 The ventricles and sulci are prominent, consistent with mild age-related volume loss. However, there is enlargement of the lateral and third ventricles, out of proportion to the degree of sulcal prominence; this is grossly stable when compared to remote MRI from 2006. The basal cisterns remain patent. There is no midline shift or mass effect. There are scattered punctate foci of abnormal T2/FLAIR hyperintensity within the periventricular and subcortical white matter, which are nonspecific, slightly progressed from prior MRI. There is no pathological enhancement. There is no diffusion abnormality. No extra-axial fluid collection is identified.There is a multilobulated structure of CSF-signal extending medially and inferiorly from the medial right middle cranial fossa, immediately posterior to Meckel's cave, which was not seen on the previous study, measuring up to 1 cm (series 901, image 17). This structure appears contiguous with the adjacent subarachnoid space. No significant CT abnormality is seen in this location previously.Normal flow-voids are demonstrated in the major intracranial vascular structures. There is a partially empty sella. There is horizontal angulation of the clivus, resulting in flattening of the skull base, likely developmental.
1.No intracranial metastatic lesions are identified.2.Subcentimeter, multilobulated, CSF-signal intensity structure inferomedially adjacent to the right middle cranial fossa, not seen on prior MRI and without significant prior CT correlate. Given apparent contiguity with the adjacent subarachnoid space, this may represent an encephalocele. Consider MRI brain with thin cuts or CT through the skull base if further evaluation is warranted.3.Stable chronic disproportionate enlargement of the lateral and third ventricles, of uncertain clinical significance.