TY  - JOUR
AU  - Aigner, Christoph Stefan
AU  - Dietrich-Conzelmann, Sebastian
AU  - Lutz, Max
AU  - Krüger, Felix
AU  - Schmitter, Sebastian
TI  - Tailored and universal parallel transmit broadband pulses for homogeneous 3D excitation of the human heart at 7T.
JO  - Magnetic resonance in medicine
VL  - 92
IS  - 2
SN  - 1522-2594
CY  - New York, NY [u.a.]
PB  - Wiley-Liss
M1  - DKFZ-2024-00484
SP  - 730-740
PY  - 2024
N1  - #LA:E020# / 2024 Aug;92(2):730-740
AB  - To research and evaluate the performance of broadband tailored kT-point pulses (TP) and universal pulses (UP) for homogeneous excitation of the human heart at 7T.Relative 3D B 1 + 
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AB  -  B<sub>1</sub><sup>+</sup> </td></tr></table>
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AB  -  -maps of the thorax were acquired from 29 healthy volunteers. TP and UP were designed using the small-tip-angle approximation for a different composition of up to seven resonance frequencies. TP were computed for each of the 29 B 1 + 
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AB  -  B<sub>1</sub><sup>+</sup> </td></tr></table>
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AB  -  -maps, and UPs were calculated using 22 B 1 + 
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AB  -  B<sub>1</sub><sup>+</sup> </td></tr></table>
AB  - </td></tr></table>
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AB  -  -maps and tested in seven testcases. The performance of the pulses was analyzed using the coefficient of variation (CV) in the 3D heart volumes. The 3D gradient-echo (GRE) scans were acquired for the seven testcases to qualitatively validate the B 1 + 
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AB  -  -predictions.Single- and double-frequency optimized pulses achieved homogeneity in flip angle (FA) for the frequencies they were optimized for, while the broadband pulses achieved uniformity in FA across a 1300 Hz frequency range.Broadband TP and UP can be used for homogeneous excitation of the heart volume across a 1300 Hz frequency range, including the water and the main six fat peaks, or with longer pulse durations and higher FAs for a smaller transmit bandwidth. Moreover, despite large inter-volunteer variations, broadband UP can be used for calibration-free 3D heart FA homogenization in time-critical situations.
KW  - 7 Tesla (Other)
KW  - body MRI (Other)
KW  - broadband (Other)
KW  - parallel transmission (Other)
KW  - universal pulse (Other)
LB  - PUB:(DE-HGF)16
C6  - pmid:38440957
DO  - DOI:10.1002/mrm.30072
UR  - https://inrepo02.dkfz.de/record/288813
ER  -