نتایج جستجو برای: based phantom
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The accurate description of phonons in a solid is one the central research topics field condensed matter physics and materials science. Here, authors report successful application $a\phantom{\rule{0}{0ex}}b$ $i\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}o$ quantum Monte Carlo (QMC) framework to phonon dispersion calculat...
In this paper a novel anatomic-like phantom, to simulate human respiratory motion is presented. The phantom is capable to simulate thorax and abdomen motion for surface based respiratory gating systems. This phantom is used to evaluate a system based on time-of-flight (TOF) technology, to detect respiratory motion. It could be shown that the correlation between the reference motion, performed b...
Quality control in mammography is based upon subjective interpretation of the image quality of a test phantom. In order to suppress subjectivity due to the human observer, automated computer analysis of the Leeds TOR(MAM) test phantom is investigated. Texture analysis via grey-level co-occurrence matrices is used to detect structures in the test object. Scoring of the substructures in the phant...
Background: HDR brachytherapy is one of the commonest methods of nasopharyngeal cancer treatment. In this method, depending on how advanced one tumor is, 2 to 6 Gy dose as intracavitary brachytherapy is prescribed. Due to high dose rate and tumor location, accuracy evaluation of treatment planning system (TPS) is particularly important. Common methods used in TPS dosimetry are based on computat...
objective(s): the present study was conducted to examine whether the standardized uptake value (suv) may be affected by the spatial position of a lesion in the radial direction on positron emission tomography (pet) images, obtained via two methods based on time-of-flight (tof) reconstruction and point spread function (psf). methods: a cylinder phantom with the sphere (30mm diameter), located in...
Introduction Quality control is an important phenomenon in nuclear medicine imaging. A Jaszczak SPECT Phantom provides consistent performance information for any SPECT or PET system. This article describes the simulation of a Jaszczak phantom and creating an executable phantom file for comparing assessment of SPECT cameras using SIMIND Monte Carlo simulation program which is well-established fo...
Purpose: To develop and test an integrated simulation system based on the digital Extended Cardio Torso (XCAT) phantom for 4-dimensional (4D) radiation therapy of lung cancer. Methods: A computer program was developed to facilitate the characterization and implementation of the XCAT phantom for 4D radiation therapy applications. To verify that patient-specific motion trajectories are reproducib...
BACKGROUND Recommended phantom-based quality assurance measurements in B-mode ultrasound (US) may be tedious. For the purpose of cost-effective US quality assurance it is important to evaluate measurements that effectively reflect the quality of US scanner. PURPOSE To find out which recommended phantom-based quality assurance measurements are effective in detecting dead or weak transducer ele...
PURPOSE Develop a technique to fabricate a 3D anthropomorphic breast phantom with known ground truth for image quality assessment of 2D and 3D breast x-ray imaging systems. METHODS The phantom design is based on an existing computer model that can generate breast voxel phantoms of varying composition, size, and shape. The physical phantom is produced in two steps. First, the portion of the vo...
Introduction: The use of electronic portal imaging devices (EPIDs) is a method for the dosimetric verification of radiotherapy plans both pretreatment and in-vivo. The aim of this study was to test a 2D EPID-based dosimetry algorithm for dose verification of some plans inside a homogenous and anthropomorphic phantom and in-vivo, as well. Materials and Methods: </strong...
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