Abstract
The diagnosis of porencephaly by isotope cisternography is described. In the three cases presented, porencephaly was associated with non-resorptive hydrocephalus. The communicating hydrocephalus caused the isotope to enter the ventricular system and visualize the cyst, and the diagnosis of both disorders was established by RIHSA cisternography. The method is simple and non-traumatic and provides information about abnormalities which air may fail to demonstrate.