نتایج جستجو برای: osem

تعداد نتایج: 265  

2006
P. Gantet

SPECT imaging suffers from low spatial resolution and statistical noise. Consequently, the contrast of small structures is reduced, visual detection of defects is limited and exact quantification is difficult. To improve the contrast, it is possible to incorporate a blurring model into the iterative reconstruction process such as OSEM3D. This approach is well known to be effective, but time con...

Journal: :Journal of instrumentation : an IOP and SISSA journal 2014
D Uzun G De Lorenzo M Kolstein M Chmeissani

Over the last two decades there have been a growing number of designs for positron emission tomography (PET) cameras optimized to image the breast. These devices, commonly known as positron emission mammography (PEM) cameras allow much more spatial resolution by putting the photon detectors directly on the breast. PEM cameras have a compact geometry with a restricted field of view (FOV) thus ex...

2008
Mohsen Hajizadeh Seyed Rasoul Zakavi Maryam Naji

Introduction: Ordered subset expectation maximization (OSEM), is an effective iterative method for SPECT image reconstruction. The aim of this study is the evaluation of the role of system matrix in OSEM image reconstruction method using four different physical beam radiation models with three detection configurations. Methods: SPECT was done with an arc of 180 degree in 32 projections after in...

Journal: :Applied Mathematics and Computer Science 2011
Damian Borys Katarzyna Szczucka-Borys Kamil Gorczewski

A method for system matrix calculation in the case of iterative reconstruction algorithms in SPECT was implemented and tested. Due to a complex mathematical description of the geometry of the detector set-up, we developed a method for system matrix computation that is based on direct measurements of the detector response. In this approach, the influence of the acquisition equipment on the image...

2017
Livia Tossici-Bolt John C. Dickson Terez Sera Jan Booij Susanne Asenbaun-Nan Maria C. Bagnara Thierry Vander Borght Cathrine Jonsson Robin de Nijs Swen Hesse Pierre M. Koulibaly Umit O. Akdemir Michel Koole Klaus Tatsch Andrea Varrone

BACKGROUND [123I]FP-CIT is a well-established radiotracer for the diagnosis of dopaminergic degenerative disorders. The European Normal Control Database of DaTSCAN (ENC-DAT) of healthy controls has provided age and gender-specific reference values for the [123I]FP-CIT specific binding ratio (SBR) under optimised protocols for image acquisition and processing. Simpler reconstruction methods, how...

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