Male, 74 years old, with history of squamous cell lung cancer and known brain metastasis, admitted with altered mental status and hypoglycemia in the setting of vomiting, now extubated but persistently confused and altered. Subtle restricted diffusion is seen involving the splenium of the corpus callosum with no evidence of associated mass effect, blood product or enhancement and minimal if any corresponding T2 signal abnormality.Scattered patchy areas of T2 hyperintensity are redemonstrated in both cerebral hemispheres, largely periventricular and particularly prominent in the periatrial regions. The appearance and number of these lesions have not significantly changed allowing for technical differences between the scans.A focus of enhancement within the inferior right cerebellar hemisphere is redemonstrated with minimal associated T2 hyperintensity. This lesion measures approximately 6 x 5 mm on the current study compared to 8 x 7 mm on the prior exam. No new pathologic parenchymal or extra-axial enhancement is clearly seen.An enhancing mass centered in the sella is not as well seen on the present study due to motion artifact but probably not changed significantly in the interval.No evidence of significant mass effect is demonstrated. No intracranial hemorrhage or abnormal extra-axial fluid collection is suspected. Ventricular system is within normal limits for size and morphology.
1. Mild restricted diffusion involving the splenium of the corpus callosum is seen. This finding carries a broad differential diagnosis including sequelae of metabolic or electrolyte derangements including hypoglycemia, ischemic injury, sequelae of seizure, a medication related phenomenon, and some viral infectious agents. Given the history, it is quite possible that this finding reflects injury related to hypoglycemia.2. Scattered additional areas of white matter signal abnormality, particularly prominent in the periatrial regions, are again seen. There has been no significant interval change in the size or number of these lesions. These may be related to chronic ischemic injury, though other etiologies including demyelination and treatment related effects may be contributing.3. An enhancing lesion in the right cerebellar hemisphere compatible with metastasis remains visible but has decreased in size relative to the prior examination. No new intracranial metastases are suspected.4. A sellar mass is redemonstrated showing no significant interval change.