Gallstones. In this ultrasound example, the gallbladder is packed with multiple small calculi. There is ‘acoustic shadowing’ beyond the calculi. You will note that the sonographer has annotated the image with ‘Murphy sono -ve’, by which they mean that the patient was not tender when the ultrasound probe was placed over the gallbladder. Finding that a patient is sonographically Murphy’s positive is a helpful sign when trying to confirm a diagnosis of acute cholecystitis.