نتایج جستجو برای: ordered subsets expectation maximization

تعداد نتایج: 139368  

Journal: :Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism 2010
Jurgen E M Mourik Mark Lubberink Floris H P van Velden Reina W Kloet Bart N M van Berckel Adriaan A Lammertsma Ronald Boellaard

The aim of this study was to validate in vivo the accuracy of a reconstruction-based partial volume correction (PVC), which takes into account the point spread function of the imaging system. The NEMA NU2 Image Quality phantom and five healthy volunteers (using [(11)C]flumazenil) were scanned on both HR+ and high-resolution research tomograph (HRRT) scanners. HR+ data were reconstructed using n...

2012
S. Kazemi S. Yatawatta S. Zaroubi

The main objective of this work is to accelerate the MaximumLikelihood (ML) estimation procedure for radio interferometric direction dependent self-calibration. We introduce the OS-SAGE radio interferometric calibration method, as a combination of the Ordered-Subsets (OS) method with the Space Alternating Generalized Expectation maximization (SAGE) calibration technique. The OS method speeds up...

Journal: :Physics in medicine and biology 2004
Kisung Lee Paul E Kinahan Jeffrey A Fessler Robert S Miyaoka Marie Janes Tom K Lewellen

We present a pragmatic approach to image reconstruction for data from the micro crystal elements system (MiCES) fully 3D mouse imaging positron emission tomography (PET) scanner under construction at the University of Washington. Our approach is modelled on fully 3D image reconstruction used in clinical PET scanners, which is based on Fourier rebinning (FORE) followed by 2D iterative image reco...

2017
Daniëlle Koopman Maureen Groot Koerkamp Pieter L Jager Hester Arkies Siert Knollema Cornelis H Slump Pedro G Sanches Jorn A van Dalen

BACKGROUND Our aim was to evaluate if a recently introduced TOF PET system with digital photon counting technology (Philips Healthcare), potentially providing an improved image quality over analogue systems, can fulfil EANM research Ltd (EARL) accreditation specifications for tumour imaging with FDG-PET/CT. FINDINGS We have performed a phantom study on a digital TOF PET system using a NEMA NU...

Journal: :Medical physics 2016
Vinicius O Menezes Marcos A D Machado Cleiton C Queiroz Susana O Souza Francesco d'Errico Mauro Namías Ticiana F Larocca Milena B P Soares

PURPOSE This paper describes a method to achieve consistent clinical image quality in (18)F-FDG scans accounting for patient habitus, dose regimen, image acquisition, and processing techniques. METHODS Oncological PET/CT scan data for 58 subjects were evaluated retrospectively to derive analytical curves that predict image quality. Patient noise equivalent count rate and coefficient of variat...

2008
Bao-dong LIU Li ZENG Dong-jiang JI

The nondestructive testing (NDT) of long object (such as pipeline) has significant value. Computed tomography (CT) is able to generate 3D images and display the inner defects of the inspected object. Sometimes the long object fixed outdoors can’t be rotated, and the rotating of the X-ray source and detector is also difficult. So the linear scan CT, translating the X-ray source and detector alon...

2005
Justin Dauwels Sascha Korl Hans-Andrea Loeliger

x f(x, θ) log f(x, θ) exists for all θ and θ. In principle, one can apply the sum-product algorithm in order to find (1), which involves the following two steps [2]: 1. Determine f(θ) by sum-product message passing. 2. Maximization step: compute θmax △ = argmaxθ f(θ). This procedure is often not feasible, since • When the variable x is continuous, the sum-product rule may lead to intractable in...

Objective(s): The aim of this study is to examine the effect of different smoothing filters on the image quality and SUVmax to achieve the guideline recommended positron emission tomography (PET) image without harmonization. Methods: We used a Biograph mCT PET scanner. A National Electrical Manufacturers Association (NEMA) the International Electrotechnical Commission (IEC) body phantom was fil...

Journal: :EURASIP Journal on Audio, Speech, and Music Processing 2020

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