- downward displacement of the midbrain
- diffuse, smooth dural enhancement
- distended dural sinuses
- subdural hematoma or hygroma
Absence of one of these signs does not preclude the diagnosis.
The dural enhancement in intracranial hypotension is pachymeningeal (dura-arachnoid) and is seen along the inner table of the skull, as opposed to leptomeningeal enhancement (arachnoid-pia) which is seen on the surface of the brain.
The differential for dural enhancement includes:
- meningitis - leptomeningeal enhancement
- dural metastases - scattered, "bumpy" enhancement
- granulomatous disease (sarcoid, TB) - nodular enhancement
- meningioma with focal enhancement of the dural tail
- postoperative changes - transient
Smirniotopoulous JG, Murphy FM, Rushing EJ, et al. Patterns of contrast enhancement in the brain and meninges. Radiographics 2007;27:525-51.