CT uses radiation to make these pictures and MRI uses magnetic field.... which one is better ? definitely MRI without "gandolinium" contrast-- pictures are sharp and tumors are well defined and it's SAFE. All contrasts CT or MRI are hard on your kidneys...but your doctor will tell you that " benefits will outweigh the risk". Google gandolinium and read about pros and cons of using it and same for CT contrast.
Penny, if you go to the top of the page, on the right you will see an area that says "search MedHelp" type in CT scan, then MRI you should get the answers to your questions.
With the CT scan you're having tomorrow, you lie on a table and it slides you into a machine for about a minute, and the machine takes pictures which the radiologist reads, and sends a report to your doctor. It's no big deal.
The drink you're having at home, might be barium, read the bottle. It doesn't taste bad, but refrigerate it till it's time to drink it. I wasn't allowed to eat for a few hours before the CT.
You'll get the contrast dye when you're ready to have the CT.
If you still need answers, you should google the tests, you'll see pictures of the machines, and what the tests are like.
Good luck tomorrow.
Jane