What is the recommended evaluation and management for a patient presenting with right upper quadrant pain, including red‑flag assessment, laboratory work‑up, imaging, and treatment options?

Right Upper Quadrant Pain: Evaluation and Management

Initial Imaging

Right upper quadrant ultrasound is the mandatory first-line imaging study for all patients presenting with RUQ pain, regardless of clinical suspicion. 1, 2, 3

• Ultrasound achieves 81% sensitivity and 83% specificity for acute cholecystitis and 96% accuracy for detecting gallstones 1, 3
• The American College of Radiology rates RUQ ultrasound as 9/9 (usually appropriate) for initial evaluation 1
• Do not skip ultrasound and proceed directly to CT unless the patient is hemodynamically unstable 1

Critical Red-Flag Assessment

Laboratory Work-Up (Obtain Before Imaging)

• Beta-hCG (pregnancy test) in all women of reproductive age before any imaging—this is non-negotiable 1
• Complete metabolic panel including liver function tests (AST, ALT, alkaline phosphatase, GGT, total/direct bilirubin) 1, 2
• Complete blood count to assess for leukocytosis suggesting infection 2

Clinical Red Flags to Identify

• Fever with jaundice and RUQ pain suggests acute cholangitis requiring urgent ERCP 2
• Peritoneal signs or hemodynamic instability indicate possible perforation or gangrenous cholecystitis 2
• Pain specifically triggered by bowel movements suggests colonic pathology (hepatic flexure) rather than primary biliary disease 1

Algorithmic Approach Based on Ultrasound Findings

If Ultrasound Shows Gallstones + Cholecystitis Features

• Two or more supportive features (wall thickening >3mm, pericholecystic fluid, sonographic Murphy sign) confirm cholecystitis 4
• Proceed directly to surgical consultation for cholecystectomy 5
• If fever and elevated WBC with equivocal ultrasound, order HIDA scan (96% sensitivity, 90% specificity for acute cholecystitis) 1

If Ultrasound Shows Dilated Common Bile Duct or Elevated LFTs

Order MRCP as the next imaging study—not HIDA scan, not repeat CT 2

• MRCP achieves 85-100% sensitivity and 90% specificity for choledocholithiasis 2, 3
• MRCP identifies the level and cause of biliary obstruction with 91-100% accuracy 2, 3
• Elevated LFTs indicate biliary obstruction requiring anatomic visualization of bile ducts, which MRCP provides but HIDA scan does not 2
• MRCP visualizes the common bile duct and cystic duct superior to ultrasound 2

If Ultrasound is Negative or Equivocal

Proceed to CT abdomen/pelvis with IV contrast to evaluate for non-biliary causes 1

• CT has >95% sensitivity for detecting colonic pathology and alternative diagnoses beyond the gallbladder 1
• CT identifies acute nongallbladder abnormalities missed by ultrasound in 32% of cases 4
• Reserve CT for critically ill patients with suspected complications (emphysematous cholecystitis, perforation, abscess) 2

If Both Ultrasound and CT are Negative with Persistent Pain

Order MRCP with IV gadolinium contrast as the definitive next study 2

• MRCP provides superior visualization of the biliary tree compared to repeat ultrasound or CT 2
• Do not repeat ultrasound or CT after initial negative work-up—these add no diagnostic value 2
• Consider empiric trial of proton-pump inhibitor (omeprazole 20-40 mg daily for 4-8 weeks) for possible gastroesophageal or peptic ulcer disease 2
• If MRCP and PPI trial both fail, proceed to upper endoscopy 2

Special Clinical Scenarios

Jaundice with RUQ Pain

• Ultrasound first to detect biliary dilatation (71-97% specificity for mechanical obstruction) 2, 3
• If biliary dilatation present, proceed directly to MRCP 2, 3
• ERCP is therapeutic, not diagnostic—only perform after non-invasive imaging confirms obstruction requiring intervention 2

Heterogeneous Liver on Ultrasound

• Order MRI abdomen with MRCP and IV gadolinium contrast for comprehensive hepatobiliary evaluation 2
• Evaluate for chronic liver disease (cirrhosis, fatty liver, metabolic syndrome) 2
• Do not dismiss heterogeneous liver as "normal variant" in the context of RUQ pain 2

Acalculous Cholecystitis Suspected

• HIDA scan is the imaging examination of choice 2
• This scenario typically occurs in critically ill, ICU, or post-operative patients 2

Critical Pitfalls to Avoid

• Pain triggered by bowel movements suggests colonic causes, not primary hepatobiliary disease (which presents with postprandial pain) 1
• Sonographic Murphy sign has low specificity if patient received pain medication prior to imaging 2
• Many gallstones are radiolucent (up to 80% noncalcified), limiting CT utility for stone detection 2
• Do not order HIDA scan as primary test for elevated LFTs and RUQ pain unless acute cholecystitis is the primary concern 2
• Iodinated contrast allergy does not require precautions for gadolinium-based MRI contrast 2

Treatment Considerations

• Uncomplicated acute cholecystitis: urgent surgical cholecystectomy 5
• Complicated cholecystitis (perforation, gangrene): supportive measures initially, elective cholecystectomy later 5
• Choledocholithiasis with obstruction: ERCP for stone extraction 2
• Acute cholangitis: urgent ERCP with biliary decompression 2