Two aspects of hydrocephalus can be observed on CT: the first aspect is the enlargement of the ventricles; the second aspect is the compression of the brain tissue. However, it needs to be distinguished from other types of diseases, such as atrophy, which may also appear similar to hydrocephalus, so further tests are needed to determine whether it is hydrocephalus or atrophy. In common hydrocephalus CT, enlarged ventricles can be seen, including the third ventricle, lateral ventricle, fourth ventricle, etc. The brain tissue may also show loss of sulci and gyri or relative hypodensity. It may also show edema, especially in the frontal horn and triangle, and in more severe cases of hydrocephalus, brain displacement may also be seen.