From the Guidelines
The best initial imaging for right upper quadrant (RUQ) pain is an abdominal ultrasound, as it provides excellent visualization of the gallbladder, liver, and biliary system, which are common sources of RUQ pain, and can detect gallstones, cholecystitis, biliary obstruction, and liver abnormalities without radiation exposure 1.
Key Points to Consider
- Ultrasound is the first choice of investigation for biliary symptoms or right upper quadrant abdominal pain, with a reported accuracy of 96% for detection of gallstones 1.
- Although cholescintigraphy has a higher sensitivity and specificity for the evaluation of acute cholecystitis, US remains the initial test of choice due to its shorter study time, morphologic evaluation, and ability to confirm the presence or absence of gallstones 1.
- If ultrasound results are inconclusive or additional information is needed, a contrast-enhanced CT scan of the abdomen would be the next appropriate step, as it offers more comprehensive evaluation of all abdominal organs and can detect inflammatory conditions, masses, and vascular issues.
- For suspected biliary disease that remains unclear after ultrasound, magnetic resonance cholangiopancreatography (MRCP) provides detailed imaging of the bile and pancreatic ducts.
- In cases of acute severe pain where perforation or acute inflammation is suspected, CT is often preferred as the initial test due to its speed and ability to detect complications.
Patient Factors to Consider
- Pregnancy status, where ultrasound would be strongly preferred due to lack of radiation.
- The patient's clinical presentation and suspected diagnosis, which should guide the choice between imaging modalities.
From the Research
Imaging Modalities for Right Upper Quadrant Pain
- Ultrasound is the imaging modality of choice for the initial evaluation of patients who present with right upper quadrant pain 2, 3, 4
- CT is often used as part of a broader evaluation of patient's abdominal pain if nongallbladder pathologies are also suspected 2, 3
- MRI/MRCP is typically reserved for problem-solving and evaluating patients who present with cholestatic presentation 2
- Radionuclide imaging, computed tomography (CT), and MR imaging also play important roles in evaluating patients with right upper quadrant pain 3
- MR cholangiopancreatography achieves high accuracy in diagnosis of choledocholithiasis and allows for noninvasive imaging when ultrasonography and CT are indeterminate 3
Clinical Approach to Imaging
- For patients presenting with a positive Murphy sign, sonography and biliary scintigraphy are the most useful initial imaging techniques 4
- In patients with fever and a negative Murphy sign, a combination of sonography and contrast-enhanced CT can establish the diagnosis in most cases 4
- In patients without fever or a positive Murphy sign, CT and MR are appropriate first-line imaging techniques 4
Note on Irrelevant Study
- One study 5 is not relevant to the topic of imaging for right upper quadrant pain, as it discusses the generation and characterization of temperature-sensitive mutants of the Eastern equine encephalomyelitis virus.