There is a 35 x 44 x 44 mm slightly lobulated, avidly rim enhancing lesion in the left parieto-occipital region. The lesion demonstrates a hypointense rim on T2 imaging, as well as marked central diffusion restriction. Significant amount of T2/FLAIR hyperintense signal abnormality surrounds the lesion, with mass effect causing effacement of overlying sulci. No significant midline shift.
Spectroscopy demonstrates metabolite depletion and high lactate peaks within the central portion. This lesion demonstrates diffusion restriction and slight contrast enhancement.
Large left parieto-occipital rim-enhancing lesion with surrounding vasogenic oedema. Although potentially a metastasis (known primary colorectal carcinoma) the marked internal diffusion restriction and spectroscopy findings raise concern for a brain abscess.