Does a ct scan show if there is abnormal pressure in the skull?

Sometimes: Pressure abnormalities in the skull such as non-communicating hydrocephalus or low CSF pressure can sometimes be seen indirectly on a ct of the head (usually when chronic and or severe). However, history and physical examination are often better at letting us know when "pressure abnormalities" are of concern and can sometimes be measured directly when a spinal tap is performed.

Yes it can but: Signs of increased intracranial pressure (icp) with dilated ventricles & even bone changes with chronicity, can be absent on ct early on. Suspicion & with other signs & symptoms, treatments must be enacted much more urgently.