There is a ring-enhancing centrally hypoattenuating ovoid lesion within the white matter of the right occipital lobe, corresponding to the changes described on the recent non-contrast CT. The enhancing component measures 20 x 12 x 12 mm. There is mild perilesional vasogenic oedema and mild positive mass effect, with partial effacement of the occipital horn of the right lateral ventricle.
No further intra or extra-axial space-occupying lesion. No further abnormal focus of intracranial contrast enhancement. No CT evidence of ventriculitis.
The major dominant intracranial arteries and dural venous sinuses opacify normally.
IMPRESSION
Ring-enhancing centrally hypoattenuating lesion within the right occipital white matter with mild positive mass effect. The differential diagnosis is between a cerebral abscess and neoplasm. MRI with gadolinium is recommended.