Noninvasive imaging techniques are playing an ever-increasing role in the diagnosis and management of patients with lesions of the vascular structures of the head and neck. Stroke is the most important clinical indications for which patients undergo emergent imaging. Computed tomography angiography (CTA) is accurate, more rapid, less expensive, and requires less staffing than surgical exploration or conventional angiography. Initial noncontrast CT followed immediately by CTA and CTP provides a rapid yet thorough assessment of potential intracranial hemorrhage, stroke mimics, large evolved infarct, arterial clot and stenosis, infarct size and location, and penumbra. Many patients who present with signs of trauma to the head, neck, or great vessels receive noncontrast CT imaging as part of the initial diagnostic workup. Technical factors such as slice thickness, length of coverage, kilovolt and milliampere settings, and bolus delay time can influence the accuracy and speed with which a CTA is obtained.