Abstract W MP19: MRI Voxel-Based Profiling of Tissue Viability and Ischemia in Acute Ischemic Stroke: Elimination of Time as a Treatment Barrier?
BACKGROUND: Despite its proven efficacy in acute ischemic stroke, thrombolytic treatment rates are exceedingly low. A common barrier is a prerequisite estimation of finite event duration. Whole-brain MR DWI-FLAIR comparative methods of hyperacute-acute ischemic match/mismatch are currently under investigation as a potential surrogate for unknown duration. Profiles that reflect field ischemia but not viability may not detect important voxel-level heterogeneity and, consequently, areas that may potentially benefit from revascularization. Voxel-based MR methods that assess viability (PWI) and ischemia (DWI-FLAIR) may afford a more informative measure to determine and expand treatment eligibility.
METHODS: Consecutive, treated M1 ischemic stroke patients with serial MRI were analyzed with voxel-based, volumetric measures of DWI, FLAIR, and PWI for match/mismatch. Co-registration of Day 0 DWI, PWI, and FLAIR with Day 5/discharge FLAIR was then followed by ROI analysis of the affected MCA field. Day 0 DWI, PWI, FLAIR and Day 5/discharge FLAIR voxels were pooled into average populations according to positivity. Serial voxel-populations were then quantified at Day 0 and at Day 5/discharge individually and group-wise. Data processing and analysis were performed with MatLab, 3DSlicer, and Microsoft Excel.
RESULTS: 38 treated M1 occlusive patients (mean age 65 years, 25 female) underwent a voxel-based analysis of DWI, PWI, and FLAIR at day 0 and FLAIR at day5/discharge. At baseline, 93% of the affected MCA field was DWI-/PWI+/FLAIR-; 7% was DWI+/PWI+/FLAIR-; and ~3% was FLAIR+. At day 5/discharge, 36% of baseline at-risk field (DWI-/PWI+); >95% of baseline field undergoing ischemia (DWI+/PWI+); and 94% of baseline ischemic tissue (FLAIR+) were FLAIR+.
CONCLUSIONS: Voxel-based analyses of DWI, PWI and FLAIR on serial MRI reveal heterogeneity of voxel status at baseline and in tissue fate, and provide a dynamic tissue profile in treated M1 ischemic stroke. Over 1/3 of baseline viable tissue became ischemic at day 5 suggesting nearly 2/3 of the field remained viable. Future evaluations of voxel-based approaches that profile viability and ischemia are warranted to validate this methodology and its potential to expand acute stroke treatment eligibility.
Author Disclosures: A.P. Tansy: None. F. Scalzo: None. S. Starkman: None. L.K. Ali: None. D. Kim: None. P.M. Vespa: None. N.M. Rao: None. A. Yallapragada: None. J.R. Alger: None. N. Salamon: None. J.L. Saver: Consultant/Advisory Board; Significant; COVIDIEN. D.S. Liebeskind: Research Grant; Significant; NIH/NINDS K24NS072272, NIH/NINDS P50NS044378. Consultant/Advisory Board; Modest; COAXIA. Consultant/Advisory Board; Significant; STRYKER/CONCENTRIC.
- © 2014 by American Heart Association, Inc.