The conus and lower thoracic cord are normal.
L4/5 large extruded disc occupying almost all of the cross sectional area of the canal at this level. Severe cauda equina compression.
No foraminal extension. L5/S1 and L3/4 disks dessicated, but no significant canal stenosis or nerve root compression.
Conclusion:
Very large L4/5 disc extrusion with marked cauda equina compression.