Brain MRI without contrast agent is just as effective as the contrast-enhanced approach for monitoring disease progression in patients with multiple sclerosis, according to a new study. The findings support the possibility that contrast enhancement can be omitted from routine follow-up scans.

MRI with the administration of gadolinium-based contrast material is widely considered obligatory for follow-up scans of patients with MS. Gadolinium, a heavy metal, enhances the images and helps provide important diagnostic information, but it leads to both prolonged scan times and increased costs. There is also evidence that some of the metal remains in the body after contrast administration, although the long-term clinical effect of these deposits is unclear.

Advances in noncontrast MRI image acquisition and post-processing technology, along with the increasing availability of powerful 3T MRI machines, have raised the possibility that nonenhanced scans could have a role in MS follow-up imaging. To learn more, researchers at the Technische Universität München in Munich, Germany, used MRI to assess new or enlarged lesions in 359 patients with MS. 

Of 507 follow-up scans, 264 showed interval progression, defined by as at least one new or unequivocally enlarged lesion on follow-up MRI scans. There were a total of 1,992 new or enlarged lesions. With 3T MRI, the assessment of interval progression did not differ significantly between the contrast-enhanced and nonenhanced images.

The researchers credited an image subtraction pipeline developed and researched at his facility for the powerful sensitivity of the noncontrast MRI in detecting newly occurring lesions. The approach combines 3-D MRI and subtraction techniques, which cancel out unchanged areas in the follow-up image, substantially improving visualization of new or enlarging white matter lesions. This combination of 3-D sequences and subtraction techniques is key to improving sensitivity for detecting newly occurred lesions.

The study was published in the journal Radiology.