This is particularly helpful for looking at the structures inside the head and particularly for the drainage system for cerebral spinal fluid to make sure there is no blockage and also for any tumours within the brain. It can be helpful to determine whether there is any raised pressure within the brain also. In younger children it involves an anaesthetic and in older children they just need to lie still inside the machine, which can be quite noisy. It can be a helpful investigation in certain circumstances in children who are presenting with vomiting for instance.