Diagnostic Approach to Gallstone Disease

Initial Diagnostic Workup

The American College of Gastroenterology recommends that liver biochemical tests, including ALT, AST, bilirubin, ALP, and GGT, and abdominal ultrasound should be performed as the initial diagnostic investigations for patients suspected of having gallstones 1, 2
Trans-abdominal ultrasound scanning and liver function tests are the recommended first-line investigations for patients with suspected gallstones, with normal results not precluding further investigation if clinical suspicion remains high 1, 3
A complete liver biochemistry panel should include bilirubin, ALT, and AST, among other tests 2, 4
Full blood count and international normalized ratio/prothrombin time should be performed, especially if endoscopic or surgical intervention is being considered 5

Normal liver biochemical tests have a high negative predictive value of 97% for common bile duct stones, but the positive predictive value of any abnormal liver biochemical test result is only 15% 2, 6
Direct visualization of common bile duct stones on abdominal ultrasound is a very strong predictor of choledocholithiasis 2
The American Society of Gastrointestinal Endoscopy and the Society of American Gastrointestinal Endoscopic Surgeons recommend risk stratification for common bile duct stones based on predictors such as visualization of common bile duct stone on ultrasound, common bile duct dilation, and bilirubin level 2, 6, 7

The American Society of Gastrointestinal Endoscopy and the Society of American Gastrointestinal Endoscopic Surgeons recommend the following risk stratification for common bile duct stones:

For patients with moderate risk for choledocholithiasis, additional investigations such as magnetic resonance cholangiopancreatography, endoscopic ultrasound, intraoperative cholangiography, and laparoscopic ultrasound should be considered 2, 3, 7, 8

In patients with suspected gallstone-related pancreatitis, additional blood tests such as serum amylase or lipase, triglyceride level, and calcium level should be performed 8, 9
For patients undergoing biliary sphincterotomy for ductal stones, full blood count and coagulation studies must be performed prior to the procedure 5

The American College of Radiology recommends ultrasound of the abdomen as the first-line imaging modality for suspected gallstones, with reported accuracy of 96% for detection of gallstones, and it has advantages such as being non-invasive, no radiation exposure, relatively inexpensive, portable, and results generally available quickly 10, 11
Ultrasound can identify gallstones, gallbladder wall thickening, pericholecystic fluid, and gallbladder sludge, and can also evaluate intrahepatic and extrahepatic bile ducts for dilation 10

For suspected acute cholecystitis with equivocal US, a CT scan can be considered as subsequent imaging to identify complications and rule out other etiologies, and hepatobiliary iminodiacetic acid (HIDA) scan is considered the gold standard for diagnosing acute cholecystitis 10, 11
In pregnant patients with suspected gallstones, ultrasound or MRI can be considered as the initial diagnostic imaging modality to avoid radiation exposure 11

Ultrasound results may be limited by abdominal tenderness and patient obesity 10, 11