Intracranial Structures That Exhibit Contrast Enhancement. CT Head with contrast is usually performed to identify mass lesions or vascular abnormalities.
- Normal: Major cerebral arteries (Circle of Willis), venous sinuses, and pial vessels on surface of cerebral cortex
- Abnormal: AVM, large aneurysms
Structures outside the blood–brain barrier
- Dura: Falx, tentorium
- Extra-axial tumors: Meningioma, cranial nerve tumor (homogeneous enhancement)
Intracerebral lesions whose vascular supply does not have an intact blood–brain barrier
Enhancement typically often has a ring-like pattern—the surface of the lesion being is well vascularized and the central region poorly vascularized, necrotic or cystic.