Nausea/vomiting, weakness, history of metastatic breast cancer with brain mets, new cerebellar edema on CT head. Exam is mildly limited by motion artifact, particularly on postcontrast imaging. As compared to MRI on 11/4/2016, there has been interval development of edema in the bilateral cerebellar hemispheres and vermis, right greater than left. There is associated mass effect including effacement of the fourth ventricle, anterior displacement of the brainstem, and crowding in the posterior fossa. There is mild enlargement of the ventricular system related to obstruction. There is mild increase in nodular enhancement surrounding the right cerebellar resection cavity as compared to the most recent prior MRI. Susceptibility sensitive sequence is nondiagnostic due to motion degradation.Enhancing lesions in the right anterior aspect of the pons and right occipital lobe are again seen and are not appreciably changed in size or MR characteristics since the recent study. There is additional punctate nonspecific enhancement along the right corona radiata. No new metastatic lesions are appreciated. There are unchanged postoperative findings of a posterior craniotomy and left frontal craniotomy with left frontal encephalomalacia.
1. Fairly rapid increase in nodular enhancement surrounding the cerebellar resection cavity and marked increase in cerebellar edema. Given their relatively rapid development, these findings may be related to treatment effect. Infection/encephalitis can be considered in the appropriate clinical setting. Rapid progression of metastatic disease is much less likely.2. Mass effect associated with cerebellar edema resulting in effacement of the fourth ventricle, mild interval enlargement of the ventricular system, and increased crowding in the posterior fossa.3. Right pontine lesion, right occipital lesion, and additional tiny enhancing foci are not significantly changed from the most recent prior MRI.