title: Dynamic Contrast-Enhanced Computed Tomography: A New Diagnostic Tool to Assess Renal Perfusion After Ischemia-Reperfusion Injury in Mice: Correlation of Perfusion Deficit to Histopathologic Damage.
abstract: OBJECTIVE
  The aim of this study was to investigate the value of dynamic contrast-enhanced computed tomography (CT) in the assessment of renal perfusion parameters after ischemia-reperfusion (I/R) injury in an experimental murine model.
  
  
  METHODS
  Balb/cJ wildtype mice were subjected to 45 minutes (AKI45) or 60 minutes (AKI60) of unilateral warm I/R injury by clamping the pedicle of the right kidney. Two, 7, and 18 days after right I/R injury, renal blood flow (RBF), renal volume of distribution (RVD), and mean transit time were quantitatively assessed in the cortex of both kidneys by dynamic contrast-enhanced CT. Acute tubular injury (ATI) was assessed by histologic analysis using a semiquantitative sum score (score, 0-18) and correlated with RBF, RVD, and mean transit time.
  
  
  RESULTS
  Histologic signs of ATI could be detected in the clamped kidneys in both groups already at day 2. Pathologic features of ATI worsened in AKI60 until day 18 (score, 7 ± 0), whereas mice in AKI45 group showed amelioration over time (score, 4 ± 2). Renal blood flow was significantly reduced in ischemic kidneys in AKI45 (287 ± 32 mL/100 mL per minute; P < 0.01) and AKI60 group (249 ± 73 mL/100 mL per minute; P < 0.01) as compared with that in healthy kidneys (402 ± 49 mL/100 mL per minute) on day 2. It decreased further at day 7 in both groups (AKI45: 165 ± 44 mL/100 mL per minute, P < 0.01; AKI60: 151 ± 72 mL/100 mL per minute, P < 0.05) and improved at day 18 in AKI45 (261 ± 11 mL/100 mL per minute, P < 0.05) and to a lesser degree in AKI60 (197 ± 52 mL/100 mL per minute, P > 0.05). Values of RVD paralleled RBF at all time points. Renal blood flow (r = -0.79; P < 0.01) and RVD (r = -0.8; P < 0.01) significantly correlated with the histological damage score (Spearman rank correlation).
  
  
  CONCLUSIONS
  Dynamic contrast-enhanced CT is a noninvasive method to determine renal perfusion changes in acute kidney injury. It might be a valuable diagnostic tool to predict outcome or monitor treatment effects of renal I/R injury.
authors.affiliation: From the *Institute of Clinical Radiology, and †Transplant Center Munich, Ludwig-Maximilians-University Hospital Munich, Munich, Germany; ‡Department of Pathology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom; and §Department of Radiology, University Hospital Tübingen, Tübingen, Germany.
authors.forename: Margarita
authors.initials: M
authors.lastname: Braunagel
authors.forename: Andreas
authors.initials: A
authors.lastname: Helck
authors.forename: Anne
authors.initials: A
authors.lastname: Wagner
authors.forename: Nina
authors.initials: N
authors.lastname: Schupp
authors.forename: Verena
authors.initials: V
authors.lastname: Bröcker
authors.forename: Maximilian
authors.initials: M
authors.lastname: Reiser
authors.forename: Mike
authors.initials: M
authors.lastname: Notohamiprodjo
authors.forename: Bruno
authors.initials: B
authors.lastname: Meiser
authors.forename: Antje
authors.initials: A
authors.lastname: Habicht
mesh_terms: D058186:Acute Kidney Injury / Q000000981:diagnostic imaging* / Q000473:pathology; D000818:Animals; D004195:Disease Models, Animal; D007668:Kidney / Q000098:blood supply* / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D012079:Renal Circulation; D015427:Reperfusion Injury / Q000000981:diagnostic imaging* / Q000473:pathology; D014057:Tomography, X-Ray Computed / Q000379:methods*