MRI confirmed these findings. The peripheral contrast enhancement around the lesion is irregular (sometimes referred to as furry). The degree of vasogenic oedema is less than one would expect for a cerebral abscess, which may be due to partial treatment and relatively chronic time-course.
MRS demonstrates a very high lactate peak.
Most convincing is the very pronounced restricted diffusion (DWI and ADC).
Features are consistent with an abscess, likely secondary to pachy / leptomeningitis which in turn was secondary to direct ascent of infection from the neck - probably from a thrombosed and infected emissary vein.