Hi: Sorry for jumping in, but in my case "with contrast" always meant that they used an iv to administer the dye.
I've had scans done for mine spine, abdomen, gall bladder, etc, and when they were looking for lesions or at a mass of some kind, discs or canal probs they would do one [U]with[/U] and one [U]without[/U] contrast to make a comparison. I guess it depends on what the Dr *wants* and is *looking* for. I've also had scans of my spine where they didn't use contrast, so I don't really know what it depends on. I just had a cervical spine scan, because of constant pain and loss of movement, and they didn't order the contrast.
Good luck I hope it goes really well.