With or without contrast? What are the indications for gadolinium-enchanced brain or spine MRI?

MRI contrast increases sensitivity for neoplasms and infectious/inflammatory lesions (abscess, encephalitis, myelitis, etc).   It is also helpful in evaluating a post-operative spine as it helps distinguish disc herniation from postsurgical scarring and fibrosis. While an MRA brain can be done without contrast, a contrasted study can increase the quality of the images. 

Bottom line, most MRI's ordered from the ED, with exception of brain MRIs to evaluate specifically for ischemia, should be done with gadolinium enhancement.  Fortunately, gadolinium contrast is generally well tolerated with few allergic reactions and does not directly degrade renal function.  However, high doses of gadolinium should be used with caution in those with severe renal insufficiency as it can cause a delayed fibrotic process (nephrogenic systemic fibrosis). 


Source

Meritt's Neurology.  12 ed.