Non-invasive determination of metabolite concentrations in human transplanted kidney in vivo by 31P MR spectroscopy.
OBJECTIVE
To investigate concentrations of phosphorus-containing metabolites in human transplanted kidney in vivo by quantitative 31P MR spectroscopy (MRS) using surface coils and to compare the obtained values with previous data.


METHODS
In 5 patients with well-functioning transplanted kidneys, 31P spectra were obtained with the three-dimensional localization image-selected in vivo spectroscopy technique applying a protocol for quantitative spectroscopy using surface coils. Relaxation corrected signal intensities determined by time domain fitting were used to derive absolute molar concentrations for phosphate-containing metabolites.


RESULTS
Little or no phosphocreatine in all spectra verified the absence of muscle contamination, confirming proper volume localization. The mean concentrations in the transplanted kidneys were as follows: ATP 1.60 +/- 0.26 mmol/ 1, PDE 2.14 +/- 0.91 mmol/l, Pi 0.66 +/- 0.25 mmol/l, PME 2.32+ /- 0.50 mmol/l. These values are consistent with previously reported values determined by other techniques.


CONCLUSIONS
The non-invasive determination of absolute metabolite concentrations in human kidney using MRS supplements the use of signal intensity ratios to detect pathologic changes in the energy metabolism of transplanted kidneys.
Kugel
H
H
Department of Diagnostic Radiology, University of Cologne, Germany.
Wittsack H-J
Wenzel
F
F
Stippel
D
D
Heindel
W
W
Lackner
K
K
D000255:Adenosine Triphosphate / Q000032:analysis; D000328:Adult; D006801:Humans; D007668:Kidney / Q000737:chemistry*; D016030:Kidney Transplantation; D009682:Magnetic Resonance Spectroscopy; D008875:Middle Aged; D010725:Phosphocreatine / Q000032:analysis; D010758:Phosphorus / Q000032:analysis
D010725:Phosphocreatine; D010758:Phosphorus; D000255:Adenosine Triphosphate