Male, 50 years old, with history of renal cell metastasis to the brain, surveillance imaging. Findings are redemonstrated compatible with right parietal craniotomy and perirolandic tumor resection. The posterior edge of the craniotomy flap remains posteriorly displaced relative to the native calvarium, similar to the prior exam. Minimal extra-axial fluid is seen beneath the craniotomy. A small hemosiderin stained resection cavity is seen containing small locules of late subacute blood product. The quantity of this blood product has diminished from the prior exam. Faint rim enhancement is seen around the resection cavity with more conspicuous curvilinear enhancement along the posterior margin of the cavity. This posterior enhancement is stable or mildly reduced relative to the prior exam. Of note, the tumor was predominantly nonenhancing on preoperative images.The degree of T2 hyperintensity surrounding the surgical bed has not significantly changed. At most, there is mild regional mass effect in the form of sulcal effacement. No additional suspicious areas of parenchymal signal abnormal or enhancement are seen. A focus of nonspecific T2 hyperintensity in the left frontal white matter is unchanged. No significant marrow abnormalities are detected. Mild mucosal thickening is seen in the maxillary sinuses.
Postoperative findings are again seen compatible with resection of a right perirolandic metastasis. Blood product within the resection cavity is decreasing and the extent of signal abnormality surrounding the surgical bed is unchanged. Nonspecific enhancement most notably along the posterior aspect of the resection bed is stable to reduced, and favored to represent postoperative change given that the preoperative tumor was largely nonenhancing.