Table 2.
MRI sequences useful to predict disability and progression in MS.
| Sequence* | Useful findings in impairment prediction and disease progression | Technical considerations and limitations |
|---|---|---|
| T2, PD, FLAIR | - Initial lesion load and appearance of new lesions in baseline studies - Topography of lesions (i.e., protuberance, midbrain, and spinal cord) |
|
| DIR, 3D T1, MPRAGE/MP2RAGE | - Greater detection of cortical lesions in baseline study and their increase in number with evolution. | |
| PSIR | - Superior detection of cortical lesions and their increase in number with evolution. - Higher detection of spinal cord lesions - Detection of spinal cord gray matter involvement. |
|
| 3D T1 | BRAIN: - Global cerebral atrophy - Cortical atrophy - Deep gray matter atrophy (thalamus/caudate nucleus). - Chronic black holes detection - Slowly expanding lesions (SEL). |
- Difficult application in clinical practice: multiple confounding factors can alter its calculation. - Isometric voxels with 1 × 1 × 1 mm resolution - Use of automatic or semiautomatic post-processing tools. - Use of segmentation techniques. |
| SPINAL CORD: - Global spinal cord atrophy (measurement in the cervical segment). |
- Poor reproducibility | |
| T2* and SWI | - Number of SEL with peripheral iron rim due to the presence of microglia/macrophages | - High magnetic fields (3T and 7T). - Phase imaging |
| - Assessment of iron deposition in basal ganglia | - Quantitative evaluation with R2* mapping or QSM | |
| 3D-T2-FLAIR post contrast | - Detection of ectopic lymphoid follicles. | - Late acquisition at 10–15 min. - Subtracted images |
| MTI | Magnetization transfer ratio (MTR): - MTR reduction in ANWM, ANGM, and T2 lesions. |
- Used in clinical trials to monitor myelin integrity |
| Spectroscopy | - Assessment of NAA (N-acetyl-aspartate) levels. | - No conclusive results |
| DTI | - Alteration of fractional anisotropy (FA) values | - No conclusive results |
PD, Proton Density; FLAIR, fluid-attenuated inversion recovery; DIR, double inversion recovery; MPRAGE, magnetization prepared rapid gradient echo; PSIR, phase-sensitive inversion recovery; SWI, susceptibility-weighted imaging; QSM, quantitative susceptibility mapping; MTI, Magnetization Transfer Imaging; DTI, diffusion tensor imaging.