Clinical question: NSCLC with brain metastases status post SRS. In MRI to evaluate. Signs and symptoms: As above. Pre-and post enhanced brain MRI:No diffusion weighted abnormalities.Examination demonstrates internal significant decreased size of the left posterior temporal metastatic lesion measuring at approximately 3 mm size compared to prior study measurement of 8.8-mm. There is no residual surrounding edema but this finding.The second smaller metastatic lesion in the right frontal lobe seen on prior exam is no longer identified.There is also no detectable new metastatic lesions since prior exam.Flair and T2 weighted images demonstrate extensive periventricular and to a lesser degree subcortical foci of hyperintensity which are nonhemorrhagic and nonenhancing. Similar findings are also noted in bilateral thalami. Compared to prior exam there is minute internal progression of this finding. Differentials of chronic nonhemorrhagic small vessel ischemic strokes should be considered. This finding is also believed to be at least partially secondary to overlapping post radiation change.
1.Significant decreased size of a left posterior temporal metastatic lesion measuring at 3 mm compared to prior study measurement of 8.8-mm. Previously noted right frontal metastatic lesion is no longer present. No evidence of new metastatic lesions to brain, leptomeninges or the calvarium.2.Negative diffusion weighted images.3.Minute interval progression of periventriclar and subcortical flair hyperintensity which could represent a combination of chronic nonhemorrhagic small vessel ischemic strokes as well as post radiation change.