title: T1-mapping for assessment of ischemia-induced acute kidney injury and prediction of chronic kidney disease in mice.
abstract: OBJECTIVE
  To investigate whether T1-mapping allows assessment of acute kidney injury (AKI) and prediction of chronic kidney disease (CKD) in mice.
  
  
  METHODS
  AKI was induced in C57Bl/6N mice by clamping of the right renal pedicle for 35 min (moderate AKI, n = 26) or 45 min (severe AKI, n = 23). Sham animals served as controls (n = 9). Renal histology was assessed in the acute (day 1 + day 7; d1 + d7) and chronic phase (d28) after AKI. Furthermore, longitudinal MRI-examinations (prior to until d28 after surgery) were performed using a 7-Tesla magnet. T1-maps were calculated from a fat-saturated echoplanar inversion recovery sequence, and mean and relative T1-relaxation times were determined.
  
  
  RESULTS
  Renal histology showed severe tubular injury at d1 + d7 in both AKI groups, whereas, at d28, only animals with prolonged 45-min ischemia showed persistent signs of AKI. Following both AKI severities T1-values significantly increased and peaked at d7. T1-times in the contralateral kidney without AKI remained stable. At d7 relative T1-values in the outer stripe of the outer medulla were significantly higher after severe than after moderate AKI (138 ± 2% vs. 121 ± 3%, p = 0.001). T1-elevation persisted until d28 only after severe AKI. Already at d7 T1 in the outer stripe of the outer medulla correlated with kidney volume loss indicating CKD (r = 0.83).
  
  
  CONCLUSIONS
  T1-mapping non-invasively detects AKI severity in mice and predicts further outcome.
  
  
  CONCLUSIONS
  Renal T1-relaxation times are increased after ischemia-induced acute kidney injury. Renal T1-values correlate with subsequent kidney volume loss. T1-mapping detects the severity of acute kidney injury and predicts further outcome.
authors.affiliation: Department of Radiology, Hannover Medical School, Carl-Neuberg-Str.1, 30625, Hannover, Germany, hueper.katja@mh-hannover.de.
authors.forename: Katja
authors.initials: K
authors.lastname: Hueper
authors.forename: Matti
authors.initials: M
authors.lastname: Peperhove
authors.forename: Song
authors.initials: S
authors.lastname: Rong
authors.forename: Jessica
authors.initials: J
authors.lastname: Gerstenberg
authors.forename: Michael
authors.initials: M
authors.lastname: Mengel
authors.forename: Martin
authors.initials: M
authors.lastname: Meier
authors.forename: Marcel
authors.initials: M
authors.lastname: Gutberlet
authors.forename: Susanne
authors.initials: S
authors.lastname: Tewes
authors.forename: Amelie
authors.initials: A
authors.lastname: Barrmeyer
authors.forename: Rongjun
authors.initials: R
authors.lastname: Chen
authors.forename: Herman
authors.initials: H
authors.lastname: Haller
authors.forename: Frank
authors.initials: F
authors.lastname: Wacker
authors.forename: Dagmar
authors.initials: D
authors.lastname: Hartung
authors.forename: Faikah
authors.initials: F
authors.lastname: Gueler
mesh_terms: D058186:Acute Kidney Injury / Q000150:complications / Q000175:diagnosis*; D000818:Animals; D004195:Disease Models, Animal; D007668:Kidney / Q000098:blood supply / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011237:Predictive Value of Tests; D051436:Renal Insufficiency, Chronic / Q000175:diagnosis / Q000209:etiology*; D015427:Reperfusion Injury / Q000150:complications* / Q000175:diagnosis