History of brain metastasis, from tonsillar squamous cell carcinoma. Status post resection and stereotactic radiosurgery. The postcontrast sequences are limited by patient motion.There are findings related to previous surgery and stereotactic radiosurgery in the inferior left parietal lobe, which remain unchanged with no perceptible contrast enhancement, accounting for expected overlying postcraniotomy dural contrast enhancement and thickening. The associated surrounding white-matter T2-hyperintense signal has very gradually minimally increased along the inferior aspect of the lesion, best seen on axial image #21 of series #501 and coronal image #36 of series #901.There is no new focal brain lesion. There is no acute infarct or acute intracranial hemorrhage. The ventricles, sulci and cisterns are symmetric and unremarkable. There is no mass-effect, midline shift or brain herniation. Major intracranial vascular flow voids are preserved. The mastoid air cells are clear. Left maxillary retention cysts and bilateral maxillary and ethmoid sinus mucosal thickening remain unchanged. There is increased mucosal thickening in the left frontal sinus which is nonspecific.
Post contrast sequences are limited by patient motion. There are posttreatment findings in the left parietal lobe but no contrast enhancement. These are unchanged since the previous examination except for minimal increase in the surrounding T2 hyperintensity, which is nonspecific and may represent evolving posttreatment changes. Continued follow-up is recommended. 