title: Placental perfusion in uterine ischemia model as evaluated by dynamic contrast enhanced MRI.
abstract: BACKGROUND
  To validate DCE MRI method of placental perfusion estimation and to demonstrate application of the method in a rabbit model of fetal antenatal hypoxia-ischemia.
  
  
  METHODS
  Placental perfusion was estimated by dynamic contrast imaging with bolus injection of Gd-DTPA in 3 Tesla GE magnet in a rabbit model of placental ischemia-reperfusion in rabbit dams at embryonic day 25 gestation age. Placental perfusion was measured using steepest slope method on DCE MRI before and after intermittent 40 min uterine ischemia. Antioxidants (n = 2 dams, 9 placentas imaged) or vehicle (n = 5 dams, 23 placenta imaged) were given systemically in a separate group of dams during reperfusion-reoxygenation. Placental perfusion was also measured in two dams from the antioxidant group (10 placentas) and two dams from the control group (12 placentas) by fluorescent microspheres method.
  
  
  RESULTS
  While placental perfusion estimates between fluorescent microspheres and DCE MRI were significantly correlated (R(2)  = 0.85; P < 0.01), there was approximately 33% systematic underestimation by the latter technique. DCE MRI showed a significant decrease in maternal placental perfusion in reperfusion-reoxygenation phase in the saline, 0.44 ± 0.06 mL/min/g (P = 0.012, t-test), but not in the antioxidant group, 0.62 ± 0.06 mL/min/g, relative to pre-occlusion values (0.77 ± 0.07 and 0.84 ± 0.12 mL/min/g, correspondingly).
  
  
  CONCLUSIONS
  Underestimation of true perfusion in placenta by steepest slope DCE MRI is significant and the error appears to be systematic.
authors: Department of Pediatrics NorthShore.
authors: Alexander
authors: A
authors: Drobyshevsky
authors: Radiology, NorthShore University HealthSystem, Evanston, IL.
authors: P V
authors: PV
authors: Prasad
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000737:chemistry; D002138:Calibration; D003287:Contrast Media / Q000737:chemistry*; D005260:Female; D005456:Fluorescent Dyes / Q000737:chemistry; D019786:Gadolinium DTPA / Q000737:chemistry; D000860:Hypoxia / Q000473:pathology; D007091:Image Processing, Computer-Assisted; D007511:Ischemia / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008863:Microspheres; D010477:Perfusion; D019047:Phantoms, Imaging; D010920:Placenta / Q000473:pathology*; D011247:Pregnancy; D011817:Rabbits; D014599:Uterus / Q000473:pathology*
chemical_list: D000975:Antioxidants; D003287:Contrast Media; D005456:Fluorescent Dyes; D019786:Gadolinium DTPA
keywords: antioxidants; dynamic contrast imaging; perfusion; placenta; reperfusion