36-year-old female status post Chiari decompression complicated by CSF leak subsequently repaired started on high dose Bactrim IV, now with persistent nausea and vomiting. Evaluate for any bleed or reason for persistent nausea/vomiting. Postoperative changes status post suboccipital craniectomy are again evident. An ovoid fluid density structure is seen superficial to the operative site within the subcutaneous tissues, which appears more prominent compared to the prior CT, grossly unchanged from recent MRI. No definite communication with the posterior fossa is evident. No acute hemorrhage or extra-axial fluid collections are evident. A new focus of hypodensity is seen in the postero-medial aspect of the right cerebellar hemisphere, corresponding to focus of restricted diffusion on recent MRI. The remainder of the cerebral and cerebellar hemispheres demonstrate normal morphology and density. The ventricles are midline, with normal morphology and volume. No abnormal extra-axial fluid collections are evident.Apart from postoperative changes status post suboccipital craniectomy, the remaining calvaria and osseous structures are intact. The visualized paranasal sinuses and mastoid air cells are normally pneumatized.
1. Subcutaneous fluid collection superficial to the operative site, with no clear communication with the posterior fossa to suggest a pseudomeningocele.2. Subacute infarction in the right cerebellar hemisphere.