Final answer:
Ductography is the technique used to assess and evaluate nipple discharge by checking for defects or wall irregularities.
Step-by-step explanation:
The technique used to assess and evaluate nipple discharge by checking for defects or wall irregularities is called ductography. Ductography is an imaging technique that involves injecting a contrast dye into the milk ducts of the breast and then taking X-ray images to visualize the ducts and identify any abnormalities. It is commonly used to investigate nipple discharge and determine the cause.