Clinical question: Incisional drainage. Signs and symptoms: Incisional drainage. Pre and post enhanced brain MRI:Examination demonstrates significant interval increased size of postoperative fluid collection in the soft tissues of lower back extending from L2-L3 disc level inferiorly to L5-S1 level. It measures approximately 106 mm in cranial cephalad compared to prior study measurement of 55. It also measures approximately 45 x 51 mm in transaxial dimensions larger than prior study. Findings demonstrate no mass effect on the thecal sac. There is no associated signal abnormality of displaced musculature or the bony structures adjacent to this collection. On post enhanced images there is expected enhancement of surrounding soft tissues to this collection. Possibility of an infectious process cannot be entirely excluded however the collection is amenable to direct aspiration if clinically an infectious process is suspected. There is redemonstration of tethered cord without definitive evidence of any change since prior exam.Post enhanced images demonstrate dural thickening and enhancement at the point of termination of the cord at S1 and S2 level which also surrounds the tethered cord. This finding highly suggestive of postoperative enhancement.Immediately superior to this level however there is no convincing evidence of left meningeal enhancement. Previously scans were performed without intravenous contrast and comparison cannot be made.
1.Interval increased extradural fluid collection in the soft tissues of lower back in the midline as measured above. There is enhancement of surrounding soft tissues and including the rim of fluid collection which could be within expected postop changes. If there is clinical concern for infection direct aspiration is recommended.2.Dural thickening and enhancement at the point of termination of the cord at S1-S2 level is believed to represent a postoperative finding and no detectable abnormal enhancement of the leptomeninges superior to this level.