The goal of this clinical trial is to investigate the use of DECT (Dual-Energy Computed Tomography) in patients with acute ischemic stroke who receive an intervention (thrombolysis or thrombectomy). The main questions to answer are: 1. Can DECT more accurately differentiate hyperdensities as intracranial haemorrhage (ICH) or contrast extravasation compared with single-energy CT (SECT)?. 2. Will DECT lead to better care for patients with AIS who receive intervention and have post-procedural hyperdensities? Patients who receive intervention for acute ischemic stroke (AIS) receive a SECT at 24 hours as standard of care to determine if ICH is present. In the current study, a DECT will be done in addition to the SECT. Followup imaging (SECT or MRI) will be done at 72 hours to determine if the hyperdensity was indeed ICH. The accuracy of DECT for differentiating ICH from contrast extravasation will be compared.