Table 2.
Summary of MR techniques in MS assessment. Table summarizing MRS and other MR techniques suitable for MS assessment and typical disease manifestation.
| MS Manifestation | MRS Techniques | Other MR Techniques | |
|---|---|---|---|
| demyelination |
1H MRS: ↑tCho 31P MRS: ↑PDE, ↓[Mg2+] |
↑tCho in DGM PDE > PME (mainly in WM) ↓[Mg2+] (in MS lesions) |
MRI-T2 lesion load MR-relaxometry: ↑T2 magnetization transfer |
| remyelination |
1H MRS: ↑tCho 31P MRS: ↑PME |
PME > PDE (mainly in WM) | |
| neuro-axonal loss |
1H MRS: ↓tNAA, ↑Glx, ↓GABA 31P MRS: ↑PCr, ↓ATP, ↓[Mg2+] |
↓tNAA (in MS lesions, NAWM, cortical GM)↑Glx excitotoxicity (mainly in WM) ↓GABA (mainly in the hippocampus and sensorimotor cortex) ↑PCr and ↑PCr/β-ATP ↓[Mg2+] (mainly in WM) |
diffusion: ↑ACD, ↓FA MRI: T1 hypointensities MRI: T2 hyperintensities MR-relaxometry: ↑T2 |
| gliosis, inflammation | 1H MRS: ↑tCho and ↑mIns | ↑tCho (in MS lesions) ↑mIns (in MS lesions, NAWM) |
perfusion: hyperintensities Gd-T1 hyperintensities |
| cell debris accumulation |
1H MRS: ↑tCho 31P MRS: ↑PDE |
↑tCho (in MS lesions) | magnetization transfer |
| cell energy failure | 31P MRS: ↑PCr, ↓ATP | ↑PCr and ↑PCr/β-ATP (in acute MS lesions) | functional MRI |
| BBB permeability | unknown | unknown | Gd-T1 hyperintensities |
| iron deposits | unknown | unknown | MR-relaxometry: ↓T2
SWI: hyperintensities |
Abbreviations: ACD: Apparent diffusion coefficient, ATP/mainly β-ATP: adenosine triphosphates, DGM: deep gray matter, FA: fractional anisotropy, GABA: γ-aminobutyric acid, Glx: glutamate and glutamine, [Mg2+]: intracellular Mg2+ concentration, mIns: myoInositol, NAWM: normal-appearing WM, PCr: phosphocreatine, PDE: phosphodiesters, PME: phosphomonoesters, SWI: susceptibility weighted imaging, tCho: total choline, tNAA: total N-acetyl-aspartate, WM: white matter; ↓: decreased, ↑: increased.