نتایج جستجو برای: bremsstrahlung spect
تعداد نتایج: 13213 فیلتر نتایج به سال:
BACKGROUND A novel technology has been developed for ultrafast (UF) single-photon emission CT (SPECT) myocardial perfusion imaging by using a pinhole collimation design and multiple cadmium zinc telluride crystal arrays. The purpose of this study was to compare myocardial perfusion imaging obtained by UF-SPECT with standard (S) SPECT in patients with known or suspected coronary artery disease. ...
Quantitative evaluation of brain MRI/SPECT fusion methods for normal and in particular pathological datasets is difficult, due to the frequent lack of relevant ground truth. We propose a methodology to generate MRI and SPECT datasets dedicated to the evaluation of MRI/SPECT fusion methods and illustrate the method when dealing with ictal SPECT. The method consists in generating normal or pathol...
PURPOSE The purpose of this study was to compare the diagnostic performance of SPECT/CT and MRI in patients with ankle and foot pain, with regard to the lesion types. MATERIALS AND METHODS Fifty consecutive patients with ankle and foot pain, who underwent 99mTc-MDP SPECT/CT and MRI, were retrospectively enrolled in this study. Symptomatic lesions were determined based on clinical examination ...
Background: As bremsstrahlung photon beam fluence is important parameter to be known in a photonuclear reaction experiment as the number of produced particle is strongly depends on photon fluence. Materials and Methods: Photon production yield from different thickness of aluminum target has been estimated using artificial neural network (ANN) model. Target thickness and incoming electr...
Neutrino-pair bremsstrahlung by relativistic degenerate electrons in a neutron-star crust at densities 109 g cm −3 <∼ ρ <∼ 1.5 × 1014 g cm−3 is analyzed. The processes taken into account are neutrino emission due to Coulomb scattering of electrons by atomic nuclei in a Coulomb liquid, and electronphonon scattering (the phonon contribution) and Bragg diffraction (the static-lattice contribution)...
This paper presents the first study that uses the GEometry ANd Tracking 4 (GEANT4) toolkit to do quantitative comparisons with other modeling results related to the production of terrestrial gamma ray flashes and high-energy particle emission from thunderstorms. We will study the relativistic runaway electron avalanche (RREA) and the relativistic feedback process, as well as the production of b...
Introduction: Although PET scanning using F-18[FDG] is considered the superior radiotracer for tumnor imaging, Gallium-67 is still in use for some malignancies such as lymphoma and hepatoma. One of the strategies to improve the diagnostic accuracy of Gallium is to perform SPECT which is reported to be more sensitive compared to planar imaging. In this study we compa...
Introduction: Many patients have only diastolic dysfunction without any abnormality in systolic function. We compared cardiac diastolic parameters obtained by gated myocardial perfusion SPECT (Gated SPECT) with those evaluated by echocardiography. Methods: Forty-nine patients (aged 37-85 years, 19 males and 30 women) underwent Gated SPECT and echocardiogr...
There has been an increased interest in 165Dy radiossynovectomy, which emits relatively high-energy (> 1 MeV) beta rays. The production of in vivo bremsstrachlung radiation hazards warrants evaluation. The bremsstrahlung component of the decay scheme of 165Dy has been traditionally ignored in internal dosimetry calculations. We have estimated the bremsstrahlung dose of 165Dy distributed in musc...
Abstract. We report the results of extracting the hard X-ray continuum spectrum of Cas A SNR from RXTE/PCA Target of Opportunity (TOO) observations and CGRO/OSSE observations. The data can rule out the single thermal bremsstrahlung model for Cas A continuum between 2 and 150 keV. The single power law model gives a mediocre fit (∼5%) to the data with a power-law index, Γ = 2.94±0.02. A model wit...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید