Non-contrast CT brain followed by volume acquisition from the vertex to the aortic arch with dynamic administration of intravenous contrast.
Subarachnoid haemorrhage is demonstrated in the perimesencephalic cistern and extending into both sylvian fissures and the anterior interhemispheric fissure. No other areas of intracranial haemorrhage. No intracranial mass. Ventricles and sulci are age-appropriate.