Article

Upper abdominal ultrasound: what to assess

Upper abdominal ultrasound: liver, gallbladder, bile ducts, pancreas and spleen — technique, reference measurements, normal report, limitations and findings.

What it is and when to indicate it

Upper abdominal ultrasound focuses on the liver, gallbladder and bile ducts, pancreas and spleen. It is indicated for right upper quadrant or epigastric pain, altered liver function, suspected cholelithiasis, jaundice, and screening and follow-up of steatosis and known liver lesions.

This page organizes the protocol in clear language and does not replace the original guidelines (ACR-AIUM-SPR-SRU, AIUM, CBR), supervised training or clinical correlation.

Preparation and technique

Fasting improves gallbladder distension and reduces gas. Clinical urgency takes priority over preparation.

• Fasting of 6 to 8 hours to distend the gallbladder and reduce bowel gas
• Curved transducer of 2 to 5 MHz; abdominal preset with harmonic and compounding
• Windows: subcostal, intercostal and epigastric; deep inspiration to lower the liver
• Left lateral decubitus helps the pancreas and tail; right lateral decubitus helps the spleen
• Document each organ in two planes and measure what is relevant

Liver

Assess size, contours, echotexture and the hepatic and portal veins. The normal liver has echogenicity similar to or slightly higher than the renal cortex.

• Right lobe at the midclavicular line usually up to about 15 to 16 cm
• Homogeneous echotexture, regular contours, no focal lesions
• Patent portal vein, with hepatopetal flow on Doppler when assessed
• Steatosis: hyperechoic liver with posterior attenuation and loss of definition of vessel walls
• Focal lesions (cyst, hemangioma, nodule) described with size, location and features

Gallbladder and bile ducts

• Distended gallbladder, thin wall (up to about 3 mm), anechoic content
• Stones: mobile echogenic images with posterior acoustic shadowing
• Cholecystitis: thickened wall, pericholecystic fluid, sonographic Murphy sign
• Common bile duct usually up to 6 to 7 mm, with physiological increase after cholecystectomy and with age
• Dilation of intra- or extrahepatic bile ducts suggests obstruction to be clarified

Pancreas and spleen

• Pancreas: head, body and tail using the stomach and spleen as a window; thin pancreatic duct
• Homogeneous pancreatic echotexture, isoechoic or slightly hyperechoic relative to the liver
• Bowel gas is the main limitation of the pancreas — note it in the report when it occurs
• Spleen: long axis usually up to about 12 cm, homogeneous echotexture
• Splenomegaly and focal splenic lesions described with measurement

Normal report template

• Liver of normal dimensions, regular contours and homogeneous echotexture, without focal lesions
• Patent portal vein; non-dilated intra- and extrahepatic bile ducts
• Gallbladder with thin walls, without stones or thickening
• Pancreas of preserved echotexture, without ductal dilation (assessment limited by gas when applicable)
• Spleen of normal dimensions and echotexture

Limitations and pitfalls

• Bowel gas limiting the pancreas: report honestly and suggest a new window
• Gallbladder contracted by inadequate fasting, hampering wall and content assessment
• Biliary sludge mistaken for a stone: look for mobility and shadowing
• Slightly enlarged common bile duct in the context of cholecystectomy or age: interpret in context
• Steatosis masking focal lesions through attenuation: correlate and consider a complementary method

Do not overdiagnose

Describe well what is seen, avoid definitive labels on doubtful images, and recommend further workup (return fasting, new plane, CT/MRI) when the doubt is clinically relevant. The conclusion should be proportional to the finding and preserve clinical correlation.

Sources

Educational content; it does not replace original guidelines, medical evaluation or supervised training. Main references:

• ACR-AIUM-SPR-SRU. Practice Parameter for the Performance of an Ultrasound Examination of the Abdomen and/or Retroperitoneum.
• AIUM. Practice Parameter for the Performance of an Ultrasound Examination of the Abdomen and/or Retroperitoneum.
• Brazilian College of Radiology (CBR). Standardization and technical guidelines for ultrasound.
• Rumack CM, Levine D. Diagnostic Ultrasound (upper abdomen anatomy and technique).
• Radiopaedia. Liver, gallbladder and pancreas ultrasound (didactic support, not copied).

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