Fetal sonography and neonatal scintigraphy of a choledochal cyst.

A choledochal cyst, observed by ultrasound at 27 wk gestation and diagnosed at 36 wk gestation, was confirmed postpartum by [99mTc]DISIDA cholescintogram. Cystic dilatation of the common bile duct was proven by surgical excision and histological verification. Ultrasonography provides in utero diagnosis of choledochal cyst, often vital for successful management. Technetium-99m DISIDA imaging is a valuable companion for defining function of the cyst.