Clinical question: Metastatic lung cancer, brain metastases, status post SRS to lesion. On immunotherapy now. Compared to prior exams and evaluate response to treatment. Signs and symptoms: Brain metastases. Pre and post enhanced brain MRI:Negative diffusion weighted series.Examination demonstrates stable chronic changes on the left anterior frontal paramedian tumor treatment with remaining encephalomalacia. Metallic artifact at this site partially obscures the region however beyond the region of artifact there is no detectable abnormal enhancement to suggest residual or recurrence of tumor.Multiple small foci of FLAIR hyperintensity with a small internal foci of enhancement noted in bilateral cerebral hemispheres and right cerebellum demonstrate significant interval improvement some with near complete resolution. On post contrast images there is a single punctate focus of enhancement in the right cerebellum measuring approximately 1.5 x 1.2 mm in transaxial dimensions consistent with a remaining metastatic disease with interval decreased since prior study measurement of 3.8 x 3.2 mm.None of the additional previously noted metastatic lesions in bilateral cerebral hemispheres or cerebellar hemispheres can be identified.A stable subcentimeter dural based focus of enhancement at the left jugulum sphenoidale demonstrate no significant change in size or enhancement and could represent a tiny dural based metastatic lesion or a benign extra-axial tumor such as a meningioma. This finding similar to prior exam appears to be at least partially within the left cavernous sinus.
1.Examination demonstrates significant interval improvement of metastatic brain lesions since prior study. Compared to prior exam there is only a single 1.5 x 1.2 mm (previously 3.8 x 3.2 mm) remaining enhancing metastatic lesion in the right cerebellum is detected. No additional metastatic lesions are visualized on the postcontrast series.2.Stable subcentimeter dural base enhancing lesion of the jugulum sphenoidale with partial extension into the left cavernous sinus is again noted.3.Stable focus of encephalomalacia without detectable enhancement in the left paramedian inferior frontal.