63-year-old with acute low back pain extending down left leg with pain and numbness

T2 axial at L5/S1                                                                        T2 sagittal at left side

T1 axial pre and post Gad at L5/S1 leve         T1 sagittal pre and post Gad at left side

Findings:

There is a large left foraminal and far lateral soft tissue mass which compresses the exiting L5 nerve root on this side. It enhances peripherally but not centrally.

DDX:

Disc extrusion or fragment, nerve sheath tumor (neurofibroma or schwannoma)

Diagnosis:

Left L5/S1 foraminal disc extrusion.

Discussion:

The location, relatively dark T2 signal and lack of central enhancement as well as the acute presentation make the diagnosis of disc extrusion.

Submitted by Ahmed Hassanin Negila, MD and Jerry Jarvik, MD, UW Neuroradiology