نتایج جستجو برای: mlem

تعداد نتایج: 102  

Journal: :iranian journal of nuclear medicine 0
mohsen hajizadeh saffar medical physics research center, school of medicine, mashhad university of medical sciences, mashhad, iran shabnam oloomi medical physics department, mashhad university of medical science, mashhad, iran peter knoll department of nuclear medicine, wilhelminenspital, vienna, austria hadi taleshi department of medical physics, faculty of medical sciences, tarbiat modares university, tehran, iran

introduction: scattered photon is one of the main defects that degrade the quality and quantitative accuracy of nuclear medicine images. accurate estimation of scatter in projection data of spect is computationally extremely demanding for activity distribution in uniform and non-uniform dense media. methods: the objective of this paper is to develop and validate a scatter correction technique t...

Journal: :Proceedings of SPIE--the International Society for Optical Engineering 2010
Weihua Zhou Xin Qian Jianping Lu Otto Zhou Ying Chen

Digital breast tomosynthesis is a new technique to improve the early detection of breast cancer by providing three-dimensional reconstruction volume of the object with limited-angle projection images. This paper investigated the image reconstruction with a standard biopsy training breast phantom using a novel multi-beam X-ray sources breast tomosynthesis system. Carbon nanotube technology based...

2017
Shabnam Khorasani Gerdekoohi Naser Vosoughi Kaveh Tanha Majid Assadi Pardis Ghafarian Arman Rahmim Mohammad Reza Ay

PURPOSE Presence of photon attenuation severely challenges quantitative accuracy in single-photon emission computed tomography (SPECT) imaging. Subsequently, various attenuation correction methods have been developed to compensate for this degradation. The present study aims to implement an attenuation correction method and then to evaluate quantification accuracy of attenuation correction in s...

Journal: :Physics in medicine and biology 2011
Roel Van Holen Steven Staelens Stefaan Vandenberghe

Parallel and converging hole collimators are most frequently used in nuclear medicine. Less common is the use of rotating slat collimators for single photon emission computed tomography (SPECT). The higher photon collection efficiency, inherent to the geometry of rotating slat collimators, results in much lower noise in the data. However, plane integrals contain spatial information in only one ...

2001
U. Heinrichs

Within the Crystal Clear Collaboration (CCC), four centers are developing second generation high performance small animal positron emission tomography (PET) scanners for different kinds of animals and medical applications. The first prototypes are photomultiplier tube (PMT)-based systems including depth of interaction (DOI) detection by using a phoswich layer of lutetium oxyorthosilicate (LSO) ...

C. Geng, C. Gong, D. Shu, H. Yu, S. Fatemi, W. Shao, X. Tang,

Background: Boron neutron capture therapy (BNCT) is a binary radiotherapy combining biochemical targeting with neutron irradiation. However, monitoring the boron distribution is a fundamental problem in BNCT. Prompt gamma rays emitted by boron capture reaction can be used to address the issue. Materials and Methods: The general-purpose Monte Carlo toolkits Geant4 and MCNP were used for the simu...

2015
Ester D’Hoe Pieter Mollet Ekaterina Mikhaylova Michel Defrise Stefaan Vandenberghe

MEDISIP Medical Imaging and Signal Processing Group, Ghent University, IBBT-IBiTech, iMinds Medical IT, Ghent, Belgium In Time-of-Flight PET/MRI systems accurate attenuation correction, based on the MRI image, is not straight forward. An alternative is attenuation correction based on emission data only. This is for instance done by simultaneous reconstruction of attenuation and activity with th...

Hadi Taleshi Mohsen Saffar Peter Knoll, Shabnam Oloomi

Introduction: Scattered photon is one of the main defects that degrade the quality and quantitative accuracy of nuclear medicine images. Accurate estimation of scatter in projection data of SPECT is computationally extremely demanding for activity distribution in uniform and non-uniform dense media. Methods: The objective of this paper is to develop and validate a scatter correction technique ...

Journal: :iranian journal of nuclear medicine 2013
mohsen hajizadeh saffar shabnam oloomi peter knoll hadi taleshi

introduction: scattered photon is one of the main defects that degrade the quality and quantitative accuracy of nuclear medicine images. accurate estimation of scatter in projection data of spect is computationally extremely demanding for activity distribution in uniform and non-uniform dense media. methods: the objective of this paper is to develop and validate a scatter correction technique ...

Journal: :EJNMMI physics 2014
Robin de Nijs Björn Neumann Jensen Jann Mortensen

Due to low counts in an (111)In single photon emission computed tomography (SPECT) scan, a large part of the head was missing in the reconstructed images on Philips Extended Brilliance Workspace (EBW) and IntelliSpace Portal (ISP) workstations. This problem occurred for the ordered subsets expectation maximization (OSEM) algorithm with and without resolution recovery (Astonish), but not for fil...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید