Spinal Epidural Fluid Collection

Differential considerations for an epidural fluid collection in the spine:

• Arachnoid cyst (shown above): Nonenhancing loculated collection that follows cerebrospinal fluid signal. Can be intradural or extradural.
• Facet synovial cyst: Associated with facet arthropathy and located along the posterolateral aspect of spinal canal adjacent to the facet joint.
• Pseudomeningocele: Look for evidence of prior trauma (e.g., surgery).
• Abscess:
• Epidural hematoma: Look for blooming on T2* images.
• Idiopathic spinal cord herniation: Herniation of the cord through a ventral dural defect. Ventral deviation of the cord can mimic a posterior epidural collection. May be associated with an arachnoid cyst due to adhesions.