11-year-old female with new onset seizures, hypodense area noted on outside hospital CT as well as abnormality University of Chicago stealth MRI performed last Friday. Redemonstrated is an ill-defined T2 hyperintense lesion primarily involving the right temporal lobe. The current diagnostic FLAIR technique better demonstrates its involvement of nearly the entire right temporal lobe as well as a portion of the immediately subjacent inferior right frontal lobe. As before abnormality is also noted in the posterior medial right thalamus. There is matching restricted diffusion with ADC hypointensity within these same regions. There is a also tiny focus of T2 hyperintensity involving the medial right frontal lobe gyrus, also with restricted diffusion and ADC hypointensity. Better defined by FLAIR technique is a very small focus of T2 hyperintensity within the anterior left temporal lobe just lateral to the temporal horn, which unfortunately lies in a region obscured on diffusion imaging secondary to skull base artifact. There is no susceptibility hypointensity to suggest the presence of hemorrhage. Also better defined by FLAIR technique is sulcal T2 hyperintensity, primarily involving right hemispheric sulci, which correlates with previously documented enhancement, with thickening of the right tentorium.
The constellation of abnormal MRI imaging features, superimposed on lesional locations (now also including the left temporal lobe), are most consistent with encephalitis/meningitis. Other inflammatory or neoplastic etiologies are felt to be less likely.