title: Hyperpolarized 13C urea relaxation mechanism reveals renal changes in diabetic nephropathy.
abstract: OBJECTIVE
  Our aim was to assess a novel (13) C radial fast spin echo golden ratio single shot method for interrogating early renal changes in the diabetic kidney, using hyperpolarized (HP) [(13) C,(15) N2 ]urea as a T2 relaxation based contrast bio-probe.
  
  
  METHODS
  A novel HP (13) C MR contrast experiment was conducted in a group of streptozotocin type-1 diabetic rat model and age matched controls.
  
  
  RESULTS
  A significantly different relaxation time (P = 0.004) was found in the diabetic kidney (0.49 ± 0.03 s) compared with the controls (0.64 ± 0.02 s) and secondly, a strong correlation between the blood oxygen saturation level and the relaxation times were observed in the healthy controls.
  
  
  CONCLUSIONS
  HP [(13) C,(15) N2 ]urea apparent T2 mapping may be a useful for interrogating local renal pO2 status and renal tissue alterations. Magn Reson Med, 2015. © 2015 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
authors.affiliation: MR Research Centre, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
authors.forename: Christoffer
authors.initials: C
authors.lastname: Laustsen
authors.affiliation: MR Research Centre, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
authors.forename: Thomas
authors.initials: T
authors.lastname: Stokholm Nørlinger
authors.affiliation: MR Research Centre, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
authors.forename: David
authors.initials: D
authors.lastname: Christoffer Hansen
authors.affiliation: MR Research Centre, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
authors.forename: Haiyun
authors.initials: H
authors.lastname: Qi
authors.affiliation: MR Research Centre, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
authors.forename: Per
authors.initials: P
authors.lastname: Mose Nielsen
authors.affiliation: MR Research Centre, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
authors.forename: Lotte
authors.initials: L
authors.lastname: Bonde Bertelsen
authors.affiliation: GE Healthcare, Broendby, Denmark.|Department of Electrical Engineering, Technical University of Denmark, Kgs Lyngby, Denmark.
authors.forename: Jan
authors.initials: J
authors.lastname: Henrik Ardenkjaer-Larsen
authors.affiliation: MR Research Centre, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
authors.forename: Hans
authors.initials: H
authors.lastname: Stødkilde Jørgensen
mesh_terms: D000818:Animals; D002247:Carbon Isotopes / Q000737:chemistry; D003928:Diabetic Nephropathies / Q000378:metabolism* / Q000473:pathology*; D005260:Female; D007091:Image Processing, Computer-Assisted; D007668:Kidney / Q000378:metabolism* / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010100:Oxygen / Q000097:blood; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D014508:Urea / Q000737:chemistry*
chemical_list: D002247:Carbon Isotopes; D014508:Urea; D010100:Oxygen
keywords: MRI; hyperpolarization; kidney; renal metabolism; type 1 diabetes