Synovial Cyst MRI

Imaging diagnosis: Facetal joint Synovial Cyst of Lumbar Spine

• Findings: Cystic lesion with low T1, high T2 extradural lesion contiguous and in relation with the facet joint, surrounding enhancement on post contrast T1. Mass effect, causing compression over corresponding traversing nerve root in lateral recess.
• Associated with degenerated joints – 75% at L4-5
• Typically posterolateral.
• Contents variable – clear fluid, calcium, hemorrhage.

• DDs
– Migrated herniated disc.
– Peri neural sleeve cyst (close to nerve root)
– Schwannoma (iso intense solid signal, low signal capsule)
– Hematoma.