Abstract 3804: Regression of DWI Lesion is Frequent and is Associated with Outcome after Endovascular Therapy for Acute Ischemic Stroke
Background: Hyperintensity on diffusion weighted imaging (DWI) on MRI obtained ultra-early is hypothesized to represent core ischemic lesion in patients with acute ischemic stroke. However, resolution of a part of DWI lesion is well known. We evaluated the evolution of the hyperintensity on DWI among acute stroke patients who underwent endovascular recanalization therapy.
Methods: We reviewed prospective database of early MRI imaging in screening for endovascular therapy in acute stroke from May 2010 to July 2011. We included patients who had both pre-treatment and follow-up MRI. We assessed the change in DWI lesion volumes among these patients. Patients were divided into 2 groups: “growth group” (patients showing more than 10 % increase in lesion volumes), “non-growth group” (patients showing less than 10 % increase or decrease in lesion volumes). Stroke severity was assessed by the National Institutes of Health Stroke Scale (NIHSS) score at arrival and discharge. We compared patient’s backgrounds, imaging findings, endovascular therapy, and Thrombolysis in Myocardial Infarct (TIMI) flow grade following endovascular therapy between “growth” and “non-growth” group.
Results: Fifty four patients underwent acute endovascular therapy. Of these, 30 patients (56 %) had both pre-treatment and follow-up MRI. The median time between stroke onset to initial MRI was 257 minutes, and follow-up MRI were performed at median 2.5 days after endovascular therapy. Decrease of DWI lesion volume was seen in 5 patients (17 %) with median volume decrease of 15 ml among the 5 patients. Total of seven patients had decrease or <10% growth of DWI lesion. There were no differences in pre-treatment NIHSS score or DWI lesion volume between the “non-growth” and “growth” groups. The “non-growth” group had a lower NIHSS score at discharge (median, 3 versus 14, p = 0.013) compared to that of growth group. TIMI recanalization grade 2 or 3 (88 % versus 87%, p = 1.000), or TIMI recanalization grade 3 (14 % versus 26 %, p = 1.000) were not different between the two groups.
Conclusion: Patients without growth of DWI lesion may have good outcome. Decrease of DWI hyperintense lesion was observed in about one-fifth of patients who underwent endovascular therapy. However, that was not associated with the degree of recanalization.
- © 2012 by American Heart Association, Inc.