Final answer:
The term describing the sonographic appearance of a gallbladder filled with stones is 'wall-echo-shadow' (WES) sign, also known as a 'packed gallbladder'. It shows a layer of echoes with acoustic shadowing on ultrasound.
Step-by-step explanation:
The term to describe the sonographic appearance of a gallbladder (GB) packed with stones is "wall-echo-shadow" (WES) sign or "packed gallbladder". This occurs when the gallbladder lumen is filled with so many gallstones that the stones create a layer of echoes on ultrasound, which results in a characteristic appearance. Beyond the stones, there is an acoustic shadowing that prevents the deeper structures from being visualized. When there is such a high number of gallstones, they can pack together, giving the sonographic impression of a solid mass rather than separate stones, hence the term 'packed' gallbladder.