There is a 14 x 13 mm region of abnormal signal lateral to the left lateral ventricle trigone, probably deep to the left supramarginal gyrus and posterior end of superior temporal gyrus, involving white matter but not clearly involving cortex. This lesion demonstrates mildly heterogeneous T2 hyperintensity that contains internal tiny foci of low T2 signal, and high signal on the DWI without corresponding high or low ADC values.
On the CT brain this region may have subtle increased density, while on the perfusion imaging performed at that time there is a corresponding focus of elevated cerebral blood volume (CBV). No definite enhancement within the lesion on the arterial phase images from the CT angiogram circle of Willis.
Conclusion: Although a subacute infarct is the most likely clinical diagnosis, on limited imaging sequences available there is a differential diagnosis of neoplasia.