نتایج جستجو برای: phantom scatter factor

تعداد نتایج: 870740  

Mahsa Noori-Asl, somayeh Sotoudeh

Introduction: In nuclear medicine imaging, detection of the scattered photons along with the primary photons is one of the major problems that can lead to a decrease in ddiagnostic accuracy. Therefore, use of a suitable scatter correction method can help to improve of the image quality and increase of diagnostic accuracy. The aim of this study is evaluation of five energy wind...

Journal: :Physics in medicine and biology 2008
Kathy Willowson Dale L Bailey Clive Baldock

A method for achieving quantitative single-photon emission computed tomography (SPECT) based upon corrections derived from x-ray computed tomography (CT) data is presented. A CT-derived attenuation map is used to perform transmission-dependent scatter correction (TDSC) in conjunction with non-uniform attenuation correction. The original CT data are also utilized to correct for partial volume ef...

2013
Abraham E. Bacarra

Intestinal epithelial cells rest on a fibroblast sheath. Thus, factors produced by these fibroblasts may influence epithelial function in a paracrine fashion. We examined modulation of intestinal epithelial function by one such fibroblast product, scatter factor/ hepatocyte growth factor (HGF/SF). This effect was studied in vitro by using model T84 intestinal epithelial cells. When applied to c...

2010

ID: 14214 Title: A novel scatter reduction and correction method to improve cone-beam CT (CBCT) image quality Purpose: To develop a novel scatter reduction and correction method to improve the CBCT image quality for IGRT applications. Method and Materials: A one-dimensional grid composed of lead with equal interspacing was positioned between the x-ray source and the imaging object during CBCT a...

2015
Hiroaki Hasegawa Masanori Sato Hiroshi Tanaka David O. Carpenter

The purpose of this study was to evaluate scatter radiation dose to the subject surface during X-ray computed tomography (CT) fluoroscopy using the integrated dose ratio (IDR) of an X-ray dose profile derived from an optically stimulated luminescent (OSL) dosimeter. We aimed to obtain quantitative evidence supporting the radiation protection methods used during previous CT fluoroscopy. A multis...

Journal: :Revista Brasileira de Física Médica 2022

A proposed method to obtain the dose for Computed Tomography was evaluated on long a phantom, made of polyethylene. This phantom is 600 mm large. Adopting an empirical characterized function , tendency asymptotical grow by increase scanning length can estimate in infinite single axial rotation x-ray tube. The curve estimated different clinical protocols: tension, pitch, head/body, and center/pe...

2012
Masahiro Nakano Robin F. Hill May Whitaker Jung‐Ha Kim Zdenka Kuncic

The present study quantified surface doses on several rectangular phantom setups and on curved surface phantoms for a 6 MV photon field using the Attix parallel-plate chamber and Gafchromic EBT2 film. For the rectangular phantom setups, the surface doses on a homogenous water equivalent phantom and a water equivalent phantom with 60 mm thick lung equivalent material were measured. The measureme...

Journal: :BMC Medical Imaging 2007
Lawrence T. Dauer Kevin A. Casciotta Yusuf E. Erdi Lawrence N. Rothenberg

BACKGROUND It is estimated that 60 million computed tomography (CT) scans were performed during 2006, with approximately 11% of those performed on children age 0-15 years. Various types of gonadal shielding have been evaluated for reducing exposure to the gonads. The purpose of this study was to quantify the radiation dose reduction to the gonads and its effect on image quality when a wrap-arou...

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