Figure 1

Advanced degenerative changes of the L4/5 facets are seen on these AP radiograph and CT scan images. (1A, B and D) Note the subchondral sclerosis and cystic changes. The axial T2 MRI image shows a focal fluid-like collection in bilateral L4/5 facet joints with contiguous extension into the midline dorsal epidural space (dotted line) (1C). Additionally, there is heterogeneous increased signal in the paravertebral muscles. There is no evidence of spondylodiscitis or paravertebral muscle abcess.