Grzegorz L Chadzynski1,2, Jonas Bause2,3, Gunamony Shajan2, Rolf Pohmann2, Klaus Scheffler1,2, Philipp Ehses1,2. 1. Department of Biomedical Magnetic Resonance, Eberhard-Karls University of Tübingen, Tübingen, Germany. 2. High-field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany. 3. Graduate Training Centre of Neuroscience, Eberhard-Karls University of Tübingen, Tübingen, Germany.
Abstract
PURPOSE: The purpose of this work was to develop a fast and efficient MRSI-FID acquisition scheme and test its performance in vivo. The aim was to find a trade-off between the minimal total acquisition time and signal-to-noise ratio of the acquired spectra. METHODS: Measurements were performed on a 9.4 Tesla system. Sequence optimization included redesign of water suppression, optimization of the sequence gradients, and improvement of the sampling efficiency by minimizing the read-out time. This resulted in an acquisition time of 2:47 and 22:13 minutes for 2D (TR = 57 ms; 3-mm in-plane resolution) and 3D MRSI (TR = 57 ms; 16 slices; 3-mm isotropic resolution), respectively. RESULTS: Despite strong T1 weighting and first-order phase problems, it was possible to obtain spectra of an acceptable quality. The average line width calculated for the tCr peak across the entire field of view was 26.9 ± 9.6 Hz for 2D and 30.0 ± 11.3 Hz for 3D MRSI. In 3D measurements, the percent fraction of voxels fitted with Cramer-Rao lower bounds below 10% was 53.3 ± 4.1%, 63.4 ± 8.4%, and 81.0 ± 2.9% for Glu, tCr, and tNAA, respectively. CONCLUSION: Considering the typically long duration of high-resolution MRSI, the proposed technique may be of interest for clinical applications and/or studies that focus on following the biochemistry of dynamic processes. Magn Reson Med 78:1281-1295, 2017.
PURPOSE: The purpose of this work was to develop a fast and efficient MRSI-FID acquisition scheme and test its performance in vivo. The aim was to find a trade-off between the minimal total acquisition time and signal-to-noise ratio of the acquired spectra. METHODS: Measurements were performed on a 9.4 Tesla system. Sequence optimization included redesign of water suppression, optimization of the sequence gradients, and improvement of the sampling efficiency by minimizing the read-out time. This resulted in an acquisition time of 2:47 and 22:13 minutes for 2D (TR = 57 ms; 3-mm in-plane resolution) and 3D MRSI (TR = 57 ms; 16 slices; 3-mm isotropic resolution), respectively. RESULTS: Despite strong T1 weighting and first-order phase problems, it was possible to obtain spectra of an acceptable quality. The average line width calculated for the tCr peak across the entire field of view was 26.9 ± 9.6 Hz for 2D and 30.0 ± 11.3 Hz for 3D MRSI. In 3D measurements, the percent fraction of voxels fitted with Cramer-Rao lower bounds below 10% was 53.3 ± 4.1%, 63.4 ± 8.4%, and 81.0 ± 2.9% for Glu, tCr, and tNAA, respectively. CONCLUSION: Considering the typically long duration of high-resolution MRSI, the proposed technique may be of interest for clinical applications and/or studies that focus on following the biochemistry of dynamic processes. Magn Reson Med 78:1281-1295, 2017.
Authors: Michal Považan; Bernhard Strasser; Gilbert Hangel; Eva Heckova; Stephan Gruber; Siegfried Trattnig; Wolfgang Bogner Journal: Magn Reson Med Date: 2017-06-22 Impact factor: 4.668
Authors: Philipp Moser; Wolfgang Bogner; Lukas Hingerl; Eva Heckova; Gilbert Hangel; Stanislav Motyka; Siegfried Trattnig; Bernhard Strasser Journal: Magn Reson Med Date: 2019-06-10 Impact factor: 4.668
Authors: Eva Heckova; Michal Považan; Bernhard Strasser; Stanislav Motyka; Gilbert Hangel; Lukas Hingerl; Philipp Moser; Alexandra Lipka; Stephan Gruber; Siegfried Trattnig; Wolfgang Bogner Journal: Magn Reson Med Date: 2019-08-08 Impact factor: 4.668