نتایج جستجو برای: computed tomography phantom

تعداد نتایج: 279342  

Journal: :Journal of Physics: Conference Series 2013

Background: Medical X-rays are the largest man-made source of public exposure to ionizing radiation. While the benefits of Computed Tomography (CT) are well known in accurate diagnosis, those benefits are not risk-free. CT is a device with higher patient dose in comparison with other conventional radiation procedures. Objective: This study is aimed at evaluating radiation dose to patients from ...

2017
Jun Li Wenyin Shi David Andrews Maria Werner-Wasik Bo Lu Yan Yu Adam Dicker Haisong Liu

PURPOSE The study was aimed to compare online 6 degree-of-freedom image registrations of TrueBeam cone-beam computed tomography and BrainLab ExacTrac X-ray imaging systems for intracranial radiosurgery. METHODS Phantom and patient studies were performed on a Varian TrueBeam STx linear accelerator (version 2.5), which is integrated with a BrainLab ExacTrac imaging system (version 6.1.1). The p...

Journal: :journal of biomedical physics and engineering 0
t raj verma n kumar painuly s prasad mishra s a yoganathan n singh m l b bhatt

background: the dosimetric parameters required in lung cancer radiation therapy are taken from a homogeneous water phantom; however, during treatment, the expected results are being affected because of its inhomogeneity. therefore, it becomes necessary to quantify these deviations. objective: the present study has been undertaken to find out inter- and intra- lung density variations and its dos...

2017
Kuo Men Jianrong Dai

PURPOSE To develop a projection quality-driven tube current modulation method in cone-beam computed tomography for image-guided radiotherapy based on the prior attenuation information obtained by the planning computed tomography and then evaluate its effect on a reduction in the imaging dose. MATERIALS AND METHODS The QCKV-1 phantom with different thicknesses (0-400 mm) of solid water upon it...

Journal: :Japanese Journal of Radiological Technology 1980

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 ...

Objective(s): Use of a positron emission tomography (PET)/single-photonemission computed tomography (SPECT) system facilitates the simultaneousacquisition of images with fluorine-18 fluorodeoxyglucose (18F-FDG) andtechnetium (99mTc)-tetrofosmin. However, 18F has a short half-life, and 511keV Compton-scattered photons are detected in the 99mTc energy window.Therefore, in this study, we aimed to ...

2017
Sunil Sharma Ganesh Narayanasamy Richard Clarkson Ming Chao Eduardo G. Moros Xin Zhang Yulong Yan Marjan Boerma Nava Paudel Steven Morrill Peter Corry Robert J. Griffin

PURPOSE To assess the quality of cone beam computed tomography images obtained by a robotic arm-based and image-guided small animal conformal radiation therapy device. METHOD AND MATERIALS The small animal conformal radiation therapy device is equipped with a 40 to 225 kV X-ray tube mounted on a custom made gantry, a 1024 × 1024 pixels flat panel detector (200 μm resolution), a programmable 6...

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