Assessing muscle-specific potassium concentrations in human lower leg using potassium magnetic resonance imaging

Gast L, Baier LM, Chaudry O, Meixner C, Müller M, Engelke K, Uder M, Heiß R, Nagel AM (2022)

Publication Type: Journal article

Publication year: 2022

Journal

Abstract

Noninvasively assessing tissue potassium concentrations (TPCs) using potassium magnetic resonance imaging (³⁹K MRI) could give valuable information on physiological processes connected to various pathologies. However, because of inherently low ³⁹K MR image resolution and strong signal blurring, a reliable measurement of the TPC is challenging. The aim of this work was to investigate the feasibility of a muscle-specific TPC determination with a focus on the influence of a varying residual quadrupolar interaction in human lower leg muscles. The quantification accuracy of a muscle-specific TPC determination was first assessed using simulated ³⁹K MRI data. In vivo ³⁹K and corresponding sodium (²³Na) MRI data of healthy lower leg muscles (n = 14, seven females) were acquired on a 7-T MR system using a double-resonant ²³Na/³⁹K birdcage Tx/Rx RF coil. Additional ¹H MR images were acquired on a 3-T MR system and used for tissue segmentation. Quantification of TPC was performed after a region-based partial volume correction (PVC) using five external reference phantoms. Simulations not only underlined the importance of PVC for correctly assessing muscle-specific TPC values, but also revealed the strong impact of a varying residual quadrupolar interaction between different muscle regions on the measured TPC. Using ³⁹K T2^* decay curves, we found significantly higher residual quadrupolar interaction in tibialis anterior muscle (TA; ωq = 194 ± 28 Hz) compared with gastrocnemius muscle (medial/lateral head, GM/GL; ωq = 151 ± 25 Hz) and soleus muscle (SOL; ωq = 102 ± 32 Hz). If considered in the PVC, TPC in individual muscles was similar (TPC = 98 ± 11/96 ± 14/99 ± 8/100 ± 12 mM in GM/GL/SOL/TA). Comparison with tissue sodium concentrations suggested that residual quadrupolar interactions might also influence the ²³Na MRI signal of lower leg muscles. A TPC determination of individual lower leg muscles is feasible and can therefore be applied in future studies. Considering a varying residual quadrupolar interaction for PVC of ³⁹K MRI data is essential to reliably assess potassium concentrations in individual muscles.

Authors with CRIS profile

Lena Gast Institute of Radiology Oliver Chaudry Department of Medicine 3 – Rheumatology and Immunology Christian Meixner Institute of Radiology Max Müller Institute of Radiology Klaus Engelke Medizinische Fakultät Michael Uder Lehrstuhl für Diagnostische Radiologie Rafael Heiß Institute of Radiology Armin Michael Nagel Professur für metabolische und funktionelle MR-Bildgebung

How to cite

APA:

Gast, L., Baier, L.-M., Chaudry, O., Meixner, C., Müller, M., Engelke, K.,... Nagel, A.M. (2022). Assessing muscle-specific potassium concentrations in human lower leg using potassium magnetic resonance imaging. NMR in Biomedicine. https://doi.org/10.1002/nbm.4819

MLA:

Gast, Lena, et al. "Assessing muscle-specific potassium concentrations in human lower leg using potassium magnetic resonance imaging." NMR in Biomedicine (2022).

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