Generalized diffuse cerebral oedema with loss of normal grey-white differentiation.
Hypoattenuation of the cerebral hemispheres, especially basal ganglia with sparing of the cerebellum, gives rise to the "white cerebellum sign".
Hyperdense falx cerebri, tentorium cerebelli, and subarachnoid spaces appear filled with "blood" relative to the brain parenchyma, giving the appearance of pseudosubarachnoid haemorrhage.
Marked significant mass effect with tonsillar and uncal herniation and slit-like effacement of the ventricles. No midline shift. No acute intracranial haemorrhage.