Contrast is the gold standard, though it can be done without. However, not using it requires coordination so the radiologist knows they are looking for an AN. Without contrast also can miss certain types (small, certain locations). Lastly, I think if one is detected without, I think they would repeat with contrast to confirm, and to treat it, I don't know how they would do it without the contrast because they need the detail--they also use a more powerful machine to clearly identify the border of the tumor, but that is down the road. The needle is very small, and depending on the imaging place, they can do automatic injection of the contrast--you are in for a precontrast, then they inject the contrast and reshoot without coming out of the MRI. In my opinion, the MRI is the most stressing aspect due to claustrophobia. I think if you have a good doctor they are very flexible. One thing to keep in mind, if you are diagnosed with an AN, your doctor will want all those images, from the beginning through current treatment, in order to measure size and track growth.
