Clinical question:R/O hematoma or abscess. Signs and symptoms: Fever. Pre and post enhanced lumbar MRI:Examination is degraded due metallic hardware artifact from transpedicular screw placement for spinal fusion at L3 and L4 levels.Leading this limitation examination demonstrate interval diskectomy at L3 -- L4 and without evidence of residual disk herniation. A previously noted cystic lesion projecting anterior to the right articulating facet at L2 -- 3 is no longer identified and presumed surgically removed.Mild grade 1 anterolisthesis at L3 -- L4 appears a slightly more prominent than prior exam. There is subtle interval increase height of the disk space at this level secondary to disk fusion procedure.Transpedicular screws demonstrate evidence of complication in this the study. There is uniform mild T2 hyperintensity of L3 and L4 which may be artifactual since this appearance is not present on sagittal T2 stir series. Examination demonstrate no spinal stenosis. Post enhanced images although compromised due to metallic hardware artifact demonstrate no evidence of epidural collection to suggest presence of abscess.There is however mild dural thickening and enhancement at the surgical site which is within expected post operative change. There is a mixed-signal intensity collection posteriorly in the cutaneous and subcutaneous tissues at the surgical site at L4 with thin irregular rim of enhancement. This collection measures approximately 19 x 16-mm in transaxial dimensions. There is a linear signal void within this collection which could represent a drain. There is however no detectable extension of this finding beyond the collection and small hemorrhagic change could possibly have this appearance. The overall appearance of this finding is within expected postop change (correlate with timing of surgery). This collection is superficially located and can be aspirated for further analysis for underlying infection.
1.Expected postoperative changes of diskectomy and posterior fusion, transpedicular screw placement at L3 -- L4 levels as detailed. Mild grade 1 anterolisthesis is again identified. No evidence of spinal stenosis.2.No abnormal enhancement of the vertebral column to suggest an infectious process or abscess formation.3.Cutaneous and subcutaneous collection along the surgical path measuring at 19 x 16 mm size and with surrounding enhancement. This finding is within expected postop change however possibility of overlapping infection cannot be entirely excluded. The lesion is superficial and can be directly aspirated for further analysis.