%0 Journal Article
%A Tkotz, Katharina
%A Liebert, Andrzej
%A Gast, Lena V
%A Zeiger, Paula
%A Uder, Michael
%A Zaiss, Moritz
%A Nagel, Armin
%T Multi-echo-based fat artifact correction for CEST MRI at 7 T.
%J Magnetic resonance in medicine
%V 91
%N 2
%@ 1522-2594
%C New York, NY [u.a.]
%I Wiley-Liss
%M DKFZ-2023-01968
%P 481-496
%D 2024
%Z #LA:E020# / 2024 Feb;91(2):481-496
%X CEST MRI is influenced by fat signal, which can reduce the apparent CEST contrast or lead to pseudo-CEST effects. Our goal was to develop a fat artifact correction based on multi-echo fat-water separation that functions stably for 7 T knee MRI data.Our proposed algorithm utilizes the full complex data and a phase demodulation with an off-resonance map estimation based on the Z-spectra prior to fat-water separation to achieve stable fat artifact correction. Our method was validated and compared to multi-echo-based methods originally proposed for 3 T by Bloch-McConnell simulations and phantom measurements. Moreover, the method was applied to in vivo 7 T knee MRI examinations and compared to Gaussian fat saturation and a published single-echo Z-spectrum-based fat artifact correction method.Phase demodulation prior to fat-water separation reduced the occurrence of fat-water swaps. Utilizing the complex signal data led to more stable correction results than working with magnitude data, as was proposed for 3 T. Our approach reduced pseudo-nuclear Overhauser effects compared to the other correction methods. Thus, the mean asymmetry contrast at 3.5 ppm in cartilage over five volunteers increased from -9.2
%K 7 T (Other)
%K CEST (Other)
%K fat artifact (Other)
%K fat-water separation (Other)
%K knee imaging (Other)
%K nuclear Overhauser effect (Other)
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:37753844
%R 10.1002/mrm.29863
%U https://inrepo02.dkfz.de/record/283203