Ventriculoperitoneal shunt function: evaluation by sonography.

The function of ventriculoperitoneal shunts was evaluated by ultrasonography in 17 patients. In 10 of 15 patients with properly functioning shunts, a small amount of free intraperitoneal fluid was found. However, absence of demonstrable fluid did not reliably indicate shunt malfunction. No asymptomatic patients had large amounts of ascites or loculated fluid collections, both of which were considered pathologic in shunt patients.