نتایج جستجو برای: solid phantom
تعداد نتایج: 206123 فیلتر نتایج به سال:
An a-Si Active Matrix Flat Panel Imager (AMFPI) prototype developed in-house has been modified to function as an in-phantom dosimetry system providing high resolution two-dimensional (2-D) data. This Active Matrix Flat Panel Dosimeter (AMFPD) system can be used as a replacement device for standard in-phantom dosimeters, such as scanning ion chambers in water, or film in solid water. The initial...
Tissue-equivalent phantoms that mimic the optical properties of human and animal tissues are commonly used in diffuse optical imaging research to characterize instrumentation or evaluate an image reconstruction method. Although many recipes have been produced for generating solid phantoms with specified absorption and transport scattering coefficients at visible and near-infrared wavelengths, t...
We report the synthesis and physical properties of a full Heusler compound, $\mathrm{Mg}{\mathrm{Pd}}_{2}\mathrm{Sb}$, which we found to show superconductivity below ${T}_{c}=2.2\phantom{\rule{0.16em}{0ex}}\mathrm{K}$. $\mathrm{Mg}{\mathrm{Pd}}_{2}\mathrm{Sb}$ was obtained by two-step solid-state reaction method its purity cubic crystal structure [$Fm\text{\ensuremath{-}}3m, a=6.4523(1)\phantom...
There is a growing interest in the use of megavoltage cone-beam computed tomography (MV CBCT) data for radiotherapy treatment planning. To calculate accurate dose distributions, knowledge of the electron density (ED) of the tissues being irradiated is required. In the case of MV CBCT, it is necessary to determine a calibration-relating CT number to ED, utilizing the photon beam produced for MV ...
We demonstrate two periodic or quasi-periodic generalizations of the Chaplygin gas (CG) type models to explain the origins of dark energy as well as dark matter by using the Weierstrass ℘(t), σ(t) and ζ(t) functions with two periods being infinite. If the universe can evolve periodically, a non-singular universe can be realized. Furthermore, we examine the cosmological evolution and nature of t...
Background: For radiotherapy of total skin including sub-cutaneous tissue up to a depth of 3 cm on the entire left leg of an adult (Angiosarcoma skin), a complex treatment with multiple stationary electron fields was planned at our clinic. The details of dosimetry, clinical dose measurements are presented. Materials and Methods: The treatment planned with 6 overlapping 9 MeV electron fields in ...
background: the heterogeneous composition of the human body presents numerous tissue types and cavities with widely differing radiologic properties. the aim of the present work was to develop a low cost homogeneous and heterogeneous phantom and the absorbed dose were measured by ionization chamber for different radiotherapy treatment techniques and compared with treatment planning system absorb...
Lens dose is a concern during the treatment of facial lesions with anterior electron beams. Lead shielding is routinely employed to reduce lens dose and minimize late complications. The purpose of this work is twofold: 1) to measure dose pro-files under large-area lead shielding at the lens depth for clinical electron energies via film dosimetry; and 2) to assess the accuracy of the Pinnacle tr...
In-vivo dosimetry techniques are currently being applied only by a few Centers because they require time-consuming implementation measurements, and workload for detector positioning and data analysis. The transit in-vivo dosimetry performed by the electronic portal imaging device (EPID) avoids the problem of solid-state detector positioning on the patient. Moreover, the dosimetric characterizat...
PURPOSE Developed herein is a three-dimensional (3D) flow contrast imaging system leveraging advancements in the extension of laser speckle contrast imaging theories to deep tissues along with our recently developed finite-element diffuse correlation tomography (DCT) reconstruction scheme. This technique, termed speckle contrast diffuse correlation tomography (scDCT), enables incorporation of c...
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