نتایج جستجو برای: collimator detector response

تعداد نتایج: 1033857  

Jamal Amiri

Introduction: The Monte Carlo simulation is used to enhance reliability in the experiments related to nuclear instruments. in addition, that is used to calculate the different components of the neutron and gamma ray fluxes in boron neutron capture therapy(BNCT) and neutron capture (NCT)applications. BNCT is one of the methods in radiotherapy, that is used the neutron beam for ki...

2008
André Sopczak

The importance of collimator R&D with test beam facilities is demonstrated with the example of ILC collimator studies at SLAC End Station A. Related LHC collimator aspects and longer term plans are addressed. Presented at IDTB07, ILC Detector Test Beam workshop, Fermilab, USA, 2007.

Introduction:It is well-recognized that collimator-detector response (CDR) is the main image blurring factor in SPECT.  In this research, we compensated the images for CDR in molecular SPECT by using STIR reconstruction framework. Methods: To assess resolution recovery capability of the STIR, a phantom containing five point sources along with a micro Derenzo p...

Journal: :Medical physics 2004
Gengsheng L Zeng Daniel Gagnon

This paper discusses the use of small pixels in a spinning CdZnTe single photon emission computed tomography (SPECT) camera that is mounted with a parallel slat collimator. In a conventional slat collimation configuration, there is a detector pixel between two adjacent collimator slats. In our design, the pixel size is halved. That is, there are two smaller pixels to replace a regular pixel bet...

Alireza Sadremomtaz, Zeinab Telikani

Introduction: Image quality and accuracy of in vivo activity quantification in SPECT are affected by collimator penetration and scatter components, especially in high energy imaging. These phenomena highly depend on the collimator characteristic and photon energy. The presence of penetrated and scattered photons from collimator in SPECT images degrades spatial resolution, contr...

Journal: :Physics in medicine and biology 2015
N Ploquin G Kertzscher E Vandervoort J E Cygler C E Andersen P Francescon

A dosimetry system based on Al2O3:C radioluminescence (RL), and RADPOS, a novel 4D dosimetry system using microMOSFETs, were used to measure total scatter factors, (S(c,p))(f(clin))(det), for the CyberKnife robotic radiosugery system. New Monte Carlo calculated correction factors are presented and applied for the RL detector response for the 5, 7.5 and 10 mm collimators in order to correct for ...

Journal: :Physics in medicine and biology 1994
J Ye Z Liang D P Harrington

An efficient reconstruction method for myocardial perfusion single-photon emission computed tomography (SPECT) has been developed which compensates simultaneously for attenuation, scatter, and resolution variation. The scattered photons in the primary-energy-window measurements are approximately removed by subtracting the weighted scatter-energy-window samples. The resolution variation is corre...

Journal: :Journal of nuclear medicine : official publication, Society of Nuclear Medicine 1970
J D Bernard R A McDonald J A Nesmith

attached to an external detector system, the thyroid uptake of iodine was measured at 6 and 24 hr. The external detector consisted of a 1Â1⁄4x 1 in. NaI(Tl) scintillation crystal and a flat-field lead collimator. A Lucite extension of the collimator was shaped to fit the neck and assure good geometry with a neck-to crystal distance of 20 cm. A standard neck phantom was used with standard capsul...

2001
Tianfang Li Junhai Wen Zhengrong Liang

The authors present a new method to compensate for the spatially variant detector response in single photon emission computed tomography (SPECT) with varying focal-length fan-beam (VFF) geometry. In this method, the deblurred projection is explicitly expressed as an integral of the collimator blurred data and the fully calibrated system kernel matrix with certain transforms. It needs a little m...

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