Imaging in Multiple Sclerosis – Whats has changed so far? 2017 guidelines and more
MRI plays a vital role in monitoring disease progression and treatment efficacy in Multiple Sclerosis.Before discussion on guidelines, it is beneficial to review the imaging protocol and standard sequences used. Compulsory sequences being - axial PD or T2-weighted/T2- FLAIR spin echo or turbo spin echo, sagittal 2D or 3D T2-FLAIR and axial 2D or 3D post-contrast T1-weighted spin echo or turbo spin echo sequences. T2 axial images are superior for posterior fossa lesions.According to MAGNIMS criteria 2D or high-resolution 3D T1-weighted, 2D or 3D dual inversion recovery, and axial DWI can be additionally added to imaging.
A single dose of gadolinium-based contrast is administered (0.1 mmol/kg), and a minimum of a 5-min delay until T1 sequence acquisition is recommended.
Since the 2010 Mc Donald criteria Consortium of Multiple Sclerosis Centers (CMSC) 2017 declared need for revision due to -
- New data on the relationship of MS and neuromyelitis optica spectrum disorders ;
- Recognition that MS is frequently misdiagnosed;
- New data showing utility of CSF in diagnosis and the need to emphasize its value;
- Need for better performance of the criteria in special populations.
- Identification of subsets of patients with a high likelihood of MS but in whom the 2010 criteria are not diagnostic; and
- Recently revised criteria from MAGNIMS So what is ''in'' and what is ''out''?
- Imaging spinal cord lesions which aids in diagnosis as well as exclusion of other pathology.
- Cortical lesions also to be included.
- MS lesions are oriented around a central vein and these findings are referred to as central vein sign (CVS)- SWI and FLAIR useful
- Regional white matter atrophy- the involvement of white matter tracts and decreased volume of the corpus callosum at baseline, specially thalamic atrophy has been found to be predictive for developing MS.
- The desired endpoint 'no evidence of disease activity' (NEDA) is based on the absence of new activity on MRI, as well as on absence of relapses and disability, and has been utilized to assess positive treatment response for patients with RRMS after 2 years as mentioned in the article.
- However, the most controversial change (Reference: MedPage Today, October 26, 2017) was allowing use the presence of OCBs in CSF to make the diagnosis of MS in a patient with the typical clinically isolated syndrome (CIS) who has clinical or MRI evidence of dissemination in space.
- Both symptomatic and asymptomatic MRI lesions can be considered in determining dissemination in space and time
For reference log on to :
MS- Multiple Sclerosis
FLAIR- fluid-attenuated inversion recovery
DWI- Diffusion-weighted imaging
MAGNIMS- magnetic resonance imaging in multiple sclerosis
RRMS- Relapsing-Remitting Multiple Sclerosis
OCBs- Oligoclonal bands
Source: Kaunzner UW, Gauthier SA. MRI in the assessment and monitoring of multiple sclerosis: an update on best practice. Therapeutic Advances in Neurological Disorders. 2017;10(6):247-261. doi:10.1177/1756285617708911.
Dr. Niharika Prasad,
The author is MD (Radiodiagnosis) and is Senior Resident, Dept of Radiology in All India Institute of Medical Sciences, AIIMS Patna. She is a member Editorial Board, Radiology at Specialty Medical Dialogues.