نتایج جستجو برای: collimator detector response

تعداد نتایج: 1033857  

2009
Xiaoqin J. Guo Richard C. Hagenauer Ronald M. Keyser

Proper characterization of waste is important to reduce the costs of disposal. The requirement for short data collection time often means putting the detector as close to the waste container as possible. Nondestructive assay of gamma ray emitting nuclear waste requires modeling because preparing a standard to match the physical and radiological properties of any waste item is not possible. Seve...

Journal: :Journal of nuclear medicine : official publication, Society of Nuclear Medicine 2000
G El Fakhri I Buvat H Benali A Todd-Pokropek R Di Paola

UNLABELLED We determined the relative effect of corrections for scatter, depth-dependent collimator response, attenuation, and finite spatial resolution on various image characteristics in cardiac SPECT. METHODS Monte Carlo simulations and real acquisition of a 99mTc cardiac phantom were performed under comparable conditions. Simulated and acquired data were reconstructed using several correc...

2001
V. Mandic M. B. Crisler D. Driscoll J. Emes R. J. Gaitskell S. Kamat P. Meunier B. Young

The Ge and Si detectors developed by the Cryogenic Dark Matter Search (CDMS) II experiment rely on the simultaneous detection of athermal phonons and ionization produced by interactions in the crystal. The athermal phonons not only provide the total energy deposited during an interaction, but also carry information about the position of the interaction. We describe extracting this information f...

1997
Anne C. Sauve Alfred O. Hero W. Leslie

transition matrix in 3D Electronically Collimated SPECT Anne C. Sauve1, Alfred O. Hero1, W. Leslie Rogers2 and Neal H. Clinthorne2 January 15, 1997 Abstract In this paper we will present numerical studies of the performance of a 3D Compton camera being developed at the University of Michigan. We present a physical model of the camera which exploits symmetries and an adapted spatial sampling pat...

2016
Eero Hippeläinen Mikko Tenhunen Hanna Mäenpää Antti Sohlberg

BACKGROUND In targeted radionuclide therapy (TRT), accurate quantification using SPECT/CT images is important for optimizing radiation dose delivered to both the tumour and healthy tissue. Quantitative SPECT images are regularly reconstructed using the ordered subset expectation maximization (OSEM) algorithm with various compensation methods such as attenuation (A), scatter (S) and detector and...

Journal: :Medical physics 2013
M Safavi-Naeini Z Han D Cutajar S Guatelli M Petasecca M L F Lerch D R Franklin J Jakubek S Pospisil J Bucci M Zaider A B Rosenfeld

PURPOSE High dose rate (HDR) brachytherapy is a form of radiation therapy for treating prostate cancer whereby a high activity radiation source is moved between predefined positions inside applicators inserted within the treatment volume. Accurate positioning of the source is essential in delivering the desired dose to the target area while avoiding radiation injury to the surrounding tissue. I...

Journal: :Medical physics 2014
M Khan J Rehman J Chow

PURPOSE The purpose of this study is to investigate the dose-volume variations of planning target volume (PTV) and organs-at-risk (OARs) in prostate volumetric modulated arc therapy (VMAT) when using different collimator angles. It is because collimator angle awareness is essential for planner to produce an optimal prostate VMAT plan in a rational time. METHODS Single-arc VMAT plans at differ...

A. Ismail, B. Jerby, R. Shweikani,

Background: : Due to the difficulties of locally obtaining ZnS(Ag), preliminary investigation of the radioluminescence characterization of Zinc oxide (ZnO) for alpha particle detection was performed. Materials and Methods: The scintillation properties of ZnO films were tested using alpha sources                &nbsp...

Journal: :Journal of nuclear medicine : official publication, Society of Nuclear Medicine 2005
Youngho Seo Kenneth H Wong Mingshan Sun Benjamin L Franc Randall A Hawkins Bruce H Hasegawa

UNLABELLED (111)In-Capromab pendetide imaging is indicated for postprostatectomy patients at risk for residual or recurrent disease. However, this study is complicated by relatively long times for tumor uptake and background washout that require imaging to be performed several days after radiopharmaceutical administration. In addition, (111)In-capromab pendetide demonstrates uptake in normal st...

2000
R. A. Kroeger W. N. Johnson J. D. Kurfess B. F. Phlips E. A. Wulf

Modern developments in detector and electronics technology now enable a new generation of gamma ray detectors based on recording each and every energy loss associated with an incident gamma ray. The energy of an incident gamma ray is determined by measuring the positions of the first three interactions, and the energy loss of the first two. The direction of the incident gamma ray is restricted ...

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