90% cases are caused by gallstones, especially stones embedded in the neck of gallbladder. Pay attention to whether there are signs of stones in the neck of gallbladder during examination. In cholecystitis, the gallbladder wall thickens, which can form a "bilateral sign" of annular low voice band due to edema. The whole gallbladder is swollen and there are deposits in the capsule. When the probe touches the gallbladder, the patient complains of severe pain, which is called Murphy's sign of ultrasound. When the inner wall of the capsule is irregular and discontinuous, and there are a lot of flocs in the capsule, it indicates suppurative or gangrenous cholecystitis. When cholecystitis is perforated, the echo of the cyst wall is interrupted and there is no echo area around it. Chronic cholecystitis can thicken the cyst wall and make the cyst cavity smaller.
Typical features of gallstones include: ① strong echo in gallbladder or gallbladder area; (2) Strong echo drags the end shadow; ③ Strong echo can move with body position. Sediment-like stones can be deposited into layers under gravity.