 Introduction/Background Cerebrovascular diseases encompass a range of varied clinical presentations and disease processes. This document focuses on clinical scenarios related to stroke and intraparenchymal hemorrhage (IPH), stroke-like conditions such as venous sinus thrombosis and arterial vascular dissection, and known vascular stroke-related risk factors such as cervical bruit and carotid stenosis. The clinical variants included in this document describe imaging management early in clinical presentation with acute or recent onset of symptoms, as well as ongoing imaging during management of known stroke and stroke-related conditions in the subacute and chronic phases. The subset of cerebrovascular diseases and presentations are broad and varied; therefore, the introduction and background of each variant will be discussed individually. Special Imaging Considerations In many stroke-related clinical scenarios, both parenchymal and vascular imaging procedures are commonly used, particularly in the initial imaging of acute clinical presentations. Noncontrast head CT can be performed rapidly, either alone or included in the performance of CT angiography (CTA) of the head. For the purposes of this document, both procedures are discussed separately for each variant, highlighting the individual usefulness of both the noncontrast examination and contrast-enhanced vascular imaging phase. CTA of the head and neck are often acquired together, using a single contrast bolus for optimal arterial vascular opacification. Although the diagnostic usefulness and/or acuity of intracranial and extracranial vascular assessment may differ within a particular clinical context, the benefit of combined neck and head vascular imaging may have added clinical benefit in circumstances in which transcatheter arterial intervention is a potential consideration.
Cerebrovascular Diseases Stroke and Stroke Related Conditions PCAs.  Introduction/Background Cerebrovascular diseases encompass a range of varied clinical presentations and disease processes. This document focuses on clinical scenarios related to stroke and intraparenchymal hemorrhage (IPH), stroke-like conditions such as venous sinus thrombosis and arterial vascular dissection, and known vascular stroke-related risk factors such as cervical bruit and carotid stenosis. The clinical variants included in this document describe imaging management early in clinical presentation with acute or recent onset of symptoms, as well as ongoing imaging during management of known stroke and stroke-related conditions in the subacute and chronic phases. The subset of cerebrovascular diseases and presentations are broad and varied; therefore, the introduction and background of each variant will be discussed individually. Special Imaging Considerations In many stroke-related clinical scenarios, both parenchymal and vascular imaging procedures are commonly used, particularly in the initial imaging of acute clinical presentations. Noncontrast head CT can be performed rapidly, either alone or included in the performance of CT angiography (CTA) of the head. For the purposes of this document, both procedures are discussed separately for each variant, highlighting the individual usefulness of both the noncontrast examination and contrast-enhanced vascular imaging phase. CTA of the head and neck are often acquired together, using a single contrast bolus for optimal arterial vascular opacification. Although the diagnostic usefulness and/or acuity of intracranial and extracranial vascular assessment may differ within a particular clinical context, the benefit of combined neck and head vascular imaging may have added clinical benefit in circumstances in which transcatheter arterial intervention is a potential consideration.