31 year old man s/p microdiscectomy at L5-S1 and blood patch with persistent headache. Five lumbar type vertebral bodies are presumed to be present. Vertebral body heights are within normal limits. There is mild straightening of the normal lumbar lordosis, otherwise alignment is within normal limits. Bone marrow signal is benign. The conus medullaris is normal in position.L1-L2: No significant disc disease. No spinal canal or neural foraminal stenosis.L2-L3: No significant disc disease. No spinal canal or neural foraminal stenosis.L3-L4: No significant disc disease. No spinal canal or neural foraminal stenosis.L4-L5: There is a mild disc bulge without significant spinal canal or neural foraminal stenosis.L5-S1: There are postoperative findings of S1 left hemilaminectomy and L5/S1 partial discectomy. There is a 12 x 10 mm focus of disc extrusion which demonstrates high T2 signal suggesting a new left paracentral extruded fragment. There is thick peripheral enhancement surrounding this extruded fragment which is greater than the area of T2 signal abnormality, likely representing postoperative scar formation from recent discectomy. This protrusion causes effacement of the anterior thecal sac, left lateral recess, and compression of the left S1 nerve root.Additionally, there is a defect in the dura along the left posterolateral aspect of the spinal canal (series 6, image 42) with fluid extending through the epidural space and laminectomy into the left paraspinal muscles forming a well-defined 23 x 23 mm collection. There is circumferential CSF signal extending superiorly along the epidural space to the level of T12/L1 and extending inferiorly to S2. This epidural fluid causes mild mass effect on the anterior thecal sac. The paraspinal soft tissues are otherwise within normal limits.
1.Fluid extending from the left posterolateral aspect of the thecal sac at the surgical site through the laminectomy into the left paraspinal muscles and also circumferentially in the epidural space from T12/L1 level to S2. This finding is most compatible with postoperative CSF leak at the surgical site.2.New/recurrent left paracentral L5/S1 disc extrusion with resultant sinal stenosis, lateral recess compromise and impingement on the left S1 nerve root.