 Redemonstration of an enhancing dural based metastatic lesion along the left frontal convexity which appears intimately associated to the cortical surface; there may be subtle underlying parenchymal invasion. The lesion now measures up to 1.4 cm in thickness, previously 7 mm, and causes mass effect on the underlying frontal lobe with new low T1 signal within the surrounding white matter consistent with vasogenic edema. The lesion extends along the dura anteriorly and inferiorly involving the left temporal convexity with mild mass effect of the underlying temporal lobe. There is non-suppression of CSF on the FLAIR sequence along the frontal cortical sulci which may represent congestion or leptomeningeal disease. There is also minimal leptomeningeal enhancement in this region. There is susceptibility associated with the extra-axial lesion as well as trace susceptibility involving the left frontotemporal sulci. No frank intraperitoneal hematoma is evident. There otherwise is no evidence of acute infarct or intracranial hemorrhage. Mild nonspecific periventricular and subcortical abnormal T2 signal is again noted. There is no midline shift or herniation.The low T1 signal, low T2 signal, and enhancing lesion within the left calvarium overlying the dural metastasis appears increased in size in the longitudinal dimension. Although there is no large destructive component, CT would be more sensitive in evaluating for bony destruction. There is mildly increased thickening and enhancement involving the left temporalis muscle and along the left scalp overlying the lesion in the bone.
1. Interval progression of disease with increasing size of the dural based metastatic lesion with new mass effect and vasogenic edema within the left frontotemporal lobe, larger calvarial lesion, and increased scalp thickening. 2. Susceptibility effect is noted with above lesion including within the adjacent left frontoparietal sulci related to mineralization and/or blood products. Consider noncontrast head CT to exclude the possibility of acute hemorrhage associated with this lesion.