Imaging Evaluation of SAH and Aneurysm
Last Updated: October 1, 2018
- Subarachnoid Hemorrhage (SAH)
- Ruptured intracranial aneurysm (80% of non-traumatic cases).
- Vascular malformations (up to 5% of cases).
- Imaging workup
- Non-enhanced CT (NECT) of the head (sensitivity 98%)
- Performed if NECT positive
- Specificity 100%, sensitivity 96-99.7% for >4mm aneurysms
- Uncommonly used for acute SAH
- For more information, please see the corresponding chapter in Radiopaedia
- Incidence of intracranial aneurysms is 2-3% in the general population
- Saccular aneurysms
- Typically arise at arterial branch points
- Far more common than intracranial arterial dissections and dissecting pseudoaneurysms
- May be associated with high velocity flow phenomena
- Feeding vessels to dural AVFs ...