Status: Bibliographieeintrag
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| Online-Ressource |
Verfasst von: | Davids, Mathias [VerfasserIn]  |
| Schad, Lothar R. [VerfasserIn]  |
Titel: | Fast three-dimensional inner volume excitations using parallel transmission and optimized k-space trajectories |
Verf.angabe: | Mathias Davids, Lothar R. Schad, Lawrence L. Wald, and Bastien Guérin |
Jahr: | 2016 |
Jahr des Originals: | 2015 |
Umfang: | 13 S. |
Fussnoten: | Gesehen am 04.07.2019 ; Published online 3 November 2015 in Wiley Online Library |
Titel Quelle: | Enthalten in: Magnetic resonance in medicine |
Ort Quelle: | New York, NY [u.a.] : Wiley-Liss, 1984 |
Jahr Quelle: | 2016 |
Band/Heft Quelle: | 76(2016), 4, Seite 1170-1182 |
ISSN Quelle: | 1522-2594 |
Abstract: | Purpose To design short parallel transmission (pTx) pulses for excitation of arbitrary three-dimensional (3D) magnetization patterns. Methods We propose a joint optimization of the pTx radiofrequency (RF) and gradient waveforms for excitation of arbitrary 3D magnetization patterns. Our optimization of the gradient waveforms is based on the parameterization of k-space trajectories (3D shells, stack-of-spirals, and cross) using a small number of shape parameters that are well-suited for optimization. The resulting trajectories are smooth and sample k-space efficiently with few turns while using the gradient system at maximum performance. Within each iteration of the k-space trajectory optimization, we solve a small tip angle least-squares RF pulse design problem. Our RF pulse optimization framework was evaluated both in Bloch simulations and experiments on a 7T scanner with eight transmit channels. Results Using an optimized 3D cross (shells) trajectory, we were able to excite a cube shape (brain shape) with 3.4% (6.2%) normalized root-mean-square error in less than 5 ms using eight pTx channels and a clinical gradient system (Gmax?=?40 mT/m, Smax?=?150 T/m/s). This compared with 4.7% (41.2%) error for the unoptimized 3D cross (shells) trajectory. Incorporation of B0 robustness in the pulse design significantly altered the k-space trajectory solutions. Conclusion Our joint gradient and RF optimization approach yields excellent excitation of 3D cube and brain shapes in less than 5 ms, which can be used for reduced field of view imaging and fat suppression in spectroscopy by excitation of the brain only. Magn Reson Med 76:1170?1182, 2016. ? 2015 Wiley Periodicals, Inc. |
DOI: | doi:10.1002/mrm.26021 |
URL: | Bitte beachten Sie: Dies ist ein Bibliographieeintrag. Ein Volltextzugriff für Mitglieder der Universität besteht hier nur, falls für die entsprechende Zeitschrift/den entsprechenden Sammelband ein Abonnement besteht oder es sich um einen OpenAccess-Titel handelt.
Volltext ; Verlag: https://doi.org/10.1002/mrm.26021 |
| Volltext: https://onlinelibrary.wiley.com/doi/full/10.1002/mrm.26021 |
| DOI: https://doi.org/10.1002/mrm.26021 |
Datenträger: | Online-Ressource |
Sprache: | eng |
Sach-SW: | B0 robustness |
| inner volume excitation |
| k-space trajectory optimization |
| Parallel transmit |
| spatially selective excitation |
K10plus-PPN: | 166861023X |
Verknüpfungen: | → Zeitschrift |
Fast three-dimensional inner volume excitations using parallel transmission and optimized k-space trajectories / Davids, Mathias [VerfasserIn]; 2016 (Online-Ressource)
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