What is the diagnosis here?
This is intracerebral haemorrhage or a haemorrhagic stroke.
What has happened in the ventricles?
They look slightly enlarged, but this can be a normal finding for the patient's age. However if you look in the occipital poles, there is a fluid-fluid level as hyperdense blood collects in the hypodense CSF. This means that there is now in intraventricular bleed. Recurrent scans may be required as blood lining the ventricles can inhibit CSF reabsorption and lead to hydrocephalus.
Hyperdense left basal ganglia with surrounding oedema and mild mass effect. Layering of dense material in both ventricles.
Consistent with acute intracerebral haemorrhage.