title: Prediction of Reperfusion-Associated Hemorrhagic Transformation Using Dynamic Contrast-Enhanced Imaging in a Rat Stroke Model.
abstract: OBJECTIVE
  Reperfusion-associated hemorrhagic transformation (HT) is an important complication of recanalization therapy. A method to identify stroke victims that may undergo HT will improve the patient selection and safety of this treatment. In this study, we determined the relationship between timing of reperfusion and the frequency and severity of HT, and whether very early dynamic contrast-enhanced (DCE) imaging predicts the occurrence of reperfusion-associated HT in a model of experimental stroke.
  
  
  METHODS
  Intraluminal suture occlusion of the middle cerebral artery was used to produce transient ischemia in male Sprague Dawley rats (n = 50). Reperfusion was performed by withdrawal of the occluding filament after 3 (n = 10), 4 (n = 10), 5 (n = 10), 6 (n = 10), or 7 (n = 10) hours. Magnetic resonance imaging studies were performed before reperfusion using DCE, susceptibility-weighted imaging, diffusion-weighted imaging, and T2- and T1-weighted imaging. Follow-up magnetic resonance imaging and histological studies were performed at 24 hours.
  
  
  RESULTS
  Hemorrhagic transformation occurred by 24 hours after injury in 8 of 50 animals. The HT rate increased with prolonged ischemic duration. All animals exhibiting acute blood-brain barrier (BBB) perturbation subsequently developed HT by 24 hours. Statistically significant differences in the BBB permeability parameters (P < 0.05) between the HT group and non-HT group were detected by DCE imaging. There were also statistically significant differences (P < 0.05) between the HT area and adjacent HT area. Among the permeability parameters, subcortex rK was the most sensitive and specific predictor of HT.
  
  
  CONCLUSIONS
  The results suggest that the use of quantitative BBB measurements may further improve early prediction and identification of HT. The DCE parameters were the sensitive early independent predictor of reperfusion-associated HT.
authors.affiliation: From the Departments of *Radiology and †Radiotherapy, Hainan General Hospital, Haikou, Hainan Province; ‡Department of Radiology, Huashan Hospital, Fudan University; and §Department of Radiology, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China.
authors.forename: Wei-Yuan
authors.initials: WY
authors.lastname: Huang
authors.forename: Gang
authors.initials: G
authors.lastname: Wu
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: Li
authors.forename: Dao-Ying
authors.initials: DY
authors.lastname: Geng
authors.forename: Wen-Li
authors.initials: WL
authors.lastname: Tan
authors.forename: Xiang-Rong
authors.initials: XR
authors.lastname: Yu
mesh_terms: D000818:Animals; D002543:Cerebral Hemorrhage / Q000150:complications / Q000473:pathology*; D003287:Contrast Media; D004195:Disease Models, Animal; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000473:pathology*; D020521:Stroke / Q000150:complications / Q000473:pathology*
chemical_list: D003287:Contrast Media