Table 3.
Recommended standardized brain, optic nerve, and spinal MRI protocols for MS diagnosis.
| Brain | Spinal cord | Optic nerve | |
|---|---|---|---|
| Suggested MRI parameters | |||
| Field strength | ≥1.5 T (preferably 3.0 T) | ≥1.5 T (3.0 T has no added value compared with 1.5 T) | ≥1.5 T |
| Slice thickness | For 3D imaging: 1 mm isotropic is preferred but, if over contiguous (through plane and in plane), not >1.5 mm, with 0.75 mm overlap For 2D imaging: ≤3 mm with no gap (except for diffusion-weighted imaging, for which the slice thickness should be ≤ 5 mm with a 10–30% gap) |
Sagittal slices should be ≤ 3 mm with no gap; axial slices should be ≤ 5 mm with no gap | ≤2–3 mm with no gap |
| In-plane resolution | ≤1 mm × 1 mm | ≤1 mm × 1 mm | ≤1 mm × 1 mm |
| Coverage | Whole brain (include as much of cervical cord as possible) | Cervical and thoraco-lumbar spinal cord, to include conus | Optic nerve and optic chiasm |
| Axial scan orientation | Subcallosal plane to prescribe (i.e., for 2D imaging) or reformat (i.e., for 3D imaging) axial oblique slices | Perpendicular to the sagittal axis of the spinal cord | Aligned to the orientation of the optic nerve and optic chiasm |
| MRI sequence | |||
| Recommended | Axial T2-weighted (TSE or FSE) sequencesa | At least two of: sagittal T2-weighted sequences (TSE or FSE), PD-weighted sequences (TSE or FSE), or STIR | |
| Sagittal T2-weighted FLAIR (preferably 3D; fat suppression is optional) | |||
| Axial T2-weighted FLAIR (unnecessary if a sagittal 3D FLAIR with multiplanar reconstruction is obtained; fat suppression is optional) | Sagittal T1-weighted sequences (TSE or FSE) after contrastb | ||
| Axial (or 3D sagittal) T1-weighted sequences after contrastb | |||
| Optional | Diffusion-weighted imaging | Sagittal 3D heavily T1-weighted sequences (PSIR or magnetisation-prepared rapid acquisition of gradient echoesc) only for the cervical segment | Axial and coronal fat-suppressed T2-weighted sequences or STIR of optic nerved |
| DIR or PSIR for detecting cortical or juxtacortical lesions | Axial T2-weighted (TSE or FSE) or gradient-recalled echoe | ||
| High-resolution T1-weighted sequences (isotropic 3D acquisition; for quantitative assessment of brain volume) | Sagittal T1-weighted sequences (TSE or FSE) before contrast | Axial and coronal fat-suppressed T1-weighted sequences post contrast of optic nerved | |
| Axial T1-weighted sequences (TSE or FSE) after contrastb |
Abbreviations: 2D, two-dimensional; 3D, three-dimensional; DIR, double inversion recovery; FLAIR, fluid-attenuated inversion recovery; FSE, fast spin echo; PD, proton density; PSIR, phase-sensitive inversion recovery; TSE, turbo spin echo; STIR, short tau inversion recovery.
A dual echo (proton density-weighted and T2-weighted) sequence can be considered as an alternative to a single echo T2-weighted sequence.
Standard doses of 0.1 mmol/kg bodyweight, macrocyclic gadolinium chelates only, with a minimum delay of 5–10 min.
One of these sequences could replace T2-weighted sequences, proton density-weighted sequences, or short tau inversion recovery.
The acquisition of this sequence can be considered in some clinical situations; 2D or 3D acquisition.
To corroborate, characterize, and confirm lesions detected on sagittal images or to detect lesions in spinal cord segments with high clinical suspicions of involvement.6