Left cerebellar lesion, status post biopsy. There are postoperative findings related to left occipital approach stereotactic guided biopsy of the left upper cerebellar lesion. The lesion again presents as mildly T2 hyperintense, with small foci of intrinsic T1 signal likely related to minimal postprocedural blood product. The lesion measures up to 20 mm in maximum diameter and has not significantly changed in size from the prior exam. As before, the inferior margin of the lesion is sharply defined and distinct from the normal cerebellar parenchyma, whereas the superior margin is less well defined and seems to blend with the cerebellar folia. A small enhancing focus within the lesion is also unchanged. There is elevated rCBV and rCBF which correlates with this enhancing nodule, unchanged from prior. Once again, single and multi voxel spectroscopy of the lesion demonstrates elevation of choline and reduction of NAA within the lesion with an abrupt return to a normal pattern beyond the lesion margins.The brain parenchyma is otherwise normal. There is no other pathologic parenchymal or leptomeningeal enhancement. Incidentally noted developmental venous anomalies are present in the right parietal and left frontal lobes. The ventricles and basal cisterns are normal in size and configuration. There is no midline shift or herniation. The major cerebral flow voids are intact. There is trace fluid in the right mastoid air cells.
The lesion in the left upper medial cerebellar hemisphere has not significantly changed in size since the prior exam. A focus of enhancement internal to the lesion also remains unchanged. Elevated rCBV and rCBF is demonstrated associated with the enhancing nodule, similar to prior. Again, the spectroscopic assessment of the lesion reveals elevation of choline and reduction of NAA, similar to prior.