brain imaging in ms - 3 steps to optimize your mri protocol
TRANSCRIPT
THE ROLE OF MRI FOR PEOPLE WITHM S I S G A I N I N G I M P O RTA N C E
Poser criteria
McDonald criteria 2001
McDonald criteria 2005
McDonald criteria 2010
time
importance
Brain imaging in MS 3 steps to optimize your MRI protocol
Brain imaging in MS3 steps to optimize your MRI protocol
2 31Sequence improvement Frequency optimization Communication
3 steps to optimize your MRI protocol, based on the most recent MRI guidelines of the CMSC1 and the MAGNIMS2 group and our personal experience in the field of MRI post-processing.
1 Douglas L Arnold et al. 2015. Evolving role of MRI in optimizing the treatment of multiple sclerosis: Canadian Consensus recommendations. Multiple Sclerosis Journal Experimental, Translational and Clinical.2 Mike P Wattjes et al. 2015. MAGNIMS consensus guidelines on the use of MRI in multiple sclerosis—establishing disease prognosis and monitoring patients. Nature Reviews Neurology.
1 Sequence improvement: Sequence choice
Sequence DescriptionEssential 3D (contrast enhanced) T1 – Weighted
Sagittal 3DT2 - FLAIR(1.0 – 1,5 x 1 x 1 mm)
Optional 3D (contrast enhanced) T1 – Weighted2D or 3D T2 – WeightedAxial 2D DWI*2D or 3D DIR*
(1.0 – 1,5 x 1 x 1 mm)(1.0 – 3 x 1 x 1 mm)
*DWI: diffusion weighted imaging, DIR: double inversion recovery
MRI scan time can be kept below 20-30 min per patient while still obtaining high quality data.
Minimum required sequences for MS follow up: • 3D T1-weighted sequence with or without contrast enhancement • 3D T2-FLAIR sequence.
Depending on the needs of your individual patient, some optional sequences can be included such as: (un)enhanced 3D T1-weighted, 2D or 3D T2-weighted, 2D axial diffusion-weighted images and 2D or 3D double inversion recovery sequences.
1 Sequence improvement: Scanner parameter description
Scanner parameter descriptionCoverage Whole brain, including skull
Position Consistent axial orientation (e.g. along subcallosal line)
Field Strength 1,5 Tesla or 3.0 Tesla
Slice Thickness 1 – 1.5 mm for 3D, 1.5 – 3mm for 2D, no gap
In plane resolution 1 x 1 mm
Correct patient position and complete brain coverage is essential. An acceptable SNR and spatial resolution should be obtained by using a field strength of 1.5T or 3T.
Sequence parameters, scanner type and software can have a significant impact on brain tissue and lesion visualization. To conclude: consistency in time of all aforementioned factors is crucial.
Frequency optimization2When to scanIf no baseline MRI scan is available
Annual routine follow-up to detect subclinical activity and/or PML surveillance*
Before starting or switching treatment
6 months after starting or switching treatment to establish a new baseline
Sudden clinical worsening or re-evaluation of diagnosis
After pregnancy to establish a new baseline *PML: progressive multifocal leukoencephalopathy
Regular MRI follow-up is needed to keep track of potential subclinical deterioration. Annual MRI evaluation is generally sufficient, but frequency can be adjusted based on the patient’s status.
A usable baseline is crucial to correctly interpret disease progression. Reassessment is therefore required after a pregnancy or change in treatment.
1 Communication3
What to request? What to report?Clinical purpose (regular follow-up or specific reason)
MRI sequences, scanner parameters and used contract agent
Clinical history(onset, symptoms and relapses)
Number of contrast-enhanced lesions
Current DMT* Overall lesion load
Recently administered corticosteroids Brain atrophy
Timing and location of previous scans Incidental, atypical or MS-unrelated findings*DMT: disease modifying treatment
Effective communication between neurologist and radiologist is crucial. MRI requests should contain all the necessary information so the correct sequences can be acquired to answer the addressed clinical question.
