Volumetric evaluation of the ischemic lesion size with serial MRI in a transient MCAO model of the rat: comparison of DWI and T1WI.
Magnetic resonance imaging (MRI) is applied in many studies on experimental cerebral ischemia in rodents to monitor the temporal evolution of ischemic damage. We report a protocol to evaluate the infarct size after middle cerebral artery occlusion with reperfusion (MCAO/R) in male Wistar rats. Imaging was performed with a 2.35 T scanner and we focused on diffusion-weighted imaging (DWI), T2-weighted imaging (T2WI) and postcontrast T1-weighted imaging (T1WI). We show the detailed procedure of volumetry, the contrast-to-noise ratio (CNR) and the intraindividual variability of infarct and hemispheric volumes at different reperfusion times. The presented method is of low variability if image contrast between ischemic and nonischemic tissue is very high, which is the case not only for all sequences at 8 and 12 h of reperfusion but also for DWI after 3 and 5 h of reperfusion. Furthermore, we describe the so-called mismatch region of lesion sizes depicted on DWI and postcontrast T1WI that suffers from cytotoxic edema but lacks contrast enhancement.
Nagel
Simon
S
Department of Neurology, University of Heidelberg, Medical School, INF 400, 69112 Heidelberg, Germany. simon_nagel@med.uni-heidelberg.de
Wagner
Simone
S
Koziol
James
J
Kluge
Britta
B
Heiland
Sabine
S
D000818:Animals; D001921:Brain / Q000473:pathology* / Q000503:physiopathology; D001929:Brain Edema / Q000175:diagnosis / Q000503:physiopathology; D002544:Cerebral Infarction / Q000175:diagnosis* / Q000503:physiopathology; D003287:Contrast Media / Q000008:administration & dosage; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D004195:Disease Models, Animal; D018450:Disease Progression; D019786:Gadolinium DTPA; D007089:Image Enhancement / Q000379:methods; D020244:Infarction, Middle Cerebral Artery / Q000175:diagnosis* / Q000503:physiopathology; D002546:Ischemic Attack, Transient / Q000175:diagnosis* / Q000503:physiopathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D011237:Predictive Value of Tests; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000175:diagnosis / Q000503:physiopathology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D003287:Contrast Media; D019786:Gadolinium DTPA