title: Correlation between CT and diffusion-weighted imaging of acute cerebral ischemia in a rat model.
abstract: OBJECTIVE
  The quantitative temporal relationship between changes in CT attenuation, ADC value, and DWI signal intensity of acute ischemic tissue has not yet been determined in an animal model. This study was performed to determine the temporal relationship between CT attenuation, ADC value, and DWI signal intensity in acute cerebral ischemia.
  
  
  METHODS
  CT and DWI were performed at 1, 3, 5, 7, and 9 hours after left MCA occlusion in 11 rats. Mean values for CT attenuation, ADC, and DWI signal intensity were determined for the ischemic hemisphere and contralateral normal hemisphere. Temporal changes in each mean value and the relationship between CT attenuation and ADC value and DWI signal intensity were evaluated.
  
  
  RESULTS
  The decrease of CT attenuation and the increase of DWI signal intensity occurred gradually after MCA occlusion, while ADC value decreased rapidly at 1 hour. Although correlation was significant between time and rCT or rDWI (P<.01, respectively), no correlation between time and rADC was found (P=.33). There was a significant linear correlation between rCT and rDWI (r=0.497, P<.01), but no significant correlation between rCT and rADC (P=.509) was found.
  
  
  CONCLUSIONS
  The temporal change in CT attenuation was different from that in ADC value with no significant linear correlation between CT attenuation and ADC value for acute cerebral ischemia. However, rCT and rDWI showed a modest correlation.
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: H S
authors.initials: HS
authors.lastname: Seo
authors.forename: D G
authors.initials: DG
authors.lastname: Na
authors.forename: J-h
authors.initials: JH
authors.lastname: Kim
authors.forename: K W
authors.initials: KW
authors.lastname: Kim
authors.forename: K-R
authors.initials: KR
authors.lastname: Son
mesh_terms: D000208:Acute Disease; D000818:Animals; D002545:Brain Ischemia / Q000000981:diagnostic imaging* / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging; D004195:Disease Models, Animal; D020244:Infarction, Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008954:Models, Biological; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D014057:Tomography, X-Ray Computed