What is the next step in evaluating a patient with right upper quadrant pain and normal liver function tests?

Right Upper Quadrant Pain with Normal Liver Function Tests

Obtain right upper quadrant ultrasound immediately as the first-line imaging study to evaluate for gallbladder pathology, hepatic abnormalities, and alternative diagnoses. 1, 2, 3

Why Ultrasound First

Normal liver function tests do not exclude significant biliary or hepatic pathology—they simply indicate the absence of cholestasis or hepatocellular injury at the time of testing. The diagnostic approach differs fundamentally from patients with elevated LFTs:

• The American College of Radiology rates RUQ ultrasound as 9/9 (usually appropriate) for RUQ pain evaluation, regardless of LFT status. 2, 3
• Ultrasound detects gallstones with 96% accuracy, identifies gallbladder wall thickening, pericholecystic fluid, and assesses both intrahepatic and extrahepatic bile ducts. 1
• Ultrasound has 81% sensitivity and 83% specificity for acute cholecystitis, which commonly presents with normal LFTs in early or uncomplicated disease. 2
• Over one-third of patients with acute RUQ pain do not have acute cholecystitis, making comprehensive ultrasound evaluation essential to identify alternative diagnoses including hepatic masses, renal pathology, pancreatic disease, and even thoracic processes. 4, 5

Algorithmic Approach After Initial Ultrasound

If Ultrasound Shows Gallbladder Pathology (stones, wall thickening):

• Consider HIDA scan if acute cholecystitis is suspected but ultrasound findings are equivocal, particularly with fever and elevated WBC count. 1
• HIDA scan has 96% sensitivity and 90% specificity for acute cholecystitis, superior to ultrasound in equivocal cases. 2
• HIDA scan is the imaging examination of choice for suspected acalculous cholecystitis. 1

If Ultrasound is Negative or Non-Diagnostic:

• Proceed to CT abdomen/pelvis with IV contrast, which has greater than 95% sensitivity for detecting colonic pathology and identifies complications beyond the gallbladder. 2
• CT is valuable for confirming complications of cholecystitis (perforation, abscess) and evaluating non-biliary causes including pancreatic inflammation, colonic pathology, renal obstruction, and adrenal hemorrhage. 6, 4
• Consider MRCP only if biliary tree pathology remains suspected despite normal ultrasound, though this is less likely with normal LFTs. 1

If Ultrasound Shows a Solid Mass:

• Do not assume benignity—proceed to contrast-enhanced MRI or CT to evaluate for malignancy, abscess, or other pathology requiring intervention. 3
• MRI abdomen with IV contrast is superior to CT for characterizing hepatic masses. 3

Critical Clinical Pitfalls to Avoid

• Never skip ultrasound and proceed directly to CT or advanced imaging unless the patient is hemodynamically unstable—ultrasound is more appropriate for initial evaluation and avoids unnecessary radiation exposure. 2, 3
• Normal LFTs do not exclude biliary colic, early cholecystitis, or gallbladder dyskinesia, which may present with intermittent RUQ pain and entirely normal laboratory values. 1
• The sonographic Murphy sign has relatively low specificity for acute cholecystitis and is unreliable if the patient received pain medication prior to imaging. 1
• Pain timing matters: Pain specifically triggered by bowel movements suggests colonic or mechanical causes rather than primary hepatobiliary disease, which typically presents with postprandial pain. 2
• Broaden your differential after negative hepatobiliary workup—referred pain from thoracic processes (pneumonia, empyema) or spinal pathology (discitis, paraspinal abscess) can present as RUQ pain with normal LFTs. 7, 5
• Ultrasound has limitations in visualizing the hepatic dome, areas beneath ribs, and distal extrahepatic ducts when not dilated—if clinical suspicion remains high despite negative ultrasound, proceed to CT or MRCP based on the suspected pathology. 6