title: DCD pigs' kidneys analyzed by MRI to assess ex vivo their viability.
abstract: BACKGROUND
  Magnetic resonance imaging (MRI) gadolinium-perfusion was applied in simulated Donation after Cardiac Death (DCD) in porcine kidneys to measure intrarenal perfusion. Adenosine triphosphate (ATP) resynthesis during oxygenated hypothermic perfusion was compared to evaluate the "ex vivo organ viability". Adenine nucleotide (AN) was measured by P nuclear magnetic resonance (NMR) spectroscopy. Whereas this latter technique requires sophisticated hardware, gadolinium-perfusion can be realized using any standard proton-MRI scanner. The aim of this work was to establish a correlation between the two methods.
  
  
  METHODS
  Twenty-two porcine kidneys presenting up to 90 min warm ischemia were perfused with oxygenation at 4 °C using our magnetic resonance-compatible machine. During the perfusion, P NMR spectroscopy and gadolinium-perfusion sequences were performed. Measures obtained from the gadolinium-perfusion were the speed of elimination of the cortical gadolinium and the presence or absence of a corticomedullar shunt. For ATP resynthesis analysis, P chemical shift imaging was acquired and analyzed. All the kidneys have been submitted to histologic examination.
  
  
  RESULTS
  ATP resynthesis was observed in all organs presenting a cortical gadolinium elimination slope of (-) 23° or greater. In organs with lower gadolinium elimination, no AN or only precursors were detected. This study reveals a link between the two methods and demonstrates ex vivo viability in 93% of the analyzed kidneys. Benefits and side effects of both methods are discussed.
  
  
  CONCLUSIONS
  Oxygenated hypothermic perfusion enables the evaluation of kidneys in DCD simulated situation; gadolinium-perfusion can be introduced into any center equipped with a proton-MRI scanner allowing results superposable with ATP measurement.
authors.affiliation: 1 Research and Development Laboratory, Visceral and Transplantation Service, University Hospital Geneva, Geneva, Switzerland. 2 Research Unit of Surgery, Visceral and Transplantation Service, University Hospital Geneva, Geneva, Switzerland. 3 Department of Pathology, University Hospital Geneva, Geneva, Switzerland. 4 Service of Radiology, University of Geneva, Geneva, Switzerland. 5 Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland. 6 Department of Radiology, University Hospital Geneva, Geneva, Switzerland. 7 Address correspondence to: Jean-Bernard Buchs, MD, Research and Development Laboratory, Visceral and Transplantation Service, University Hospital Geneva, Geneva, Switzerland.
authors.forename: Jean-Bernard
authors.initials: JB
authors.lastname: Buchs
authors.forename: Leo
authors.initials: L
authors.lastname: Buehler
authors.forename: Solange
authors.initials: S
authors.lastname: Moll
authors.forename: Raphael
authors.initials: R
authors.lastname: Ruttimann
authors.forename: Antonio
authors.initials: A
authors.lastname: Nastasi
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Kasten
authors.forename: Philippe
authors.initials: P
authors.lastname: Morel
authors.forename: François
authors.initials: F
authors.lastname: Lazeyras
mesh_terms: D000255:Adenosine Triphosphate / Q000096:biosynthesis; D000818:Animals; D005682:Gadolinium; D007668:Kidney / Q000098:blood supply* / Q000378:metabolism; D016030:Kidney Transplantation; D008279:Magnetic Resonance Imaging / Q000379:methods*; D013552:Swine; D014022:Tissue Survival
chemical_list: D000255:Adenosine Triphosphate; D005682:Gadolinium