The breast is cleaned to avoid infection and the duct producing the discharge is identified. A very tiny catheter (not a needle) is placed into the duct and a small amount of contrast is injected into the duct. This outlines any abnormalities inside the mammographic duct. Mammographic images are then taken. The procedure usually takes from one-half hour to one hour and is usually completely painless. On the day of the procedure the patient should wear a comfortable two-piece outfit. She can drive herself home following the procedure and may resume all normal activities.