Hydrocephalus

‘The basic approach to all hydrocephalus is the same: you have to make a judgement whether the size of the ventricles is “normal” or not, for the individual patient.’ However, two broad groups of patients can be identified when looking for hydrocephalus in a brain CT scan in everyday clinical practice. The first group of patients are those whose hydrocephalus had already been diagnosed (hence they may have previous scans to compare with) and the second group are those patients that have had no previous imaging before. We will consider the second group first. Ventricular enlargement when gross is very easy to recognize on the CT scan (Fig. 4.1A), but the key question is whether it is under high pressure or not because hydrocephalus technically is ventriculomegaly associated with raised intracranial pressure.