Can you tell me what it mean to have a head and orbit ct w/ and w/o?

Head and orbit CT: W/ and w/o means with and without IV contrast. The head ct without contrast is good for looking at any blood in the head and any major abnormalities. Contrast is given to look for any enhancing abnormalities such as masses. The orbit ct covers some of the same area as the head ct but thinner cuts are done to see the fine detail of the bones and soft tissues of the eye sockets.

Contrast: It just means with and without contrast. The contrast can help in detecting tumors or abscesse