Endovascular thrombectomy (EVT) has been a standard of care in patients with acute ischemic stroke (AIS) patients due to large vessel occlusion (LVO) within 8-hour therapeutic time window. Although stroke imaging plays an important role in triage of stroke patients, there were great variabilities in the use of imaging tools for patient selection in the recent randomized control trials.
　　In addition to non-contrast computed tomography (CT) and computed tomographic angiography (CTA), other advanced imaging tools including multiphase CTA, CT perfusion (CTP), diffusion/perfusion magnetic resonance imaging (MRI), and magnetic resonance angiography (MRA), were used. Those imaging modalities help identify patients with extent of collateral circulation in ESCAPE trial, perfusion mismatch in EXTEND-IA, SWIFT PRIME, and DEFUSE 3 trials, or clinical-imaging mismatch in the DAWN trial.
　　Non-contrast CT is widely available and can be performed within a few minutes of arrival. Contrast-enhanced CTA of head and neck is used with high sensitivity and specificity for evaluation of cerebral vasculature and LVO. MRI/MRA can also be used to evaluate AIS and LVO. Diffusion weighted image (DWI) is highly sensitive and specific for the detection of early ischemic changes within the first 6 hours of symptom onset. Timely reperfusion therapy may reverse diffusion abnormalities; on the other hand, diffusion abnormalities are often irreversible without successful reperfusion.
　　In this presentation, a variety of imaging manifestations in stroke would be presented with different clinical conditions, which may affect the decision-making of the following endovascular thrombectomy.