Currently, the filtered back projection (FBP) method is generally used for image reconstruction. However, we anticipate obtaining more accurate rCBF by the ordered ...