Improved Myocardial Sodium Quantification at 7 T Using Interleaved 23Na/1H pTx MRI With Motion and Anatomy-Based B1 Correction

Ruck L, Egger N, Zobler B, Schirmer J, Nagelstraßer S, Bitz A, Platt T, Konstandin S, Kopp C, Uder M, Nagel AM (2026)

Publication Type: Journal article

Publication year: 2026

Journal

Magnetic Resonance in Medicine Wiley

DOI: 10.1002/mrm.70342

Abstract

Purpose: To improve accuracy and repeatability of myocardial 23Na quantification in cardiac MRI at 7 T by combining retrospective respiratory and cardiac motion correction with a novel anatomy-based B1 bias field correction. Methods: In this study, a dual-nuclear interleaved 23Na/1H MRI sequence at 7 T was applied. Here, 1H MR data enabled automated segmentation of myocardium and blood pool via nnUNet and facilitated respiratory and cardiac motion correction for both contrasts using 1H navigators. For 23Na MRI, a novel anatomy-based B1 bias field correction was developed, estimating the transmit and receive (B1) field bias from 1H-derived segmentations and synthetic 23Na images. All correction methods were validated through realistic simulations and in vivo studies. Repeatability was assessed in 10 healthy subjects, and the proposed B1 correction was compared to phantom-based methods. Results: Respiratory and cardiac motion correction reduced quantification errors and improved SNR compared to conventional gating. The anatomy-based B1 correction effectively mitigated errors caused by B1 inhomogeneities and outperformed phantom-based methods in terms of repeatability. The measured apparent tissue sodium concentration of the myocardium after all corrections (49.5 (Formula presented.) 4.7 mM) was consistent with literature values. Combined motion and B1 corrections improved repeatability, reducing the coefficient of repeatability from 4.9 mM (11.2%) without corrections to 2.0 mM (4.0%) after corrections. Conclusion: The combination of retrospective motion correction and anatomy-based B1 bias field correction enables repeatable myocardial sodium quantification at 7 T. The interleaved acquisition facilitates robust segmentation and efficient use of 1H MRI for motion and B1 correction, providing a scalable framework for future clinical research studies.

Authors with CRIS profile

Laurent Ruck Institute of Radiology Nico Egger Institute of Radiology Benedikt Zobler Department of Medicine 4 – Nephrology and Hypertension Judith Schirmer Institute of Radiology Sophia Nagelstraßer Institute of Radiology Christoph Kopp Department of Medicine 4 – Nephrology and Hypertension Michael Uder Lehrstuhl für Diagnostische Radiologie Armin Michael Nagel Institute of Radiology

Involved external institutions

Deutsches Krebsforschungszentrum (DKFZ) DE Germany (DE) Fraunhofer-Institut für Bildgestützte Medizin (MEVIS) DE Germany (DE) Fachhochschule Aachen - Aachen University of Applied Sciences DE Germany (DE)

How to cite

APA:

Ruck, L., Egger, N., Zobler, B., Schirmer, J., Nagelstraßer, S., Bitz, A.,... Nagel, A.M. (2026). Improved Myocardial Sodium Quantification at 7 T Using Interleaved 23Na/1H pTx MRI With Motion and Anatomy-Based B1 Correction. Magnetic Resonance in Medicine. https://doi.org/10.1002/mrm.70342

MLA:

Ruck, Laurent, et al. "Improved Myocardial Sodium Quantification at 7 T Using Interleaved 23Na/1H pTx MRI With Motion and Anatomy-Based B1 Correction." Magnetic Resonance in Medicine (2026).

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