It’s my understanding that lesions will show up even without contrast. The contrast is used to show if they are active or not. I had my first MRI done without contrast, and then they called me back for a second one once they’d viewed it and found a lesion. Other MRI facilities will perform the MRI without contrast, have the radiologist view it right away, and determine right then if they need to add contrast and do additional sequences. Since you had problems with the CT contrast, it’s probably a really good thing that you’re not getting the MRI contrast until they determine if it is really necessary.
I hope all goes well for you tomorrow,