Foraminal disc with nerve root impingement

Case contributed by Dr Ian Bickle


Back pain with radiation into the left leg. Non responsive to conservative management.

Small (<1 cm) left far foraminal disc at L3/L4, which is impinging on the exiting L3 nerve just after it enters the exit foramen (best observed on the T1 sequences).

The central canal is capacious at this level. The remaining levels are normal.

Annotated image

The blue circle outlines a normal exit foramen with a key-hole like shape with the nerve root enveloped in fat.

The red arrow indicates the absence of fat in the posteroinferior aspect of the exit foramen with a far lateral disc abutting the exiting nerve root.

Annotated image

The types of disc nomenclature.

Illustration courtesy of Frank Gaillard.

Case Discussion

Foraminal lateral discs are one of the less commonly identified disc protrusions when imaging the lumbar spine. The findings may be relatively subtle, but symptoms can be pronounced.

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Case information

rID: 44881
Published: 17th May 2016
Last edited: 28th Oct 2019
Inclusion in quiz mode: Included