Challenges in Ultrasound of the Gallbladder and Bile Ducts: A Focused Review and Update.

Although ultrasound is the initial imaging modality of choice in patients with right upper quadrant pain or suspected biliary obstruction, a number of challenges in clinical practice limit its utility as a stand-alone imaging modality. This article presents a focused review of gallbladder and biliary ultrasound, highlighting current knowledge gaps, emerging applications, and directions for further study. The authors cover selected topics including acute cholecystitis, cystic artery velocity, gallbladder polyps, contrast-enhanced ultrasound, and incidental biliary duct dilatation.