Delineation abnormality in the intervertebral disc as seen in X-rays. It is subject to various interpretations, and sometimes causes communication difficulties. In simple terms, it refers to a diffuse protrusion of disc material beyond the back margins of the vertebral endplates without significant irregularity or degree of focus. The outer fibers of the annulus fibrosus are intact.

a diffuse outpocketing of the disc from the vertebral column, usually associated with some disc space collapse

an example of a contained disc disorder

a non-specific term, which is often used erroneously