INDIANAPOLIS—A standardized MRI is important for the diagnosis and follow-up of patients with multiple sclerosis (MS). However, acquisition and interpretation of MRI scans may be complicated due to differences in pulse sequence (eg, FLAIR vs PD/T2), the use of contiguous and thinner (eg, 3 mm vs 5 mm) slices, as well as different patient positioning. Therefore, the Consortium of Multiple Sclerosis Centers (CMSC) convened a task force to develop and periodically revise indications and guidelines for a standardized MRI protocol in the diagnosis and follow-up of patients with MS. The panel’s most recent recommendations were presented at the 2015 CMSC Annual Meeting and will be published in an upcoming issue of American Journal of Neuroradiology.
Lead author Anthony Traboulsee, MD, Associate Professor at the University of British Columbia in Vancouver, and colleagues reported that a standardized brain MRI protocol with gadolinium is recommended for the diagnosis of MS. A spinal cord MRI is additionally recommended if the brain MRI is nondiagnostic or if the presenting symptoms are at the level of the spinal cord. A follow-up brain MRI with gadolinium is recommended to demonstrate dissemination in time and ongoing clinically silent disease activity while on treatment, to evaluate unexpected clinical worsening, to re-assess the original diagnosis, and as a new baseline prior to starting or modifying therapy. A routine brain MRI should be considered every six months to two years for all patients with relapsing MS. The standardized brain MRI protocol includes 3D T1-weighted, 3D T2-FLAIR (fluid-attenuated inversion recovery), 3D T2-weighted, post single-dose gadolinium-enhanced T1-weighted, and a diffusion-weighted sequence.
According to the 2015 Revised CMSC MRI Protocol, a simplified progressive multifocal leukoencephalopathy (PML) surveillance protocol includes FLAIR and diffusion-weighted imaging sequences only.
The spinal cord MRI protocol includes sagittal T1-weighted and proton density, short-time inversion recovery (STIR) or phase-sensitive inversion recovery (PSIR), axial T2- or T2*-weighted through suspicious lesions, and, in some cases, post-contrast gadolinium-enhanced T1-weighted imaging.
The task force’s revised guideline specifies that the clinical question being addressed should be provided in the requisition for the MRI. The radiology report should be descriptive with results referenced to previous studies. MRI studies should be permanently retained and available.
The 2015 revision incorporates new information and practice recommendations, and modification as modern imaging techniques (eg, 3D) have become more robust and available.
Key changes to the MRI protocol since the last revision in 2006 include an emphasis on 3D sequences for brain MRI, a PML-specific monitoring protocol, and an optional orbit MRI protocol for severe optic neuritis.
Key changes to the clinical guidelines since the 2006 revision include more specific guidance on timing of brain MRI for patients on disease-modifying therapy, timing of brain MRI for PML surveillance, updated evidence on the value of MRI changes in determining treatment effectiveness, and inclusion of radiologically isolated syndrome.