Figure 1.

A 56-year-old gentleman with a history of type 2 diabetes mellitus presented with a 5-day history of progressive fatigue, malaise, and subjective fever. On the day prior to presentation, he developed severe headache and had significant change in mental status. His examination was notable for confusion and mild right arm weakness. Noncontrast CT (A) demonstrates a left frontal mass at the gray-white junction with surrounding vasogenic edema. On magnetic resonance imaging (MRI), there is subfalcine herniation. T2 (B) and T1 postcontrast (C and D) maps demonstrate a heterogeneous ring enhancing, T1-hypointense, T2-hyperintense fluid collection. There is thinning of the periventricular rim. The central nonenhancing portion demonstrates restricted diffusion (E) and is hypointense on apparent diffusion coefficient (ADC) images (F).