DWI-ADC Mismatch Predicts Infarct Growth and Endovascular Thrombectomy Outcomes in Anterior Circulation Stroke

BackgroundCurrent automatic software uses a fixed apparent diffusion coefficient (ADC) threshold ([&le;]620x10- mm{superscript 2}/s) to quantify stroke volume for endovascular thrombectomy (EVT) decision-making. In contrast, clinical evaluation relies on visual identification of DWI hyperintensity with corresponding ADC hypointensity--which may exhibit varied ADC values in hyperacute stroke. This study investigates the clinical and imaging significance of the significant discrepancy between DWI hyperintense volume and ADC [&le;] 620 x 10- mm{superscript 2}/s volume on pre-EVT magnetic resonance imaging (MRI), defined as DWI-ADC mismatch. MethodThis retrospective, single-center study analyzed consecutive patients diagnosed with acute ischemic stroke (AIS) between January 2018 and January 2020. Inclusion criteria consisted of patients with symptomatic anterior circulation large vessel occlusion (LVO) within 24 hours and treated by EVT, with high-quality pre- and post-EVT MRI scans. Infarct segmentation was performed by neuroradiologists. DWI-ADC mismatch was defined as a ratio of segmented DWI volume to ADC volume ([&le;]620x10- mm{superscript 2}/s) [&ge;]2. Data on demographics, baseline and follow-up clinical and imaging characteristics, procedural details, and outcomes were collected and analyzed. Result73 patients were included in the study, with 20 patients (27.4%) demonstrating a DWI-ADC mismatch. The mismatch group exhibited a significantly slower infarct growth rate (3.8 vs. 7.5 ml/h, P = 0.04), higher prevalence of parent artery stenosis (65% vs. 20.8%, P < 0.001) and a greater need for angioplasty and/or stenting (50% vs. 17%, P < 0.001). Imaging analysis showed a higher percentage of DWI reversal (37.7% vs. 21.2%, P = 0.02) and a trend toward lower ADC lowering percentage (25.3% vs. 32.2%, P = 0.05) in the mismatch group. Demographics, baseline and follow-up lesion volumes, and functional outcomes were comparable between groups. ConclusionDWI-ADC mismatch identifies a distinct subgroup of stroke patients with slower infarct progression and unique procedural needs. Incorporating mismatch evaluation into pre-EVT imaging may refine patient selection and optimize treatment strategies.