Decreased infarct volume and intracranial hemorrhage associated with intra-arterial nonionic iso-osmolar contrast material in an MCA occlusion/reperfusion model

Abstract

BACKGROUND AND PURPOSE: Infarct volume and intracranial hemorrhage after reperfusion with nonionic low-osmolar and isoosmolar iodinated IRCM has not been previously compared. We postulated that iso-osmolar and low-osmolar iodinated contrast media exert varied effects on cerebral infarct after intra-arterial injection. We compared infarct volume and hemorrhagic changes following intra-arterial infusion of iodixanol, iopamidol, or normal saline in a rat MCA occlusion/reperfusion model. MATERIALS AND METHODS: Infarct was induced in 30 rats by a previously validated method of MCA suture occlusion. Reperfusion was performed after 5 hours with either iodixanol (n=9), iopamidol (n=12), or saline (n=9). MR images were obtained at both 6 and 24 hours after ischemia, followed by sacrifice. Infarct volume was measured with T2WI and DWI by semiautomatic segmentation. Incidence and area of hemorrhage were measured on brain sections postmortem. RESULTS: T2WI mean infarct volumes were 242 ± 89, 324 ± 70, and 345 ± 92 mm3 at 6 hours, and 341 ± 147,470 ± 91, and 462 ± 71 mm3 at 24 hours in the iodixanol, iopamidol, and saline groups, respectively. Differences in infarct volume among groups were significant at 6 hours (P < .01). CONCLUSIONS: Intra-arterial infusion of nonionic iso-osmolar iodixanol showed reduced infarct volume and reduced cortical intracranial hemorrhage areas in comparison with nonionic low-osmolar iopamidol and saline. Our results may be relevant in the setting of intra-arterial therapy for acute stroke in humans, warranting further investigation.