Ultrasonography

Ultrasonography

Transabdominal ultrasonography (USG) ( Figure 71.7 initial imaging modality of choice as it is accurate, readily John Benjamin Murphy , 1857–1916, surgeon, Mercy Hospital, Chicago, IL, USA. operator dependent and may be compromised by excessive body fat and intraluminal bowel gas. The size of the gall - bladder and presence of stones or polyps can be determined. Acute calculous cholecystitis is diagnosed radiologically (sensi - tivity 90–95%) by thickening of the gallbladder wall (>3 /uni00A0 mm), presence of pericholecystic fluid or direct tenderness when the probe is pushed against the gallbladder (ultrasonog raphic Murphy’s sign). Additionally , the presence of inflamma tion around the gallbladder, the size of the CBD and, occasionally , the presence of stones within the extrahepatic biliary tree can be determined. ) is the In a patient with obstructive jaundice, USG can iden - tify intra- and extrahepatic biliary dilatation, the level of the obstruction and the cause of the obstruction – stones, com - mon hepatic duct or CBD, lesions within the wall of the CBD suggestive of cholangiocarcinoma, gallbladder cancer or mass lesions in the pancreatic head.

Figure 71.6 Gas in gallbladder and gallbladder wall ( Clostridium perfringens infection). Emergency cholecystectomy is indicated. Figure 71.7 Ultrasound examination. Gallstones in neck of gallbladder with acoustic shadowing.