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K-space trajectory mapping and its application for ultrashort Echo time imaging
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SYSNO ASEP 0470615 Document Type J - Journal Article R&D Document Type Journal Article Subsidiary J Článek ve WOS Title K-space trajectory mapping and its application for ultrashort Echo time imaging Author(s) Latta, P. (CZ)
Starčuk jr., Zenon (UPT-D) RID, ORCID, SAI
Gruwel, M. L. H. (CA)
Weber, M.H. (CA)
Tomanek, B. (CA)Number of authors 5 Source Title Magnetic Resonance Imaging. - : Elsevier - ISSN 0730-725X
Roč. 36, February (2017), s. 68-76Number of pages 9 s. Publication form Print - P Language eng - English Country US - United States Keywords gradient imperfections ; K-space deviation ; trajectrory estaimation ; ultrashort echo time Subject RIV FS - Medical Facilities ; Equipment OECD category Medical engineering R&D Projects GA15-12607S GA ČR - Czech Science Foundation (CSF) Institutional support UPT-D - RVO:68081731 UT WOS 000393536100010 EID SCOPUS 84994508591 DOI 10.1016/j.mri.2016.10.012 Annotation MR images are affected by system delays and gradient field imperfections which induce discrepancies between prescribed and actual k-space trajectories. This could be even more critical for non-Cartesian data acquisitions where even a small deviation from the assumed k-space trajectory results in severe image degradation and artifacts. Knowledge of the actual k-space trajectories is therefore crucial and can be incorporated in the reconstruction of high quality non-Cartesian images. A novel MR method for the calibration of actual gradient waveforms was developed using a combination of phase encoding increments and subsequent detection of the exact time point at which the corresponding trajectory is crossing the k-space origin. The measured sets of points were fitted to a parametrical model to calculate the complete actual acquisition trajectory. Measurements performed on phantoms and volunteers, positioned both in- and off-isocenter of the magnet, clearly demonstrate the improvement in reconstructed ultrashort echo time (UTE) images, when information from calibration of k-space sampling trajectories is employed in the MR image reconstruction procedure. The unique feature of the proposed method is its robustness and simple experimental setup, making it suitable for quick acquisition trajectory calibration procedures e.g. for non-Cartesian radial fast imaging. Workplace Institute of Scientific Instruments Contact Martina Šillerová, sillerova@ISIBrno.Cz, Tel.: 541 514 178 Year of Publishing 2017
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