Intrahepatic bile duct stones show typical sonographic changes on ultrasound, appearing as punctate or mass-like strong echoes within the liver, accompanied by acoustic shadows. These strong echoes are distributed along the intrahepatic bile ducts. The bile duct proximal to the stone may exhibit varying degrees of dilation, and the dilated intrahepatic bile duct, along with the accompanying portal vein, forms a parallel tube sign. Around the strong echoes of the stones, a narrow anechoic region can be seen encircling them, and the stones generally do not move with changes in body position. Intrahepatic bile duct stones can also cause thickening of hepatic parenchyma echoes and internal echo heterogeneity.