نتایج جستجو برای: ray vrx ct

تعداد نتایج: 397790  

Introduction: The purpose of the current study was to investigate the effect of X-ray spectra on the sensitivity of a polymer gel dosimeter imaged with a conventional computed tomography (CT) scanner. Material and Methods: The whole process of CT imaging of an irradiated polymer gel was simulated by MCNPX Monte Carlo (MC) code. The imaging of polyacrylamide gel was accomplished by means of a co...

A. Karimian, A. Rahmim, M.N.  Nasrabadi, N. Ahmadi,

Background: In CT systems, the machine utilizes a bowtie filter to shape the X-ray beam and remove lower energy photons. The shape of this bowtie filter is complicated and its geometry is often not available in detail. These renders the CT dose index (CTDI) to have different values in measurement versus Monte Carlo simulation studies and other analytical calculations especially in dosimetry of ...

Journal: :Journal of X-ray science and technology 1998
P Hammersberg

Generally, computerised tomography (CT) is an X-ray based non-destructive testing method that was developed for medical purposes in the seventies and introduced for industrial applications during the eighties. CT produces maps of the X-ray linear attenuation coefficient of an object’s interior; presented either as cross section images (two-dimensional CT) or as volume information (three-dimensi...

2015
Elizabeth Lazarus Brian C. Allen Fergus V. Coakley Matthew S. Hartman Matthew T. Heller Keyanoosh Hosseinzadeh

Radiologic Procedure Rating Comments RRL* CT abdomen and pelvis without and with contrast 2 ☢ ☢ ☢ ☢ X-ray abdomen 2 ☢ ☢ CT abdomen and pelvis without contrast 2 ☢ ☢ ☢ ☢ CT abdomen and pelvis with contrast 2 ☢ ☢ ☢ ☢ X-ray contrast enema 2 ☢ ☢ ☢ X-ray cystography 2 ☢ ☢ ☢ MRI pelvis without and with contrast 2 MRI may be indicated if urethral diverticulum is suspected. O MRI pelvis without contras...

Journal: :Medical physics 2006
Jovan G Brankov Miles N Wernick Yongyi Yang Jun Li Carol Muehleman Zhong Zhong Mark A Anastasio

Conventional x-ray computed tomography (CT) produces a single volumetric image that represents the spatially variant linear x-ray attenuation coefficient of an object. However, in many situations, differences in the x-ray attenuation properties of soft tissues are very small and difficult to measure in conventional x-ray imaging. In this work, we investigate an analyzer-based imaging method, ca...

2012
Phan Tuong Huynh Sergy V. Lemeshko Mary C. Mahoney Mary S. Newell Lora D. Barke Jennifer A. Harvey Mary K. Hayes Peter M. Jokich Martha B. Mainiero Samir Bipin Patel Bruce G. Haffty

Radiologic Procedure Rating Comments RRL* Rule Out Bone Metastases Tc-99m bone scan whole body 2 ☢ ☢ ☢ X-ray radiographic survey whole body 2 ☢ ☢ ☢ FDG-PET/CT whole body 2 ☢ ☢ ☢ ☢ Rule Out Thoracic Metastases X-ray chest 2 ☢ CT chest without contrast 2 ☢ ☢ ☢ CT chest with contrast 2 ☢ ☢ ☢ CT chest without and with contrast 2 ☢ ☢ ☢ X-ray tomography chest 2 ☢ ☢ FDG-PET/CT whole body 2 ☢ ☢ ☢ ☢ Rul...

Journal: :journal of dental research, dental clinics, dental prospects 0
tahmineh razi assistant professor, department of oral and maxillofacial radiology tabriz university of medical science mahdi niknami assistant professor, department of oral and maxillofacial radiology tehran university of medical science fakhri alavi ghazani post graduate student department of oral and maxillofacial radiology tabriz university of medical science

background and aims. cone-beam computed tomography (cbct) is an imaging system which has many advantages over computed tomography (ct). in ct scan, hounsfield unit (hu) is proportional to the degree of x-ray attenuation by the tissue. in cbct, the degree of x-ray attenuation is shown by gray scale (voxel value). the aim of the present study was to investigate the relationship between gray scale...

2013
Joseph J. Lifton Andrew A. Malcolm John W. McBride

X-ray computed tomography (CT) is a non-destructive, radiographic scanning technique that enables the visualisation of both the internal geometry and the composition of a workpiece; X-ray CT is therefore well suited for non-destructive inspection tasks. Several physical processes reduce the quality of CT images, and therefore influence both qualitative and quantitative analyses made from CT dat...

2017
Ji Won Moon James Ki Shinn Dalsung Ryu Se-Yang Oh Yu Shik Shim Seung Hwan Yoon

OBJECTIVE Computed tomography (CT), rather than conventional 2-dimensional radiography, was used to scan and measure pelvic parameters. The results were compared with measurements using X-ray. METHODS Pelvic parameters were measured using both CT and X-ray in 254 patients who underwent both abdomino-pelvic CT and X-ray at the pelvic site. We assessed the similarity of the pelvic parameters be...

Journal: :Journal of the Japan Society for Composite Materials 1986

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