Diagnostics

• Most gallstones are asymptomatic.

• Biliary colic: constant, dull RUQ pain lasting < 6 hours

  • Especially postprandial: vagal stimulation (e.g., cholecystokinin release following a fatty meal) → gallbladder contraction → attempts to force the stone into the cystic duct

  • May radiate to the epigastrium, right shoulder, and back (referred pain)

• Nausea, vomiting, early satiety

• Bloating, dyspepsia

Only a minority of patients with gallstones are symptomatic!

• Asymptomatic cholelithiasis : No diagnostic workup is required.

• Suspected symptomatic cholelithiasis

  • Obtain imaging for cholelithiasis: biliary point-of-care ultrasound (POCUS) or transabdominal RUQ ultrasound

  • Rule out complications of cholelithiasis (e.g., acute cholecystitis or choledocholithiasis).

Laboratory studies are typically normal in uncomplicated cholelithiasis but should be ordered to rule out other acute biliary conditions and/or other causes of acute abdominal pain.

• CBC: usually normal

• LFTs: usually normal

• Amylase, lipase: usually normal

Laboratory studies (e.g., WBC count, LFTs, lipase, amylase) are usually normal in uncomplicated cholelithiasis.

If appropriately trained, consider performing a biliary POCUS.

• Indication: best initial test in suspected symptomatic cholelithiasis [6][7]

• Characteristic findings

  • Cholelithiasis

    • Intraluminal highly echogenic foci

    • Strong posterior acoustic shadowing

  • Biliary sludge

    • Low-level echogenic material in the dependent portion of the GB

    • No posterior acoustic shadowing

    • Slow movement with the changing of patient posture

Additional imaging may be required if complications of cholelithiasis (e.g., acute cholecystitis, acute cholangitis, choledocholithiasis, biliary pancreatitis) cannot be ruled out, or to evaluate for other causes of abdominal pain.

MRI abdomen without and with IV contrast with MRCP

• Indications

  • Preferred second-line test if ultrasound findings are inconclusive

  • Suspected choledocholithiasis (see ''Diagnostics'' in choledocholithiasis for further details)

  • MRI without contrast is preferred in pregnant patients.

• Supportive findings: well-defined hypointense (on T2) filling defect(s) within the gallbladder lumen

• Indications

  • Inconclusive ultrasound findings; MRI is not available

  • Suspected complications and/or differential diagnoses

  • Preoperative planning after confirming the diagnosis

• Supportive findings (of radiopaque stones): well-defined hyperdense structure(s) within the gallbladder lumen

• Disadvantages

  • Only radiopaque stones are detectable (15–20% of stones are radiopaque).

  • Cannot detect the more common radiolucent pure cholesterol stones

• Indication: usually not indicated in the evaluation of cholelithiasis, but may be performed as part of the workup of acute abdominal pain

• Findings: gallstones with an outer radiopaque rim and radiolucent center [16]

• Disadvantages: similar to those of CT scan

X-ray and CT scan are rarely diagnostic in cholelithiasis because only 15–20% of stones are radiopaque. Pure cholesterol stones are radiolucent.

• Abdominal

  • Choledocholithiasis

  • Acute cholecystitis

  • Acute cholangitis

  • Acute hepatic capsule swelling (e.g., acute hepatitis, perihepatitis, congestive hepatopathy)

  • Gastroesophageal reflux, gastritis, gastrointestinal ulcers

  • Early appendicitis

  • Acute pancreatitis

  • Right-sided diverticulitis

  • Sphincter of Oddi dysfunction

• Extra-abdominal

  • Nephrolithiasis

  • Acute coronary syndrome

• Cholangiocarcinoma (see biliary cancer)

• Gallbladder polyp

  • Definition: benign tumor of the gallbladder wall with low metastatic potential

  • Epidemiology

    • 5% of polyps are adenomas, which are premalignant

    • Up to 50% of polyps > 1 cm are carcinomas

    
    

    • Diagnosis: Ultrasound (transabdominal or endoscopic)

    • Parietal echogenic tumor, easily mistaken for a gallstone

    • No change in position of pathology during movement or acoustic shadow (in contrast to a gallstone)