Just had the MRI of the brain today to help rule out neurosarcoidosis. Prof. Ayliffe had requested with and without contrast as long as I wasn't allergic to the dye.
I had to argue with the hospital because they said it was radilogical protocol NOT to use contrast. When I showed up for the MRI they said, "we will be doing the MRI with contrast because you have sarcoidosis"
Anyway I wanted to know what the difference was so I looked it up. See below. I suspect "radiological protocol" is actually to wait and see if MRI without contrast is normal or not.
MRI with contrast is a more sensitive test than MRI without contrast, when looking for
certain types of abnormalities, for instance brain tumors while obvious on regular MRI are very
easy to see as the contrast (gadolinium ) is taken up by the tumor causing it to "glow'
on the final scan.
Some lesions like active MS plaques are very obvious on a contrast enhanced scan, the may be seen
on a routine scan but the uptake of contrtast indicates that the lesion is active and recent
as opposed to older and inactive.
In most cases abnormalities are seen on a non-contrast scan , but the
visualisation is much better and more information is obtained using contrast.
If the non-enhanced scan is totally normal the need for a contrast image is not so
Edited April 13, 2012 at 9:16 am