TY  - JOUR
AU  - Liebert, Andrzej
AU  - Tkotz, Katharina
AU  - Herrler, Jürgen
AU  - Linz, Peter
AU  - Mennecke, Angelika
AU  - German, Alex
AU  - Liebig, Patrick
AU  - Gumbrecht, Rene
AU  - Schmidt, Manuel
AU  - Doerfler, Arnd
AU  - Uder, Michael
AU  - Zaiss, Moritz
AU  - Nagel, Armin
TI  - Whole-brain quantitative CEST MRI at 7T using parallel transmission methods and B 1 + correction.
JO  - Magnetic resonance in medicine
VL  - 86
IS  - 1
SN  - 1522-2594
CY  - New York, NY [u.a.]
PB  - Wiley-Liss
M1  - DKFZ-2021-00468
SP  - 346-362
PY  - 2021
N1  - #LA:E020# / 86(1):346-362
AB  - To enable whole-brain quantitative CEST MRI at ultra-high magnetic field strengths (B0 ≥ 7T) within short acquisition times.Multiple interleaved mode saturation (MIMOSA) was combined with fast online-customized (FOCUS) parallel transmission (pTx) excitation pulses and B 1 + correction to achieve homogenous whole-brain coverage. Examinations of 13 volunteers were performed on a 7T MRI system with 3 different types of pulse sequences: (1) saturation in circular polarized (CP) mode and CP mode readout, (2) MIMOSA and CP readout, and (3) MIMOSA and FOCUS readout. For comparison, the inverse magnetic transfer ratio metric for relayed nuclear Overhauser effect and amide proton transfer were calculated. To investigate the number of required acquisitions for a good B 1 + correction, 4 volunteers were measured with 6 different B1 amplitudes. Finally, time point repeatability was investigated for 6 volunteers.MIMOSA FOCUS sequence using B 1 + correction, with both single and multiple points, reduced inhomogeneity of the CEST contrasts around the occipital lobe and cerebellum. Results indicate that the most stable inter-subject coefficient of variation was achieved using the MIMOSA FOCUS sequence. Time point repeatability of MIMOSA FOCUS with single-point B 1 + correction showed a maximum coefficient of variation below 8
KW  - 7T (Other)
KW  - chemical exchange saturation transfer (Other)
KW  - fast-online customized pulses (Other)
KW  - multiple interleaved mode saturation (Other)
KW  - parallel transmission (Other)
KW  - spiral non-selective trajectory (Other)
LB  - PUB:(DE-HGF)16
C6  - pmid:33634505
DO  - DOI:10.1002/mrm.28745
UR  - https://inrepo02.dkfz.de/record/167634
ER  -