|author2=
}}
==Procedure==
*Take an initial anteroposterior image including the presumed locations of the gallbladder and common bile duct.
*Infuse iodinated contrast, usually amounting to approximately 5-10g 5g of iodine (or about 10 to 30 20 ml of concentration 350mg240mg/ml, but can possibly be multiple times more), and note the following:
:*Location of the tip of the drain in relation to the gallbladder
:*Flow into the duodenum, or most distal part reached.