نتایج جستجو برای: water phantom

تعداد نتایج: 566361  

Journal: :Physics in medicine and biology 2001
M J Butson T Cheung P K Yu

Radiochromic film is investigated for use in dosimetry in water phantoms as opposed to solid phantoms. Investigations are performed to measure the penetration rates of water into radiochromic film and to assess the effects on optical density that this penetration causes. The effects of film orientation during irradiation in water are also tested. Results show that only a small penetration rate ...

Journal: :Medical physics 2013
Adam M Alessio Lawrence R MacDonald

PURPOSE To quantify the concentration of soft-tissue components of water, fat, and calcium through the decomposition of the x-ray spectral signatures in multi-energy CT images. METHODS Decomposition of dual-energy and multi-energy x-ray data into basis materials can be performed in the projection domain, image domain, or during image reconstruction. In this work, the authors present methodolo...

2012
Igor Smirnov

This article is related to the experimental data regarding the ability of MRET Noise Field Generator (MRET NFG) placed at the distance of 7 feet from “phantom head” exposed to RF phones radiation to reduce specific absorption rate (SAR) of the water based solution inside “phantom head”. The core part of Generator is MRET polymer compound. Due to the fractal geometry structure of MRET polymer co...

2015
Somayeh Asadi Mehdi Vaez‐zadeh S. Farhad Masoudi Faezeh Rahmani Courtney Knaup Ali S. Meigooni

The effects of gold nanoparticles (GNPs) in 125I brachytherapy dose enhancement on choroidal melanoma are examined using the Monte Carlo simulation technique. Usually, Monte Carlo ophthalmic brachytherapy dosimetry is performed in a water phantom. However, here, the compositions of human eye have been considered instead of water. Both human eye and water phantoms have been simulated with MCNP5 ...

Journal: :acta medica iranica 0
w.h. fry a. inst. e. majoubi a. jalali

a method is described whereby the isodose curves of a cobalt unit were measured, using a simple photographic technique. the method reduces the effects of experimental errors and artifacts by cross_plotting the constants of decrement liner. the method is self-calibrating, and affords a useful allernative to the more usual water phantom pro:edures, in cases when this apparatus is not available

2005
K Krugh J Esthappan

Purpose: A simple method for verifying the dose point kernel of Ir-192 source used in HDR brachytherapy using Kodak EDR2 film in a spiralphantom. Method and Materials: A spiral solid water phantom availablefrom Gammex International for IMRT QA was modified for this study. A CT scan image of the phantom was acquired with a 10 x 12 inch filmloaded in the spiral groove. A 3.5 mm long 8...

2016
Davide Montanari Enrica Scolari Chiara Silvestri Ernest K Osei Bryan Schaly Andre Fleck Arnold W Malcolm

Accurate knowledge of ionizing radiation dose from cone-beam CT (CBCT) imaging in radiotherapy is important to allow concomitant risks to be estimated and for justification of imaging exposures. This study uses a Monte Carlo CBCT model to calculate imaging dose for a wide range of imaging protocols for male and female patients. The Elekta XVI CBCT system was modeled using GATE and simulated dos...

Journal: :Journal of radiological protection : official journal of the Society for Radiological Protection 2017
T E Marchant K D Joshi

Accurate knowledge of ionizing radiation dose from cone-beam CT (CBCT) imaging in radiotherapy is important to allow concomitant risks to be estimated and for justification of imaging exposures. This study uses a Monte Carlo CBCT model to calculate imaging dose for a wide range of imaging protocols for male and female patients. The Elekta XVI CBCT system was modeled using GATE and simulated dos...

Journal: :Magnetic resonance in medicine 2012
Els Fieremans Antonio Pires Jens H Jensen

Dairy cream is shown to be a simple, inexpensive, isotropic phantom useful for testing diffusional kurtosis imaging data acquisition and postprocessing. The MR-visible protons of cream exhibit slow and fast diffusion components, attributed to the fat and water protons, respectively, which give rise to a diffusion coefficient of 1.1 μm(2)/ms and a diffusional kurtosis of 1.2. These parameter val...

Journal: :Reports of practical oncology and radiotherapy : journal of Greatpoland Cancer Center in Poznan and Polish Society of Radiation Oncology 2010
D Sardari R Maleki H Samavat A Esmaeeli

Radiation therapy is an established method of cancer treatment. New technologies in cancer radiotherapy need a more accurate computation of the dose delivered in the radiotherapy treatment plan. This study presents some results of a Geant4-based application for simulation of the absorbed dose distribution given by a medical linear accelerator (LINAC). The LINAC geometry is accurately described ...

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