Brain bleed. There is a heterogeneous intermediate to high T1 signal and mixed low and high T2 signal lesion centered in the left middle cerebellar peduncle with diffuse central and peripheral susceptibility effect, which measures up to 20 mm. There is surrounding vasogenic edema. There is mild effacement of the fourth ventricle, but the third and lateral ventricles are not particularly enlarged. There is no evidence of acute infarct. There is no abnormal intracranial enhancement. There is no midline shift or herniation. The orbits, skull, and scalp soft tissues are grossly unremarkable. There is a retention cyst in the left maxillary sinus.
Findings most suggestive of a recently hemorrhagic left middle cerebellar peduncle cavernous malformation with associated developmental venous anomaly.