Abdominal CSF pseudocyst secondary to ventriculoperitoneal shunt: diagnosis by computed tomography in two cases.

Two cases are presented in which the preoperative diagnosis of abdominal cerebrospinal fluid pseudocyst was made by computed tomography (CT). The collection can be well outlined by this method, and measurement of density values characterizes the contents as a water density; the relationship of portions of the shunt catheter to the pseudocyst can be demonstrated as well. It is suggested that, in a patient with a ventriculoperitoneal shunt who develops abdominal signs or symptoms, CT can provide the definitive diagnosis of this entity.