MR recognition of posterior lumbar vertebral ring fracture.

Four cases of lumbar vertebral ring fracture, in which magnetic resonance (MR) was used, were reviewed. The MR features included (a) discontinuity and truncation of the posteroinferior vertebral body, (b) displacement of the avulsed low signal fragment, and (c) disk prolapse subjacent to the fragment. Recognition of these findings may eliminate the need for other diagnostic studies.