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  1. Article: Towards accurate

    Raskin, Stanislav / Gamliel, Dan / Abookasis, David / Ben-Haim, Simona / Chicheportiche, Alexandre

    EJNMMI physics

    2023  Volume 10, Issue 1, Page(s) 5

    Abstract: Background: Conventional calibration of the gamma camera consists of the calculation of calibration factors (CFs) (ratio of counts/cc and true concentration activity) as the function of the volume of interest (VOI). However, such method shows ... ...

    Abstract Background: Conventional calibration of the gamma camera consists of the calculation of calibration factors (CFs) (ratio of counts/cc and true concentration activity) as the function of the volume of interest (VOI). However, such method shows inconsistent results when the background activity varies. The aim of the present study was to propose a new calibration method by considering the sphere-to-background counts/voxel ratio (SBVR) in addition to the VOI for CFs calculation. A PET cylindrical flood phantom, a NEMA IQ body phantom, a Data spectrum Torso Phantom (ECT/TOR/P) and a LK-S Kyoto Liver/Kidney phantom were used. The NEMA IQ phantom was used to calibrate the camera and to produce CFs for the different spheres volumes and for varying sphere-to-background activity ratios. The spheres were filled with a uniform activity concentration of
    Results: The relative errors in quantification using the NEMA IQ phantom with the new calibration method were 0.16%, 5.77%, 9.34% for the large, medium and small sphere, respectively, for a time per view of 30-s. The conventional calibration method gave errors of 3.65%, 6.65%, 30.28% for 30-s. The LK-S Kyoto Liver/Kidney Phantom resulted in quantification errors of 3.40%, 2.14%, 11.18% for the large, medium and small spheres, respectively, for 30-s; compared to 11.31%, 17.54%, 14.43% for 30-s, respectively, for the conventional method. Similar results were obtained for shorter acquisitions times with 20-s and 10-s time per view.
    Conclusion: These results suggest that SBVR allows to improve quantification accuracy. The shorter time-per-view acquisitions had similar relative differences compared to the full-time acquisition which allows shorter imaging times with
    Language English
    Publishing date 2023-01-23
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 2768912-8
    ISSN 2197-7364
    ISSN 2197-7364
    DOI 10.1186/s40658-023-00526-x
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Book: Stochastic processes in magnetic resonance

    Gamliel, Dan / Levanon, Haim

    1995  

    Author's details Dan Gamliel & Haim Levanon
    Language English
    Size IX, 335 S, graph. Darst
    Publisher World Scientific
    Publishing place Singapore u.a.
    Document type Book
    Note Literaturangaben
    ISBN 9810222270 ; 9789810222277
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

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  3. Book ; Online: Stochastic processes in magnetic resonance

    Gamliel, Dan / Levanon, Haim

    1995  

    Abstract: This book describes methods for calculating magnetic resonance spectra which are observed in the presence of random processes. The emphasis is on the stochastic Liouville equation (SLE), developed mainly by Kubo and applied to magnetic resonance mostly ... ...

    Institution e-libro, Corp
    Author's details Dan Gamliel & Haim Levanon
    Abstract This book describes methods for calculating magnetic resonance spectra which are observed in the presence of random processes. The emphasis is on the stochastic Liouville equation (SLE), developed mainly by Kubo and applied to magnetic resonance mostly by J H Freed and his co-workers. Following an introduction to the use of density matrices in magnetic resonance, a unified treatment of Bloch-Redfield relaxation theory and chemical exchange theory is presented. The SLE formalism is then developed and compared to the other relaxation theories. Methods for solving the SLE are explained in detail
    Keywords Magnetic resonance ; Simulated annealing (Mathematics) ; Stochastic processes
    Language English
    Size Online-Ressource (ix, 335 p), ill
    Publisher World Scientific
    Publishing place Singapore ;River Edge, NJ
    Document type Book ; Online
    Note Includes bibliographical references and index
    ISBN 9789810222277 ; 9789812831040 ; 9810222270 ; 9812831045
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

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