Central dot sign is seen in?

Ans is c i.e. Caroli's disease Caroli's disease is a rare congenital abnormality in which there is communicating cavernous ectasia of the intrahepatic biliary ducts. Caroli's disease is equivalent to type V choledochal cyst. It is commonly associated with congenital hepatic fibrosis and cystic lesions of the kidney.Patients present in late childhood or early adulthood with cholangitis. Ultrasound and CT shows cystic lesions within the liver. A central dot within the cystic lesions is specific for Caroli's disease. The central dot represents the poal vein surrounded by the dilated bile duct. Choledochal cyst A choledochal cyst is an isolated or combined congenital dilatation of the extrahepatic or intrahepatic biliary tree.