What does enhancing and non-enhancing mean in regards to a CT scan?

Can anyone tell me what those two terms mean, that is "enhancing" and "non-enahcning" mean in regards to the results of a CT scan where a "non-enahncing" mass (1.2 cm) was found in the head of my wife's pancreas?

[555boston]

Usually a dye containg iodine is injected when a CT scan is obtained. Enhancing lesions mean that the radiologist sees a a lot of dye in the area of concern. This means either there is a lot of blood flow to the area or there are lot of leaky veins in the area which allow the dye to come out of the blood stream into the tissue. Usually cancers have a lot of leaky aretries and veins in them, and alos have a lot of blood flow,  so they are "enhancing".