%0 Journal Article
%A Aigner, Christoph Stefan
%A Dietrich-Conzelmann, Sebastian
%A Lutz, Max
%A Krüger, Felix
%A Schmitter, Sebastian
%T Tailored and universal parallel transmit broadband pulses for homogeneous 3D excitation of the human heart at 7T.
%J Magnetic resonance in medicine
%V 92
%N 2
%@ 1522-2594
%C New York, NY [u.a.]
%I Wiley-Liss
%M DKFZ-2024-00484
%P 730-740
%D 2024
%Z #LA:E020# / 2024 Aug;92(2):730-740
%X 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 + 
%X <br clear="all" /><table border="0" width="100%"><tr><td>
%X <table align="center" cellspacing="0"  cellpadding="2"><tr><td nowrap="nowrap" align="center">
%X  B<sub>1</sub><sup>+</sup> </td></tr></table>
%X </td></tr></table>
%X 
%X  -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 + 
%X <br clear="all" /><table border="0" width="100%"><tr><td>
%X <table align="center" cellspacing="0"  cellpadding="2"><tr><td nowrap="nowrap" align="center">
%X  B<sub>1</sub><sup>+</sup> </td></tr></table>
%X </td></tr></table>
%X 
%X  -maps, and UPs were calculated using 22 B 1 + 
%X <br clear="all" /><table border="0" width="100%"><tr><td>
%X <table align="center" cellspacing="0"  cellpadding="2"><tr><td nowrap="nowrap" align="center">
%X  B<sub>1</sub><sup>+</sup> </td></tr></table>
%X </td></tr></table>
%X 
%X  -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 + 
%X <br clear="all" /><table border="0" width="100%"><tr><td>
%X <table align="center" cellspacing="0"  cellpadding="2"><tr><td nowrap="nowrap" align="center">
%X  B<sub>1</sub><sup>+</sup> </td></tr></table>
%X </td></tr></table>
%X 
%X  -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.
%K 7 Tesla (Other)
%K body MRI (Other)
%K broadband (Other)
%K parallel transmission (Other)
%K universal pulse (Other)
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:38440957
%R 10.1002/mrm.30072
%U https://inrepo02.dkfz.de/record/288813