UNLABELLED The Inveon dedicated PET (DPET) scanner is the latest generation of preclinical PET systems devoted to high-resolution and high-sensitivity murine model imaging. In this study, we report on its performance based on the National Electrical Manufacturers Association (NEMA) NU-4 standards. METHODS The Inveon DPET consists of 64 lutetium oxyorthosilicate block detectors arranged in 4 c...

Quantitative analysis of bone composition is necessary for the accurate diagnosis and monitoring of metabolic bone diseases. Accurate assessment of the bone mineralization state is the first requirement for a comprehensive analysis. In diagnostic imaging, x-ray coherent scatter depends upon the molecular structure of tissues. Coherent-scatter computed tomography (CSCT) exploits this feature to ...

UNLABELLED Attenuation, photon scatter, and distance-dependent collimator-detector response are major degrading factors in myocardial SPECT images. The current study investigated whether compensation for these factors improves perfusion defect detectability, and compared the results for human observers with a previous study using a mathematical observer. METHODS Four methods were investigated...

Based on Kunyansky’s and our previous work, an efficient, analytical solution to the reconstruction problem of myocardial perfusion SPECT has been developed that allows simultaneous compensation for non-uniform attenuation, scatter, and system-dependent resolution variation, as well as suppression of signal-dependent Poisson noise. To avoid reconstructed images being corrupted by the presence o...

Scatter factor, a stimulant of epithelial cell motility, and Hepatocyte Growth Factor (HGF) were compared by cross-biological studies using naturally occurring and recombinant proteins in four bioassays. Both scatter factor and HGF produced similar effects in cell motility and DNA synthesis assays. Antibodies to scatter factor or HGF neutralized the biological activities of each cytokine, and i...

PURPOSE An attenuation correction is necessary to improve quantitative SPECT evaluation. The aim of this study was to evaluate the performance of several different types of commercial attenuation correction algorithms. METHODS We investigated the performance of four attenuation correction algorithms using a simulation phantom with and without scatter. The attenuation correction was performed ...

The aim of the study was to design and construct an anatomical and radiological phantom of a neonatal chest for investigating image quality and patient entrance surface dose (ESD). The density, elemental composition, scatter, attenuation, and absorption characteristics of different possible substitute materials were compared to that of neonatal tissues for radiological equivalence. Availability...

ABSTRACTBackground: as fluoroscopy or different angiographies are usually evaluated using TL dosimeter. Thismethod is a time-consuming procedure therefore, radiologists are usually worried and unawareof their exact radiation dose received during each fluoroscopy or angiography. In this study, anew trend for quick estimation of effective dose based on measuring air-absorbed dose of thescattered ...

We have begun clinical trials of optical tomography of the neonatal brain. To validate this research, we have built and imaged an anatomically realistic, tissue-equivalent neonatal head phantom that is hollow, allowing contrasting objects to be placed inside it. Images were reconstructed by use of two finite-element meshes, one generated from a computed tomography image of the phantom and the o...

Introduction: Gamma Knife is an instrument specially designed for treating brain disorders. In Gamma Knife, there are 201 narrow beams of cobalt-60 sources that intersect at an isocenter point to treat brain tumors. The tumor is placed at the isocenter and is treated by the emitted gamma rays. Therefore, there is a high dose at this point and a low dose is delivered to the normal tissue surroun...