Preoperative planning for brain tumor. History of a left temporal AVM treated with radiation. There is a heterogeneous left supratentorial and infratentorial lesion with associated cystic compartments, some of which contain fluid-fluid levels suggestive of hemorrhage. There is also surrounding vasogenic edema in the left cerebellar hemisphere. There is marked effacement of the fourth ventricle and dilatation of the third and fourth ventricles, which have increased in size slightly. There is also marked mass effect upon the brainstem. There is also a similar contiguous heterogeneous lesion within the left temporal and occipital lobes with surrounding vasogenic edema. There is no herniation. There are skin-based fiducial markers.
Presurgical planning MRI shows a complex mass in the left cerebellar hemisphere with associated obstructive hydrocephalus and a similar complex mass in the left temporo-occipital region. These lesions may represent radiation necrosis and perhaps vascular malformations with associated hemorrhage.