Journal Article

DKFZ-2021-00468

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Whole-brain quantitative CEST MRI at 7T using parallel transmission methods and B 1 + correction.

Liebert, A. ; Tkotz, K. ; Herrler, J. ; Linz, P. ; Mennecke, A. ; German, A. ; Liebig, P. ; Gumbrecht, R. ; Schmidt, M. ; Doerfler, A. ; Uder, M. ; Zaiss, M. ; Nagel, A. (Last author)DKFZ*

2021
Wiley-Liss New York, NY [u.a.]

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Please use a persistent id in citations: doi:10.1002/mrm.28745

Abstract: 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% for 3 measurements in a single volunteer.A combination of MIMOSA FOCUS with a single-point B 1 + correction can be used to achieve quantitative CEST measurements at ultra-high magnetic field strengths. Compared to previous B 1 + correction methods, acquisition time can be reduced as additional scans required for B 1 + correction can be omitted.

Keyword(s): 7T ; chemical exchange saturation transfer ; fast-online customized pulses ; multiple interleaved mode saturation ; parallel transmission ; spiral non-selective trajectory

Note: #LA:E020# / 86(1):346-362

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Contributing Institute(s):

1. E020 Med. Physik in der Radiologie (E020)

Research Program(s):

1. 315 - Bildgebung und Radioonkologie (POF4-315) (POF4-315)

Appears in the scientific report 2021

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Database coverage:
; BIOSIS Previews ; Biological Abstracts ; Clarivate Analytics Master Journal List ; Current Contents - Clinical Medicine ; Current Contents - Life Sciences ; DEAL Wiley ; Essential Science Indicators ; IF < 5 ; JCR ; Nationallizenz ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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