Right frontal lobe ring enhancing lesion, centred at the grey-white junction, measuring 28 mm in maximal diameter and with marked surrounding vasogenic oedema and mass effect as described on the earlier CT.
The lesion has a well-defined T2 hypointense margin and demonstrates marked central diffusion restriction. A prominent lipid and lactate peak is noted on spectroscopy (not shown). Thin peripheral hypointensity seen on echoplanar sequence is complete and smooth.
Right maxillary sinus mucous retention cysts are noted as described on the previous CT. No evidence of sinusitis or mastoiditis is identified. Cavum septum pellucidum and vergae.
Conclusion:
The marked diffusion restriction and elevated lactate on MRS are most consistent with cerebral abscess.