Johanna Lott1,2, Tanja Platt1, Sebastian C Niesporek1, Daniel Paech3, Nicolas G R Behl1, Thoralf Niendorf4,5, Peter Bachert1,2, Mark E Ladd1,2,6, Armin M Nagel1,7,8. 1. German Cancer Research Center (DKFZ), Medical Physics in Radiology, Heidelberg, Germany. 2. University of Heidelberg, Faculty of Physics and Astronomy, Heidelberg, Germany. 3. German Cancer Research Center (DKFZ), Radiology, Heidelberg, Germany. 4. Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany. 5. MRI. TOOLS GmbH, Berlin, Germany. 6. University of Heidelberg, Faculty of Medicine, Heidelberg, Germany. 7. Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), University Hospital Erlangen, Institute of Radiology, Erlangen, Germany. 8. Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Institute of Medical Physics, Erlangen, Germany.
Abstract
PURPOSE: To quantify the tissue sodium concentration (TSC) in cardiac 23 Na MRI. To evaluate the influence of different correction methods on the measured myocardial TSC. METHODS: 23 Na MRI of four healthy subjects was conducted at a whole-body 7T MRI system using an oval-shaped 23 Na birdcage coil. Data acquisition was performed with a density-adapted 3D radial pulse sequence using a golden angle projection scheme. 1 H MRI data were acquired at a 3T MRI system to generate a myocardial mask. Retrospective cardiac and respiratory gating were used to reconstruct 23 Na MRI data in the diastolic phase and exhaled state. B0 and B1 inhomogeneity and partial volume (PV) effects were corrected. Relaxation times and TSC of ex vivo blood samples and calf muscle were determined. These values were used in the PV correction to estimate myocardial TSC, which was compared with the measured TSC of calf muscle. RESULTS: Without any correction the measured myocardial TSC was (54 ± 5) mM. The applied correction methods reduced these values by (48 ± 5)% to (29 ± 3) mM, where PV correction had the largest effect (reduction of (34 ± 1)%). Respiratory and cardiac motion gating decreased the concentrations by (11 ± 1)%. With the applied setup, the corrections of B0 and B1 inhomogeneity (reduction of (3 ± 2)%) had negligible influences on TSC values. The resulting myocardial TSC was approximately 1.4-fold higher than the measured TSC of calf muscle tissue of the same healthy subjects ((20 ± 3) mM). CONCLUSION: For quantitative human cardiac 23 Na MRI several corrections are needed and ranked for our setup: PV correction, respiratory and cardiac gating, correction for B1 inhomogeneity effects.
PURPOSE: To quantify the tissue sodium concentration (TSC) in cardiac 23 Na MRI. To evaluate the influence of different correction methods on the measured myocardial TSC. METHODS: 23 Na MRI of four healthy subjects was conducted at a whole-body 7T MRI system using an oval-shaped 23 Na birdcage coil. Data acquisition was performed with a density-adapted 3D radial pulse sequence using a golden angle projection scheme. 1 H MRI data were acquired at a 3T MRI system to generate a myocardial mask. Retrospective cardiac and respiratory gating were used to reconstruct 23 Na MRI data in the diastolic phase and exhaled state. B0 and B1 inhomogeneity and partial volume (PV) effects were corrected. Relaxation times and TSC of ex vivo blood samples and calf muscle were determined. These values were used in the PV correction to estimate myocardial TSC, which was compared with the measured TSC of calf muscle. RESULTS: Without any correction the measured myocardial TSC was (54 ± 5) mM. The applied correction methods reduced these values by (48 ± 5)% to (29 ± 3) mM, where PV correction had the largest effect (reduction of (34 ± 1)%). Respiratory and cardiac motion gating decreased the concentrations by (11 ± 1)%. With the applied setup, the corrections of B0 and B1 inhomogeneity (reduction of (3 ± 2)%) had negligible influences on TSC values. The resulting myocardial TSC was approximately 1.4-fold higher than the measured TSC of calf muscle tissue of the same healthy subjects ((20 ± 3) mM). CONCLUSION: For quantitative human cardiac 23 Na MRI several corrections are needed and ranked for our setup: PV correction, respiratory and cardiac gating, correction for B1 inhomogeneity effects.
Authors: Olgica Zaric; Hannes Beiglböck; Veronika Janacova; Pavol Szomolanyi; Peter Wolf; Michael Krebs; Siegfried Trattnig; Martin Krššák; Vladimir Juras Journal: BMC Musculoskelet Disord Date: 2022-10-20 Impact factor: 2.562
Authors: Martin Christa; Stefanie Hahner; Herbert Köstler; Wolfgang Rudolf Bauer; Stefan Störk; Andreas Max Weng Journal: Eur J Endocrinol Date: 2022-03-29 Impact factor: 6.558