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@ARTICLE{Gast:298950,
      author       = {L. V. Gast and T. Gerhalter and M. Türk and A. Sapli and
                      C. S. Mathy and R. Heiss and P.-Y. Baudin and B. Marty and
                      M. Uder and A. Nagel$^*$},
      title        = {{D}etermination of {T}issue {P}otassium and {S}odium
                      {C}oncentrations in {D}ystrophic {S}keletal {M}uscle
                      {T}issue {U}sing {C}ombined {P}otassium (39{K}) and {S}odium
                      (23{N}a) {MRI} at 7 {T}.},
      journal      = {NMR in biomedicine},
      volume       = {38},
      number       = {4},
      issn         = {0952-3480},
      address      = {New York, NY},
      publisher    = {Wiley},
      reportid     = {DKFZ-2025-00384},
      pages        = {e70009},
      year         = {2025},
      note         = {#LA:E020#},
      abstract     = {Combined 23Na/39K MRI at 7 T can highlight ion disturbances
                      in skeletal muscle tissue. In this work, we investigated if
                      the apparent tissue potassium concentration (aTPC) can be
                      determined in fatty replaced muscles of patients with
                      facio-scapulo-humeral muscular dystrophy (FSHD) and if it
                      can provide additional information to the fat replacement
                      and the apparent tissue sodium concentration (aTSC). The
                      lower leg of 14 patients (six females, eight males; mean age
                      47.7 ± 14.0 years) with genetically confirmed FSHD and 11
                      healthy controls (four females, seven males; mean age 47.0
                      ± 14.0 years) was examined at a 7-T MR system using a
                      dual-tuned 23Na/39K birdcage RF coil. In addition,
                      qualitative and quantitative 1H MR measurements were
                      performed at 7 T to assess the fat replacement and water
                      accumulation. The aTPC and aTSC were determined in seven
                      different muscle regions based on five external references
                      phantoms and corrected for partial volume effects,
                      relaxation biases, and reduced ion concentrations in fat.
                      Results are expressed as median (interquartile range). The
                      measured aTPC was strongly reduced in fat-replaced muscles
                      and was close to zero in totally fat replaced muscles (aTPC
                      = 4.3 mM [2.7 mM] for FF > $80\%).$ After correction of aTPC
                      values for reduced potassium concentration in fat, aTPCfc
                      values of patients in muscles with low or moderate fat
                      fraction (FF < $30\%)$ were similar to values of healthy
                      subjects (patients: aTPCfc = 85.6 mM [21.7 mM]; controls:
                      aTPCfc = 83.2 mM [22.3 mM]). However, muscles with FF >
                      $30\%$ showed reduced aTPCfc and increased aTSCfc compared
                      with healthy controls (aTPCfc = 28.9 mM [46.2 mM], aTSCfc =
                      42.3 mM [17.6 mM]; controls: aTSCfc = 15.0 mM [4.6 mM],
                      aTPCfc = 83.2 mM [22.3 mM]). No correlations were observed
                      between the aTPCfc and aTSCfc, or between aTPCfc and water
                      T2. We showed that a determination of the aTPC in dystrophic
                      skeletal muscles is feasible using 39K MRI at 7 T. Measured
                      changes in aTPCfc were greater than sole fat replacement and
                      might therefore be used as an additional quantitative
                      measure for dystrophic muscle tissue.},
      keywords     = {Humans / Male / Female / Magnetic Resonance Imaging /
                      Sodium: metabolism / Muscle, Skeletal: diagnostic imaging /
                      Muscle, Skeletal: metabolism / Middle Aged / Potassium /
                      Adult / Phantoms, Imaging / Sodium Isotopes / 7 T (Other)
                      / facio‐scapulo‐humeral muscular dystrophy (Other) /
                      potassium MRI (Other) / skeletal muscle (Other) / sodium MRI
                      (Other) / ultrahigh field strength (Other) / Sodium (NLM
                      Chemicals) / Potassium (NLM Chemicals) / Sodium Isotopes
                      (NLM Chemicals)},
      cin          = {E020},
      ddc          = {610},
      cid          = {I:(DE-He78)E020-20160331},
      pnm          = {315 - Bildgebung und Radioonkologie (POF4-315)},
      pid          = {G:(DE-HGF)POF4-315},
      typ          = {PUB:(DE-HGF)16},
      pubmed       = {pmid:39962713},
      doi          = {10.1002/nbm.70009},
      url          = {https://inrepo02.dkfz.de/record/298950},
}