 Redemonstrated is patchy ill-defined enhancement and increased T2/FLAIR signal in the anterior temporal lobes with no significant change from the prior exam. Perfusion imaging in this area is unreliable due to susceptibility effect from the skull base. MR spectroscopy is also complicated by the enhancing tissue being in close proximity to the skull base. A small voxel was utilized and, by necessity, only partially included the enhancing tissue. Nevertheless, the spectrum does contain diagnostic information and shows a reduction of the major metabolic peaks (choline, creatinine, and NAA). In addition, there are features suggestive of a small amount of lipid and possibly a lactate doublet.The ventricles and sulci are prominent, consistent with mild age-related volume loss. The basal cisterns remain patent. There is no midline shift or mass effect. There is a similar pattern of scattered punctate foci and confluent areas of abnormal T2/FLAIR hyperintensity within the periventricular and subcortical white matter, which are nonspecific but may represent mild chronic small vessel ischemic changes and/or post treatment changes. There is no new pathological enhancement. A left frontal developmental venous anomaly is again incidentally noted. There is no diffusion abnormality. No extra-axial fluid collection is identified.Normal flow-voids are demonstrated in the major intracranial vascular structures. The midline structures and craniocervical junction are within normal limits. Again seen is a left maxillary sinus mucosal retention cyst.
Stable patchy ill-defined areas of enhancement in bilateral temporal lobes. The location, symmetry, and information obtained from spectroscopy favor radiation treatment-related tissue injury rather than metastatic involvement.