The liver, gallbladder, biliary tract, duodenal papilla, and pancreas should be examined with a high-frequency transducer, and, because these structures are in the cranial abdomen, it is usually best to use a curved-array transducer with a small footprint.
Ultrasonography is useful for estimating hepatic size and evaluating internal architecture (including portal, venous, arterial, and biliary vasculature; echogenicity; and echotexture). Size, wall thickness, and contents of the gallbladder, as well as size of the bile ducts, can also be assessed. Ultrasonography is also helpful for differentiating chronic injury (eg, cirrhosis, end-stage chronic inflammatory disease) from acute liver injury based on the size, shape, and internal architecture of the liver parenchyma.2
The gallbladder wall and contents can be assessed for cholecystitis, cholelithiasis, and mucoceles via ultrasound. Ultrasound-guided tissue sampling of the liver parenchyma and cholecystocentesis is safe and often necessary due to the nonspecific nature of imaging findings.3-6