Evaluating Patients with Right Upper Quadrant Pain.

Many disorders of the liver, gallbladder, and biliary tree may cause right upper quadrant pain and clinical diagnosis may be challenging. Imaging plays a key role in establishing a prompt diagnosis and guiding appropriate management. Although ultrasonography is the initial imaging modality of choice for most hepatobiliary disorders, radionuclide imaging, computed tomography (CT), and MR imaging also play important roles. Acute cholecystitis may be associated with many complications that have characteristic imaging features. MR cholangiopancreatography achieves high accuracy in diagnosis of choledocholithiasis and allows for noninvasive imaging when ultrasonography and CT are indeterminate.