History of L3-L4, L4-L5 fusion. L1-L2 cyst. Evaluate for change in cyst size or abnormality. Right-sided low back pain. Five lumbar type vertebral bodies are present. Vertebral body heights are within normal limits. Alignment is grossly within normal limits, aside from perhaps minimal L4 on L5 anterolisthesis. Bone marrow signal is benign. The conus medullaris is normal in position. Postoperative changes of prior surgical fusion from L3 to L5 are again seen. Bilateral paraspinous rods, pedicle screws, and interbody grafts were better assessed on recent CT, which showed bony bridging.Susceptibility artifact from hardware slightly limits exam. Mild multilevel degenerative changes are seen including disc desiccation. Individual levels as below: L1-L2: There is approximately 5 x 6 x 7 mm lesion with T2 hyperintensity and peripheral enhancement involving the dorsal epidural soft tissues to the right of the midline abutting the ligamentum flavum. The lesion projects anteriorly with mild mild effacement of the dorsal thecal sac. Mild facet arthropathy with surrounding enhancement. There is also mild edema involving the right pedicle/transverse process junction.Disc desiccation and mild disc bulge also seen. Overall no significant central canal stenosis. Neural foramina are patent.L2-L3: No significant disc disease. No spinal canal or neural foraminal stenosis. Mild facet arthropathy.L3-L4: No significant disc disease. No spinal canal or neural foraminal stenosis. Mild facet arthropathy.L4-L5: No significant disc disease. No spinal canal or neural foraminal stenosis. Moderate bilateral facet arthropathy.L5-S1: No significant disc disease. No spinal canal or neural foraminal stenosis. Advanced bilateral facet arthropathy. Artifact related to hardware limits assessment; however previously seen synovial cysts on the left are not clearly appreciated and presumably have decreased in size.Mild degenerative changes at the sacroiliac joints also noted.
1. Subcentimeter benign-appearing cystic structure involving the right dorsal epidural space at the L1-L2 level which is not seen on preoperative imaging from 2/14/2015. Finding is favored to represent a synovial cyst. There is mild facet arthropathy at this level with enhancement which is likely on a degenerative basis. Ligamentum flavum cyst or perhaps residual chronic blood products related to prior intervention are other less likely differentials. There is mild indentation of the right dorsal aspect of the thecal sac without significant central canal stenosis overall at this level.2. No significant spinal canal or neural foraminal stenosis. Multilevel facet arthropathy, advanced at the bilateral L5-S1 level.