What is a disc herniation?
A disc herniation is considered as a localized or focal displacement of disc material beyond the limits of the intervertebral disc space.
What is the difference between a disc protrusion and a disc extrusion?
The difference is based on the shape of the displaced disc material. If the dimension of the base of the herniated disc is wider than the dome in both axial and sagittal planes it is a protrusion, if the base is narrower than the dome in at least one plane it is referred to as extrusion.
Axial images were acquired at the L1/2 to L3/4 disc levels.
Uncontained disc herniation at the L2/3 disc level, extending horizontally from the left subarticular zone into the left foraminal zone consistent with a disc extrusion with migration/sequestration of disc material into the left foramen.
Posterior displacement of the left L2 nerve root.
Mild effacement of the left anterolateral thecal sac.
Additional findings:
Mild contained disc herniation at the L3/4 disc level in the right subarticular/foraminal zone consistent with a disc protrusion.
Thickening of the ligamentum flavum at disc level L1/2 to L4/5 level.