| MRCP |
| Advantages |
| Noninvasive |
| Intravenous contrast usually given but not required |
| Established technique, widely available |
| Disadvantages |
| Time consuming |
| Contraindications such as cardiac pacemaker/defibrillator, intracranial metal clips |
| False-positive studies (eg, intraductal artifacts such as air or blood, image reconstruction artifacts, motion artifacts) |
| False-negative studies (eg, stones in dilated CBD or stones <5 mm in the distal duct may not be visualized well) |
| EUS |
| Advantages |
| Very high resolution (0.1 mm) compared with MRCP (1.5 mm) |
| Dynamic imaging allowing manipulation and magnification of image for better visualization |
| ERCP can potentially be performed in the same setting for stone removal |
| Can be performed at the bedside in critically ill patients |
| Disadvantages |
| More invasive than MRCP |
| Need for sedation |
| Risks associated with sedation (eg, cardiopulmonary compromise) and endoscopy (eg, bleeding and perforation) |
| Limited availability of equipment and trained endosonographers |
| Not possible or limited role in altered anatomy (eg, pyloric stenosis, Roux-en-Y bypass) |
