Maximilian Fuetterer1, Christian T Stoeck1,2, Sebastian Kozerke1,2. 1. Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland. 2. Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK.
Abstract
PURPOSE: Second-order motion compensation for point-resolved spectroscopy (PRESS) is proposed to allow for robust single-voxel cardiac spectroscopy throughout the entire cardiac cycle and at various heart rates. METHODS: Bipolar FID spoiling gradient pairs compensating for first and second-order motion were designed and implemented into a cardiac-triggered PRESS sequence on a clinical MR system. A numerical three-dimensional model of cardiac motion was used to optimize and validate the gradient waveforms. In vivo measurements in healthy volunteers were obtained to assess the signal-to-noise ratio (SNR) and triglyceride-to-water ratio (TG/W). SNR gains and variability of TG/W of the proposed approach were evaluated against a conventional PRESS sequence with optimized gradients. RESULTS: The proposed sequence increases the mean SNR by 32% (W) and 23% (TG) on average with significantly lower variability for different trigger delays. The variability of TG/W quantification over the cardiac cycle is significantly decreased with second-order motion compensated PRESS when compared with conventional PRESS with reduced-spoiler gradients (coefficient of variation: 0.1 ± 0.02 versus 0.37 ± 0.26). CONCLUSION: Second-order motion compensated PRESS effectively reduces cardiac motion-induced signal degradation during FID spoiling, providing higher SNR and less variability for TG/W quantification. The sequence is considered promising to assess the TG/W modulation during various interventions including pharmacologically induced stress. Magn Reson Med 77:57-64, 2017.
PURPOSE: Second-order motion compensation for point-resolved spectroscopy (PRESS) is proposed to allow for robust single-voxel cardiac spectroscopy throughout the entire cardiac cycle and at various heart rates. METHODS: Bipolar FID spoiling gradient pairs compensating for first and second-order motion were designed and implemented into a cardiac-triggered PRESS sequence on a clinical MR system. A numerical three-dimensional model of cardiac motion was used to optimize and validate the gradient waveforms. In vivo measurements in healthy volunteers were obtained to assess the signal-to-noise ratio (SNR) and triglyceride-to-water ratio (TG/W). SNR gains and variability of TG/W of the proposed approach were evaluated against a conventional PRESS sequence with optimized gradients. RESULTS: The proposed sequence increases the mean SNR by 32% (W) and 23% (TG) on average with significantly lower variability for different trigger delays. The variability of TG/W quantification over the cardiac cycle is significantly decreased with second-order motion compensated PRESS when compared with conventional PRESS with reduced-spoiler gradients (coefficient of variation: 0.1 ± 0.02 versus 0.37 ± 0.26). CONCLUSION: Second-order motion compensated PRESS effectively reduces cardiac motion-induced signal degradation during FID spoiling, providing higher SNR and less variability for TG/W quantification. The sequence is considered promising to assess the TG/W modulation during various interventions including pharmacologically induced stress. Magn Reson Med 77:57-64, 2017.
Authors: Mareike Gastl; Sophie M Peereboom; Maximilian Fuetterer; Florian Boenner; Malte Kelm; Robert Manka; Sebastian Kozerke Journal: MAGMA Date: 2018-10-30 Impact factor: 2.310
Authors: Mareike Gastl; Sophie M Peereboom; Alexander Gotschy; Maximilian Fuetterer; Constantin von Deuster; Florian Boenner; Malte Kelm; Rahel Schwotzer; Andreas J Flammer; Robert Manka; Sebastian Kozerke Journal: J Cardiovasc Magn Reson Date: 2019-01-31 Impact factor: 5.364