What is the differential diagnosis?
Superior division of MCA subacute infarct, tumour (primary glioma, or possibly metastasis), evolving infection (although involvement of the cortex is unusual).
Single image from a digitized non contrast CT of the brain demonstrates a low density region within the left frontal lobe involving both white matter and overlying grey matter which is indistinct. The basal ganglia are spared. There is only minor positive mass effect.