نتایج جستجو برای: scatter dose
تعداد نتایج: 321996 فیلتر نتایج به سال:
Abstract Proton therapy treatment for lungs remains challenging as images enabling the detection of inter- and intra-fractional motion, which could be used proton dose adaptation, are not readily available. 4D computed tomography (4DCT) provides high image quality but is rarely available in-room, while in-room cone beam (4DCBCT) suffers from limitations stemming mostly scatter detection. This s...
to improve the accuracy of the activity quantification and the image quality in scintigraphy, scatter correction is a vital procedure. the aim of this study is to compare the accuracy in calculation of absorbed dose to patients following bone scan with 99m tc-marked diphosphonates ( 99m tc-mdp) by two different methods of background correction in conjugate view method. this study involved 22 pa...
STUDY DESIGN Using fresh cadavers, real-time dosimeters were used to estimate the radiation exposure dose from C-arm fluoroscopy to surgeons, medical staff, and patients during various procedures. OBJECTIVE The aim of this study was to evaluate the radiation exposure dose from C-arm fluoroscopy, which is used to generate real-time images of the human body, under a variety of conditions and in...
Objective(s): To investigate and compare quantitative accuracy of kidney absorbed dose measures made from both 2D and 3D imaging in patients receiving 177LuDOTATATE (Lutate) for treatment of neuroendocrine tumours (NETs). Methods: Patients receiving Lutate therapy underwent both whole body planar imaging and SPECT/CT imaging over the kidneys at time points 0.5, 4, 24, and 96-120 hours after inj...
(a) Using R, fit 3 binomial GLMs for these data corresponding to 3 link functions, logit, probit, and complementary log-log. Perform residual analysis for each model, using the deviance residuals. Obtain fitted values, π̂i, under each model and compare with observed proportions, yi/mi. Obtain the estimated dose-response curve under each model by evaluating π̂(x) = g(β̂1 + β̂2x) over a grid of value...
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...
The requirements for shielding a treatment vault with a Varian Clinac 2100 medical linear accelerator operated both with and without the flattening filter were assessed. Basic shielding parameters, such as primary beam tenth-value layers (TVLs), patient scatter fractions, and wall scatter fractions, were calculated using Monte Carlo simulations of 6, 10 and 18 MV beams. Relative integral target...
Conebeam x-ray CT (CBCT) is a developing imaging technique designed to provide relatively low-dose high-spatial-resolution visualization of high-contrast structures in the head and neck and other anatomic areas. This first installment in a 2-part review will address the physical principles underlying CBCT imaging as it is used in dedicated head and neck scanners. Concepts related to CBCT acquis...
BACKGROUND The aim of the study is to assess accuracy of activity quantification of 177Lu studies performed according to recommendations provided by the committee on Medical Internal Radiation Dose (MIRD) pamphlets 23 and 26. The performances of two scatter correction and three segmentation methods were compared. Additionally, the accuracy of tomographic and planar methods for determination of ...
Hepatocyte growth factor (HGF) is a pleiotropic cytokine that stimulates a wide array of cellular targets, including hepatocytes and other epithelial cells, melanocytes, endothelial and hematopoietic cells. We have cloned a different form of cDNA, with a deletion of 15 base pairs predicted to result in the loss of 5 amino acids from the first kringle domain. To investigate the biological activi...
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