This research takes patients with cerebrovascular diseases as the research subjects and employs the experimental design of a prospective cohort study, aiming to innovatively develop and validate a "one-stop" multimodal CT examination scheme. The 301-CTAP multimodal CT technique implies that three modalities are acquired through a single collection, including head and neck CTA (head and neck CTA), multiphase CTA imaging of the brain (multiphase CTA), and CT perfusion imaging of the brain (CT perfusion).