نتایج جستجو برای: Phantom CT CT number

تعداد نتایج: 1305532  

Introduction: One of the most valuable goals of phantoms, replacing with human goals in the field of research and quality control of diagnostic X-ray systems. There are various algorithms and methods for obtaining Homogeneity and CT number linearity for CT scan device. One of the most famous of these methods, the method is to use a uniform and homogeneous environment to comput...

Introduction: One of the main steps in the optimization process in diagnostic imaging is the quality control of radiology devices. The usual method of CT scan calibration is used of a phantom. The phantom created a certain weakening for the radiation through which it passes. One of the most suitable methods for quantitative analysis of the resolution and contrast in CT scan im...

Journal: :iranian journal of radiology 0
lukas lambert department of radiology, first faculty of medicine, charles university in prague, prague, czech republic; department of radiology, general university hospital in prague, u nemocnice 2, 128 08 prague 2, czech republic. tel: +420-224962232, fax: +420-224963048 alena lambertova department of radiology, first faculty of medicine, charles university in prague, prague, czech republic; department of psychiatry, first faculty of medicine, charles university in prague, prague, czech republic jan danes department of radiology, first faculty of medicine, charles university in prague, prague, czech republic gabriela grusova fourth department of internal medicine, first faculty of medicine, charles university in prague, prague, czech republic

conclusion we constructed and validated a ct colonography phantom with correct density allowing performance of reproducible experiments. materials and methods we found 15 different phantom designs by literature search and compared their advantages and disadvantages based on their description and images. we tested various materials for density and mechanical properties and constructed a phantom ...

Ghazale Geraily, Heydar Toolee Shaghayegh Fahimi Monzari

Introduction: Total Skin Electron Therapy (TSET) and Total Body Irradiation (TBI) are kinds of treatment which use electron and photon beams to treat special types of cancers. The aim of these techniques are to deliver uniform dose to the entire skin while minimizing delivered dose to organs at risk. To check the homogeneity of dose delivery in TBI and TSET, using a humanoid ph...

Journal: :asia oceania journal of nuclear medicine and biology 0
nobuhiro yada department of radiology, shimane university hospital, izumo, japan hideo onishi biological systems sciences program, graduate school of comprehensive scientific research, prefectural university of hiroshima, hiroshima, japan

objective: in this study, we aimed to validate the accuracy of computed tomography-based attenuation correction (ctac) using the bilinear scaling method.methods: the measured attenuation coefficient (μm) was compared to a theoretical attenuation coefficient (μt ) using four different ct scanners and an rmi 467 phantom. the effective energy of the ct beam x-rays was calculated, using the aluminu...

Mohamad Yousefi Sooteh Nader Riahi Alam Sadegh Shurche

Introduction: The use of a simple tissue analog material in the fabrication of medical computed tomography (CT) imaging phantoms has great potential to help researchers. The purpose of the present study is to develop new gel tissue-equivalent materials and determine whether their CT numbers and relative electron densities vary in CT images obtained by scans at different energie...

Introduction: In radiotherapy treatment planning system (TPS), basic input is the data from computed tomography (CT) scan, which takes into account the effect of inhomogeneities in dose calculations. Measurement of CT numbers may be affected by scanner-specific parameters. Therefore, it is important to verify the effect of different CT scanning protocols on Hounsfield unit (HU) and its impact o...

Objective: In this study, we aimed to validate the accuracy of computed tomography-based attenuation correction (CTAC) using the bilinear scaling method.Methods: The measured attenuation coefficient (μm) was compared to a theoretical attenuation coefficient (μt ) using four different CT scanners and an RMI 467 phantom. The effective energy of the CT beam X-rays was calculated, using the aluminu...

2017
George Noid An Tai Guang-Pei Chen Jared Robbins X. Allen Li

Purpose Four-dimensional computed tomography (CT) images are typically used to quantify the necessary internal target volumes for thoracic and abdominal tumors. However, 4-dimensional CT is typically associated with excessive imaging dose to patients and the situation is exacerbated when using repeat 4-dimensional CT imaging on a weekly or daily basis throughout fractionated therapy. The aim of...

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