% IMPORTANT: The following is UTF-8 encoded.  This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.

@ARTICLE{Franke:287629,
      author       = {V. Franke$^*$ and J. Breitling$^*$ and P. Boyd$^*$ and A.
                      Feignier$^*$ and R. Bangert$^*$ and N. Weckesser$^*$ and
                      H.-P. Schlemmer$^*$ and M. Ladd$^*$ and P. Bachert$^*$ and
                      D. Paech$^*$ and A. Korzowski$^*$},
      title        = {{A} versatile look-up algorithm for mapping p{H} values and
                      magnesium ion content using 31 {P} {MRSI}.},
      journal      = {NMR in biomedicine},
      volume       = {37},
      number       = {6},
      issn         = {0952-3480},
      address      = {New York, NY},
      publisher    = {Wiley},
      reportid     = {DKFZ-2024-00283},
      pages        = {e5113},
      year         = {2024},
      note         = {2024 Jun;37(6):e5113 / #EA:E020#LA:E020#},
      abstract     = {31 P MRSI allows for the non-invasive mapping of pH and
                      magnesium ion content (Mg) in vivo, by translating the
                      chemical shifts of inorganic phosphate and
                      adenosine-5'-triphosphate (ATP) to pH and Mg via suitable
                      calibration equations, such as the modified
                      Henderson-Hasselbalch equation. However, the required
                      constants in these calibration equations are typically only
                      determined for physiological conditions, posing a particular
                      challenge for their application to diseased tissue, where
                      the biochemical conditions might change manyfold. In this
                      article, we propose a multi-parametric look-up algorithm
                      aiming at the condition-independent determination of pH and
                      Mg by employing multiple quantifiable 31 P spectral
                      properties simultaneously. To generate entries for an
                      initial look-up table, measurements from 114 model solutions
                      prepared with varying chemical properties were made at 9.4
                      T. The number of look-up table entries was increased by
                      inter- and extrapolation using a multi-dimensional function
                      developed based on the Hill equation. The assignment of
                      biochemical parameters, that is, pH and Mg, is realized
                      using probability distributions incorporating specific
                      measurement uncertainties on the quantified spectral
                      parameters, allowing for an estimation of most plausible
                      output values. As proof of concept, we applied a version of
                      the look-up algorithm employing only the chemical shifts of
                      γ- and β-ATP for the determination of pH and Mg to in vivo
                      3D 31 P MRSI data acquired at 7 T from (i) the lower leg
                      muscles of healthy volunteers and (ii) the brains of
                      patients with glioblastoma. The resulting volumetric maps
                      showed plausible values for pH and Mg, partly revealing
                      differences from maps generated using the conventional
                      calibration equations.},
      keywords     = {31P MRS (Other) / 31P MRSI (Other) / magnesium (Other) /
                      magnesium ion concentration (Other) / pH (Other) / pH
                      imaging (Other)},
      cin          = {E020 / E010},
      ddc          = {610},
      cid          = {I:(DE-He78)E020-20160331 / I:(DE-He78)E010-20160331},
      pnm          = {315 - Bildgebung und Radioonkologie (POF4-315)},
      pid          = {G:(DE-HGF)POF4-315},
      typ          = {PUB:(DE-HGF)16},
      pubmed       = {pmid:38316107},
      doi          = {10.1002/nbm.5113},
      url          = {https://inrepo02.dkfz.de/record/287629},
}