نتایج جستجو برای: simind simulation

تعداد نتایج: 559017  

Journal: :iranian journal of medical physics 0
mohammad taghi bahreyni toossi medical physics research center, medical physics department, mashhad university of medical sciences, mashhad, iran

introduction spect projections are contaminated by scatter radiation, resulting in reduced image contrast and quantitative errors. backscatter constitutes a major part of the scatter contamination in lower energy windows. the current study is an evaluation of the effect of backscatter material on fwhm and image quality investigated by monte carlo simulation. materials and methods simind program...

Journal: :iranian journal of nuclear medicine 0
alireza sadremomtaz department of physics, faculty of science, university of guilan, rasht, iran zeinab telikani department of physics, faculty of science, university of guilan, rasht, iran

introduction: image quality and accuracy of in vivo activity quantification in spect are affected by collimator penetration and scatter components, especially in high energy imaging. these phenomena highly depend on the collimator characteristic and photon energy. the presence of penetrated and scattered photons from collimator in spect images degrades spatial resolution, contrast and image qua...

Jalil Pirayesh Islamian Mahdi Momennezhad Mohammad Taghi Bahreyni Toossi, Ramin Sadeghi Seyyed Rasool Zakavi

Introduction SPECT projections are contaminated by scatter radiation, resulting in reduced image contrast and quantitative errors. Backscatter constitutes a major part of the scatter contamination in lower energy windows. The current study is an evaluation of the effect of backscatter material on FWHM and image quality investigated by Monte Carlo simulation. Materials and Methods SIMIND program...

2005
ANNE LARSSON

2 Cover illustration: The logarithm of a 123 I point spread function. The point source was simulated at 14.0 cm distance from the collimator in air, with the SIMIND version described in Paper V, using parameters corresponding to a GE Millennium MPR with 2.3 × 2.3 m 2 field of view. The grey scale is processed. To Björn, family and friends If you don't care where you are, you ain't lost. ABSTRAC...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعت آب و برق (شهید عباسپور) - دانشکده مهندسی برق و کامپیوتر 1392

abstract according to increase in electricity consumption in one hand and power systemsreliability importance in another , fault location detection techniqueshave beenrecentlytaken to consideration. an algorithm based on collected data from both transmission line endsproposed in this thesis. in order to reducecapacitance effects of transmission line, distributed parametersof transmission line...

Nazila Shahmari Payvand Taherparvar

Introduction: Treatment efficacy of radiation therapy using Yttrium-90 radionuclide is evaluated by the bremsstrahlung SPECT imaging following radiation therapy. The radioisotopic images have the ability to provide reliable activity map of 90Y distribution. But these images have a low quantitative accuracy in the 90Y bremsstrahlung SPECT imaging, therefore the optimization of...

Journal: :iranian journal of medical physics 0
farshid babapour mofrad ph.d., candidate, faculty of engineering, science and research branch, islamic azad university, tehran, iran ali abbaspour tehrani-fard assistant professor, faculty of engineering, science and research branch, islamic azad university, tehran, iran babak ebrahimi m.sc., faculty of engineering, science and research branch, islamic azad university, tehran, iran dariush sardari assistant professor, faculty of engineering, science and research branch, islamic azad university, tehran, iran

introduction: spect is a diagnostic imaging technique the main disadvantage of which is the existence of poisson noise. so far, different methods have been used by scientists to improve spect images. the wavelet transform is a new method for de-noising which is widely used for noise reduction and quality enhancement of images. the purpose of this paper is evaluation of noise reduction in spect ...

Journal: :Frontiers in Physics 2023

Single-photon emission computed tomography (SPECT) is a widely used diagnostic tool, but radioactive radiation during imaging poses potential health risks to subjects. Accurate low-dose single-photon reconstruction crucial in clinical applications of tomography. However, it remains challenging problem due the high noise and low spatial resolution reconstructed images. The aim study develop deep...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان 1390

a one dimensional dynamic model for a riser reactor in a fluidized bed catalytic cracking unit (fccu) for gasoil feed has been developed in two distinct conditions, one for industrial fccu and another for fccu using various frequencies of microwave energy spaced at the height of the riser reactor (fccu-mw). in addition, in order to increase the accuracy of component and bulk diffusion, instanta...

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