51-year-old male with new onset right lateral thigh and calf pain, severe LBP. Evaluate for epidural hematoma status post L5-S1 revision laminectomy on 5/5/2016. Redemonstrated is mild developmental narrowing of the spinal canal. The vertebral body heights are within normal limits. There is loss of lumbar lordosis as well as minimal retrolisthesis of L5 on S1. Alignment is otherwise maintained. Bone marrow signal is benign. The conus medullaris is normal in position. There has been interval revision of a right L5-S1 discectomy, laminectomy and partial facetectomy. Residual tissue at the level of the L5-S1 posterior disc level and right lateral recess may represent disc protrusion and/or blood products and can be better assessed on follow-up studies. There are heterogeneous blood products at the right dorsal lateral L5-S1 laminectomy mostly in the paraspinous soft tissues.Heterogeneous T1/T2 signal involving the ventral epidural space beginning at the L4-5 level and extending to the S2 level is favored to represent engorged epidural venous plexus with superimposed blood products. There is resulting severe effacement of the thecal sac at the L5-S1 level which was not present on the previous MRI from 4/13/2016. More superiorly in the upper lumbar spine there is slight dorsal and leftward displacement of the cauda equina nerve roots which may be related to mild arachnoiditis although a CSF collection ventrally is not entirely excluded. There is no significant mass effect.Additional multilevel degenerative changes from L1-L2 through L4-5 are not significantly changed from the prior MRI, including disc desiccation, mild disc bulge, and central dorsal annular fissure at the L4-5 level without significant spinal canal or neural foraminal narrowing. Neural foraminal narrowing at the L5-S1 level is again noted bilaterally.Atrophic native kidneys with cysts noted. Left lower quadrant presumed transplant kidney partially imaged.
1.Postoperative changes of a right L5-S1 revision discectomy, laminectomy and partial facetectomy with some residual disc protrusion suspected involving the right lateral recess. Extent of residual disc can be better assessed on follow-up imaging, when immediate postoperative changes improve.2.Interval increasing heterogeneity of the anterior ventral epidural space at the L4-5 through S2 level which is favored to represent engorged epidural venous plexus with probable superimposed blood products. This results in severe effacement of the thecal sac at the L5-S1 level, which is new from the exam from 4/13/2016. If there remains suspicion for hematoma causing compression, recommend postcontrast imaging to better evaluate this lesion and confirm epidural venous plexus. 3.More superiorly in the lumbar spine there is slight dorsal and leftward displacement of the cauda equina nerve roots which may be related to mild arachnoiditis although a CSF collection ventrally is not entirely excluded. There is no significant mass effect and the significance of this finding is uncertain.