Gallbladder Ultrasound Examination

Ultrasound of the Liver

• Indications: Suspected focal or diffuse liver lesions, jaundice, abnormal liver function tests, right upper quadrant pain or mass, hepatomegaly, suspected portal hypertension, staging of known extrahepatic malignancy (though superseded by CT for patients over 30), pyrexia of unknown origin (though superseded by CT), real-time image guidance for biopsy needle placement, assessment of portal vein, hepatic artery, or hepatic veins, assessment of patients with surgical shunts or TIPS procedures, and follow-up after surgical resection or liver transplant
• Contraindications: None
• Patient Preparation: Fasting or restriction to clear fluids, if gallbladder also being studied
• Equipment: 3-5 MHz transducer, contact gel. Appropriate preset protocol selection depending on machine type, manufacturer, and patient factors
• Technique: Patient supine, time-gain compensation for uniform reflectivity throughout the right lobe, suspended inspiration, longitudinal scans from epigastrium or left subcostal to right subcostal regions (transducer angled cephalad), transverse scans subcostally to visualize entire liver; additional scans (intercostal, longitudinal, transverse, oblique) if necessary when visualization is incomplete; quiet respiration or real-time scanning during quiet respiration if breath-holding is not possible for visualization, or left lateral decubitus if incomplete visualization still occurs, contrast agents for contrast-enhanced ultrasound to characterize focal liver lesions (similar to contrast-enhanced CT or MRI) using specialized ultrasound machine software and low mechanical index scanning for quick contrast bubble bursting prevention. Images recorded after bolus injection of contrast agent with saline flush
• Advantages: Feasible even in presence of impaired renal function.
• Disadvantages: Limited to single lesion visualization per pass

Additional Views

• Hepatic Veins: Best visualized using transverse intercostal or epigastric approach during inspiration; real time, hepatic vein walls do not have increased reflectivity compared to normal liver parenchyma; normal hepatic vein waveform is triphasic, reflecting right atrial pressures; Power Doppler may be used to examine flow within hepatic IVC segment.
• Portal Vein: Longitudinal view using oblique subcostal or intercostal approach; normal portal vein walls have increased reflectivity compared to liver parenchyma; normal portal vein blood flow is towards liver; usually continuous flow, but velocity may vary with respiration.
• Hepatic Artery: Traced from the celiac axis (recognizable by "seagull" appearance of the origins of common hepatic and splenic arteries) with normally forward flow throughout systole and diastole, with a sharp systolic peak

Common Bile Duct and Spleen

• Spleen Size: Measure in all cases of suspected liver disease or portal hypertension; normal adult spleens usually measure 12cm or less in length, and less than 7 cm × 5 cm in thickness, "eyeballing" (measurement of longest diameter) is common method. Children: splenomegaly suspected if spleen is over 1.25 times the length of the adjacent kidney
• Common Bile Duct: Patients suspected of having gallstones or right upper quadrant pain, jaundice, fever of unknown origin, acute pancreatitis, assessing gallbladder function, guided percutaneous procedures should be evaluated
• Contraindications: None
• Patient Preparation: Fasting for at least 6 hours, preferably overnight, water is permitted
• Equipment: 3-5 MHz transducer, contact gel, appropriate preset protocol, factors including machine type, manufacturer, patient habitus, and positioning, or ultrasound stand for anterior gallbladder
• Technique: supine positioning; gallbladder location by tracing from the right portal vein to the gallbladder fossa; visualization around the long axis and transversely from the fundus to the cystic duct; rescanning in left lateral decubitus or erect positions for improved stone identification; head-down tilt may aid neck and cystic duct visualization; normal gallbladder wall thickness should not exceed 3 mm

Ultrasound of the Gallbladder and Biliary System

• Indications: suspected gallstones, right upper quadrant pain, jaundice, fever of unknown origin, acute pancreatitis assessing gallbladder function; guided percutaneous procedures
• Contraindications: None
• Patient Preparation: fasting for at least six hours, preferably overnight, water is permitted
• Equipment: 3-5 MHz transducer, contact gel, appropriate protocol, factors including machine type, manufacturer, patient habitus, and positioning, or stand-off for anterior gallbladder,

Ultrasound of the Pancreas

• Indications: suspected pancreatic tumor, pancreatitis or its complications, epigastric mass, epigastric pain, jaundice, facilitate guided biopsy and/or drainage
• Contraindications: None
• Patient Preparation Nil by mouth, preferably overnight
• Equipment 3-5 MHz transducer, contact gel, appropriate protocol, factors including machine type, manufacturer, patient habitus, and positioning (or stand-off for thin patients).
• Technique: Patient supine; pancreas located anterior to splenic vein in transverse epigastric scan; transducer angled transversely and obliquely to visualize head and tail; tail visualization using spleen as acoustic window; longitudinal epigastric scans may be useful; pancreatic parenchyma reflectivity increases with age, equaling liver reflectivity in young adults