نتایج جستجو برای: pixelated collimator

تعداد نتایج: 3420  

2014
Amine Samoudi Karen Van Audenhaege Günter Vermeeren Micahel Poole Luc Martens Roel Van Holen Wout Joseph

INTEC, Ghent University/iMinds, Ghent, Belgium Combining Single Photon Emission Computed Tomography (SPECT) with Magnetic Resonance Imaging (MRI) results in an interaction of the time-varying magnetic field gradients with the highly conducting tungsten collimator, which generates a secondary magnetic field causing spatial distortions in reconstructed MR images. Accurate simulations are importan...

Journal: :EPJ Web of Conferences 2015

Parvaneh Darkhor Samira Abbaspour جلیل پیرایش اسلامیان,

Introduction: We have investigated cardiac SPECT with slant hole collimator in which the holes are slanted towards the target organ, to provide greater sensitivity over the parallel hole collimator. In addition, parallel hole collimator was used to obtain a comparison in FWHM, sensitivity, Compton and photoelectric area values in the simulations. Materials and Methods...

Journal: :Neurosurgery 2004
Cheng Yu Gabor Jozsef Michael L J Apuzzo Zbigniew Petrovich

OBJECTIVE To determine accurately the relative output factors, defined as the ratio of the nominal dose rate for a given collimator to that of the 60-mm collimator. This is particularly important for radiosurgical treatment of functional disorders, such as trigeminal neuralgia, in which a single large radiation dose is delivered to the target with a small collimator, such as the 5-mm collimator...

Journal: :Medical physics 2002
Yong Yang Lei Xing Arthur L Boyer Yixin Song Yimin Hu

Accurate determination of the head scatter factor Sc is an important issue, especially for intensity modulated radiation therapy, where the segmented fields are often very irregular and much less than the collimator jaw settings. In this work, we report an Sc calculation algorithm for symmetric, asymmetric, and irregular open fields shaped by the tertiary collimator (a multileaf collimator or b...

Journal: :Frontiers in Psychology 2016

Journal: :Journal of Instrumentation 2021

This paper presents the first determination of spatial resolution ANET Compact Neutron Collimator, obtained with a measuring campaign at LENA Mark-II TRIGA reactor in Pavia. novel collimator consists sequence collimating and absorbing channels organised chessboard-like geometry. It has scalable structure both length field view. is characterized by an elevated collimation power within limited le...

Journal: :IEEE Transactions on Nuclear Science 2017

Introduction: The position estimation in gamma detection system will have constant misplacements which can be corrected in the calibration procedure. In the pixelated crystal uniformly irradiation of detector will produce irregular shape due to position estimation errors. This image is called flood field image and is used to calibrate the position estimation. In this work we pr...

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