Time-of-flight (TOF) positron emission tomography (PET) technology has recently regained popularity in clinical PET studies for improving image quality and lesion detectability. Using TOF information, the spatial location of annihilation events is confined to a number of image voxels along each line of response, thereby the cross-dependencies of image voxels are reduced, which in turns results ...

UNLABELLED The purpose of this study was to investigate the quantitative properties and effects of ordered-subset expectation maximization (OSEM) on kinetic modeling compared with filtered backprojection (FBP) in dynamic PET studies. Both phantom and patient studies were performed. METHODS For phantom studies dynamic two-dimensional emission scans with 10-min frames and 20-min scan intervals ...

introduction: ordered subset expectation maximization (osem), is an effective iterative method for spect image reconstruction. the aim of this study is the evaluation of the role of system matrix in osem image reconstruction method using four different physical beam radiation models with three detection configurations. methods: spect was done with an arc of 180 degree in 32 projections after i...

  Introduction: Ordered subset expectation maximization (OSEM), is an effective iterative method for SPECT image reconstruction. The aim of this study is the evaluation of the role of system matrix in OSEM image reconstruction method using four different physical beam radiation models with three detection configurations. Methods: SPECT was done with an arc of 180 deg...

Introduction: While the necessity of replacing voxels with blobs in conventional tomographic reconstruction based upon line-integrals is clear, it is not however well-investigated in plane- integral-based reconstruction. The problem is more challenging in convergent-plane projection reconstruction. In this work, we are aiming at utilizing blobs as alternative to voxels. <stron...

UNLABELLED The aim of this study was to compare the performance of filtered backprojection (FBP) and ordered-subset expectation maximization (OSEM) reconstruction algorithms available in several types of commercial SPECT software. METHODS Numeric simulations of SPECT acquisitions of 2 phantoms were used: the National Electrical Manufacturers Association line phantom used for the assessment of...

BACKGROUND F18-fluorodeoxyglucose positron-emission tomography (FDG-PET) reconstruction algorithms can have substantial influence on quantitative image data used, e.g., for therapy planning or monitoring in oncology. We analyzed radial activity concentration profiles of differently reconstructed FDG-PET images to determine the influence of varying signal-to-background ratios (SBRs) on the respe...

For characterization and activity distribution of radioisotopes in nuclear waste, Active and Passive Computed Tomography (A&PCT) method can be employed. During the Active CT measurements, an external gamma/X-ray source is used to determine the attenuation map of the object. With this knowledge of the attenuation map, the Passive CT measurements are then carried out to reconstruct the activity o...

The goal of this study was to determine the quantitative accuracy of our OSEM-APDI reconstruction method based on SPECT/CT imaging for Tc-99m, In-111, I-123, and I-131 isotopes. Phantom studies were performed on a SPECT/low-dose multislice CT system (Infinia-Hawkeye-4 slice, GE Healthcare) using clinical acquisition protocols. Two radioactive sources were centrally and peripherally placed insid...