title: Magnetic resonance angiography of thromboembolic stroke in rats: indicator of recanalization probability and tissue survival after recombinant tissue plasminogen activator treatment.
abstract: Magnetic resonance angiography (MRA) was performed in a thromboembolic stroke model of the rat to characterize intracranial vessel occlusion patterns and to test its predictive power for tissue recovery after recombinant tissue plasminogen activator (rt-PA) treatment. After rt-PA-treated selective middle cerebral artery (MCA) occlusion, full recanalization was observed in two of three animals, whereas additional occlusion of the circle of Willis (CW) resulted in full vascular flow restitution in only one of six rats. Tissue reperfusion markedly lagged the onset of treatment, and the delay correlated with the pattern of vessel occlusion (20 to 23 minutes for selective MCA occlusion vs. 71 to 79 minutes for combined MCA/CW occlusion). In lateral cortex and striatum the apparent diffusion coefficient decreased to 78 +/- 15% of control after embolization, recovered to 80% to 85% after rt-PA treatment of selective MCA occlusion, but further declined to 66% to 69% after combined MCA/CW occlusion. Correspondingly, T2 relaxation time increased to 107% to 118% of control after selective MCA occlusion and to 112% to 124% after combined MCA/CW occlusion in these regions. The present investigation shows that MRA provides valuable information on the severity of thromboembolic stroke and has the power to predict, before the initiation of treatment, the functional tissue outcome after rt-PA-induced thrombolysis.
authors.affiliation: Department of Experimental Neurology, Max-Planck-Institute for Neurological Research, Köln, Germany. hilger@mpin-koeln.mpg.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Hilger
authors.forename: Frank
authors.initials: F
authors.lastname: Niessen
authors.forename: Michael
authors.initials: M
authors.lastname: Diedenhofen
authors.forename: Konstantin-Alexander
authors.initials: KA
authors.lastname: Hossmann
authors.forename: Mathias
authors.initials: M
authors.lastname: Hoehn
mesh_terms: D000818:Animals; D001929:Brain Edema / Q000175:diagnosis / Q000188:drug therapy / Q000473:pathology; D002548:Cerebral Revascularization; D002560:Cerebrovascular Circulation / Q000187:drug effects; D005343:Fibrinolytic Agents / Q000494:pharmacology*; D020244:Infarction, Middle Cerebral Artery / Q000175:diagnosis* / Q000188:drug therapy* / Q000473:pathology; D020767:Intracranial Thrombosis / Q000175:diagnosis* / Q000188:drug therapy* / Q000473:pathology; D018810:Magnetic Resonance Angiography; D008297:Male; D011237:Predictive Value of Tests; D051381:Rats; D017208:Rats, Wistar; D013923:Thromboembolism / Q000175:diagnosis / Q000188:drug therapy / Q000473:pathology; D010959:Tissue Plasminogen Activator / Q000494:pharmacology*
chemical_list: D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator