 The previously seen subcortical high T2 signal in the right parietal lobe has resolved. However, a punctate focus of susceptibility effect remains in this location. There is a new ill-defined area of T2 hyperintensity involving the left posterior cingulate gyrus and possibly part of the splenium of the corpus callosum. There is no mass-effect, restricted diffusion, or susceptibility associated with this new lesion. A smaller focus of high T2 signal in the right superior frontal gyrus as well as other small periventricular foci of high T2 signal are unchanged. There is no evidence of restricted diffusion. Encephalomalacia involving the right cerebellar hemisphere is unchanged. There is no midline shift or herniation. There is mild maxillary sinus mucosal thickening. The skull, paranasal sinuses, and scalp soft tissues are unremarkable.
Interval resolution of T2 signal abnormality in the right precentral gyrus seen on the prior study, with a persistent small focus of susceptibility in this location. Scattered smaller foci of periventricular high T2 signal remain, and there is a new area of T2 signal abnormality involving the left posterior cingulate gyrus and possibly part of the splenium of the corpus callosum without mass-effect, restricted diffusion, or susceptibility in this new lesion. The apparent interval resolution of a previously seen lesion, in the absence of any medical or pharmacologic intervention, would argue against metastatic disease. The differential diagnosis therefore remains quite broad and includes inflammatory, infectious, autoimmune, and vascular etiologies along with medication effect. 