History of lung cancer with brain metastases. Pretreatment planning for stereotactic radiosurgery. Post surgical changes from prior right frontal craniotomy. Redemonstration of a cystic lesion containing a fluid fluid level and susceptibility artifact compatible with hemorrhage in a surgical resection/biopsy cavity. There is residual nodular peripheral enhancement as seen on the prior MRI. In aggregate this measures 2.3 x 1.9 cm in axial dimension. This is associated with stable surrounding decreased T1 signal suggestive of edema as well as local mass effect with effacement of the overlying sulci.The ventricles and basal cisterns are normal in size and configuration. The expected intracranial vascular flow voids are present. The paranasal sinuses are clear. The visualized mastoid air cells are grossly clear.
Examination for treatment planning. No significant interval change in cystic cavity with peripheral nodular enhancement at the right frontal operculum compatible with residual tumor .