TY - JOUR T1 - Location of the Clot and Outcome of Perfusion Defects in Acute Anterior Circulation Stroke Treated with Intravenous Thrombolysis JF - American Journal of Neuroradiology JO - Am. J. Neuroradiol. DO - 10.3174/ajnr.A3149 AU - N. Sillanpää AU - J.T. Saarinen AU - H. Rusanen AU - I. Elovaara AU - P. Dastidar AU - S. Soimakallio Y1 - 2012/06/21 UR - http://www.ajnr.org/content/early/2012/06/21/ajnr.A3149.abstract N2 - BACKGROUND AND PURPOSE: The location of the clot is a major determinant of ischemic stroke outcome. We studied the impact of the location (ICA, proximal M1 segment of the MCA, distal M1 segment, and M2 segment and more distally) of the clot on the CT perfusion parametric maps, the mismatch ratio, the amount of salvaged brain tissue, and the imaging and clinical outcomes in a retrospective acute (<3 hours) stroke cohort treated with intravenous thrombolysis. MATERIALS AND METHODS: We reviewed 105 patients who underwent admission multimodal CT that revealed an occluded vessel on CTA. CT perfusion was successfully performed in 58 patients (55%). Differences among the parameters in different vessel positions were studied with the ANCOVA by using onset-to-imaging time as a covariate followed by pair-wise testing. RESULTS: There were no significant differences in potential confounding variables among the groups. A clot proximal to the M2 segment produced a significantly larger defect on the MTT map. A clot in the ICA resulted in a significantly larger CBV lesion compared with the distal M1 segment, the M2 segment, and the M3 segment. In general, a more proximal thrombus created a larger CBV defect. The fraction of penumbra that was salvaged at 24 hours was higher in the more distal vessel positions. CONCLUSIONS: Admission CBV defects are larger in proximal vessel occlusions. More of the penumbra can be salvaged if the occlusion is located more distally. This effect seems to reach a plateau in the distal M1 segment of the MCA. Abbreviations ANCOVAanalysis of covarianceASPECTSAlberta Stroke Program Early CT ScoreCBSclot-burden scoreICCintraclass correlation coefficientmRSmodified Rankin Scale ER -