Background Reperfusion therapies, i.e., intravenous thrombolysis (IVT) and/or endovascular thrombectomy (EVT), are most effective treatments in the management of acute ischemic stroke (AIS) patients. The benefits of reperfusion therapies, however, may be reduced by treatment delays due to tests and examinations and logistic issues. Emergency Stroke Unit (ESU), a new concept of stroke unit locating at the Accident and Emergency Department (AED), equipped with a mobile, low-field MR imaging (lfMRI) scanner for fast diagnosis of ischemic stroke, differentiation of intracranial hemorrhage and identification of large vessel occlusion (LVO), is being tested in Mainland China. It may shorten the door-to-needle time (DNT) for IVT and door-to-groin puncture time (DPT) for EVT, which may hance associate with improved functional outcomes of AIS patients. This is a prospective, single-center, open-label, non-randomized, single-arm study aims to evaluate the safety and efficacy of the ESU workflow using lfMRI in shortening the DNT/DPT and improving functional outcomes in AIS patients, who are potentially eligible for IVT and/or EVT and can be treated within 6 hours after onset, compared with standard practice in Hong Kong; to reveal the changes in the ischemic lesions over a few days after IVT/EVT in these patients, with serial follow-up lfMRI exams.