Suzan Akbey1, Philipp Ehses1, Rüdiger Stirnberg1, Moritz Zaiss2, Tony Stöcker1,3. 1. German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany. 2. Max-Planck Institute for Biological Cybernetics, Tübingen, Germany. 3. Department of Physics and Astronomy, University of Bonn, Bonn, Germany.
Abstract
PURPOSE: The aim of this work is to develop a fast and robust CEST sequence in order to allow the acquisition of a whole-brain imaging volume after a single preparation block (snapshot acquisition). METHODS: A 3D-CEST sequence with an optimized 3D-EPI readout module was developed, which acquires the complete k-space data following a single CEST preparation for 1 saturation offset. Whole-brain mapping of the Z-spectrum with 2 mm isotropic resolution is achieved at 68 saturation frequencies in 5 minutes (4.33 s per offset). We analyzed the B 1 distribution in order to optimize B 1 correction and to provide accurate CEST quantification across the whole brain. RESULTS: We obtained maps for 3 different CEST contrasts from 4 healthy subjects. Based on our B 1 distribution analysis, we conclude that 3 B 1 sampling points allow for sufficient compensation of B 1 variations across most of the brain. Two brain regions, the cerebellum and the temporal lobes, are difficult to quantify at 7 T due to very low B 1 that was achieved in these regions. CONCLUSIONS: The proposed sequence enables robust acquisition of 2 mm isotropic whole-brain CEST maps at 7 Tesla within a total scan time of 16 minutes.
PURPOSE: The aim of this work is to develop a fast and robust CEST sequence in order to allow the acquisition of a whole-brain imaging volume after a single preparation block (snapshot acquisition). METHODS: A 3D-CEST sequence with an optimized 3D-EPI readout module was developed, which acquires the complete k-space data following a single CEST preparation for 1 saturation offset. Whole-brain mapping of the Z-spectrum with 2 mm isotropic resolution is achieved at 68 saturation frequencies in 5 minutes (4.33 s per offset). We analyzed the B 1 distribution in order to optimize B 1 correction and to provide accurate CEST quantification across the whole brain. RESULTS: We obtained maps for 3 different CEST contrasts from 4 healthy subjects. Based on our B 1 distribution analysis, we conclude that 3 B 1 sampling points allow for sufficient compensation of B 1 variations across most of the brain. Two brain regions, the cerebellum and the temporal lobes, are difficult to quantify at 7 T due to very low B 1 that was achieved in these regions. CONCLUSIONS: The proposed sequence enables robust acquisition of 2 mm isotropic whole-brain CEST maps at 7 Tesla within a total scan time of 16 minutes.
Authors: Kai Herz; Sebastian Mueller; Or Perlman; Maxim Zaitsev; Linda Knutsson; Phillip Zhe Sun; Jinyuan Zhou; Peter van Zijl; Kerstin Heinecke; Patrick Schuenke; Christian T Farrar; Manuel Schmidt; Arnd Dörfler; Klaus Scheffler; Moritz Zaiss Journal: Magn Reson Med Date: 2021-05-07 Impact factor: 3.737
Authors: Laura Mancini; Stefano Casagranda; Guillaume Gautier; Philippe Peter; Bruno Lopez; Lewis Thorne; Andrew McEvoy; Anna Miserocchi; George Samandouras; Neil Kitchen; Sebastian Brandner; Enrico De Vita; Francisco Torrealdea; Marilena Rega; Benjamin Schmitt; Patrick Liebig; Eser Sanverdi; Xavier Golay; Sotirios Bisdas Journal: Eur J Nucl Med Mol Imaging Date: 2022-01-14 Impact factor: 10.057
Authors: Benjamin Bender; Kai Herz; Anagha Deshmane; Vivien Richter; Ghazaleh Tabatabai; Jens Schittenhelm; Marco Skardelly; Klaus Scheffler; Ulrike Ernemann; Mina Kim; Xavier Golay; Moritz Zaiss; Tobias Lindig Journal: MAGMA Date: 2021-12-10 Impact factor: 2.310