Furthermore, excretion of hepatobiliary contrast and opacification of the biliary ducts and gallbladder provide additional information regarding the site and etiology of obstruction, as well as liver function [67-69]. US Abdomen Patients with elevated ALP suspected to be liver in origin and no alternative etiology should undergo transabdominal US to assess for dilated intra- or extrahepatic ducts and gallstones as the possible cause. Gallstone disease is prevalent with approximately 10% of adults having cholelithiasis and approximately 500,000 cholecystectomy operations performed annually [70]. Approximately 18% of adults undergoing cholecystectomy have choledocholithiasis [71,72]. Although abdominal US has a low sensitivity for detection of choledocholithiasis, in part related to frequent overlying bowel gas, it has high specificity [65]. When biliary obstruction is identified on abdominal US, frequently dynamic contrast-enhanced CT, MRI, or CEUS is required for further evaluation of the cause and possibly procedure planning. The absence of gallstones or choledocholithiasis suggests a nongallstone etiology and a normal caliber of the extrahepatic bile duct suggests intrahepatic cholestasis [71-73]. US Abdomen with IV Contrast For initial imaging, there is currently no role for CEUS in the evaluation of cholestasis. CEUS has been assessed for the evaluation of liver fibrosis, which may nonspecifically elevate ALP, and is used in the characterization of potentially obstructing hepatic lesions. Similar to CT and MRI perfusion techniques, CEUS uses contrast media transit characteristics to make deductions about liver hemodynamics that relate to the presence and severity of liver fibrosis and for the characterization of hepatic lesions. US Duplex Doppler Abdomen There is debate regarding the diagnostic value of adding Doppler US to the US abdomen examination for initial imaging.
Abnormal Liver Function Tests. Furthermore, excretion of hepatobiliary contrast and opacification of the biliary ducts and gallbladder provide additional information regarding the site and etiology of obstruction, as well as liver function [67-69]. US Abdomen Patients with elevated ALP suspected to be liver in origin and no alternative etiology should undergo transabdominal US to assess for dilated intra- or extrahepatic ducts and gallstones as the possible cause. Gallstone disease is prevalent with approximately 10% of adults having cholelithiasis and approximately 500,000 cholecystectomy operations performed annually [70]. Approximately 18% of adults undergoing cholecystectomy have choledocholithiasis [71,72]. Although abdominal US has a low sensitivity for detection of choledocholithiasis, in part related to frequent overlying bowel gas, it has high specificity [65]. When biliary obstruction is identified on abdominal US, frequently dynamic contrast-enhanced CT, MRI, or CEUS is required for further evaluation of the cause and possibly procedure planning. The absence of gallstones or choledocholithiasis suggests a nongallstone etiology and a normal caliber of the extrahepatic bile duct suggests intrahepatic cholestasis [71-73]. US Abdomen with IV Contrast For initial imaging, there is currently no role for CEUS in the evaluation of cholestasis. CEUS has been assessed for the evaluation of liver fibrosis, which may nonspecifically elevate ALP, and is used in the characterization of potentially obstructing hepatic lesions. Similar to CT and MRI perfusion techniques, CEUS uses contrast media transit characteristics to make deductions about liver hemodynamics that relate to the presence and severity of liver fibrosis and for the characterization of hepatic lesions. US Duplex Doppler Abdomen There is debate regarding the diagnostic value of adding Doppler US to the US abdomen examination for initial imaging.