In the past 3½ decades we have witnessed the introduction of multiple new imaging techniques: endoscopic retrograde cholangiopancreatography (ERCP), percutaneous transhepatic cholangiography, transcutaneous ultrasonography, computed tomography (CT), and, most recently, endoscopic ultrasonography and magnetic resonance cholangiopancreatography (MRCP). All techniques have their proponents, and each has inherent advantages and limitations. Currently, there seems to be no universally accepted consensus on the imaging procedure-of-choice in patients with presumed or suspected mechanical biliary obstruction, as either a diagnostic or a staging procedure.
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