Table 1.
Surrogate quantitative MR markers indicating different features of neurodegeneration. The main markers corresponding to the underlying pathology and the sequences needed are indicated.
| Microstructure-biochemical profile | Macrostructure | |||
|---|---|---|---|---|
| Marker | Sequence | Marker | Sequence | |
| Neuronal/axonal loss: degeneration | ADC, rTrace(D), MD, AD | DW Images | T2 signal intensity | T2-w sequences |
| NAA | 1H-MRS | Area, diameter, volume | Volumetric T1 sequences | |
| MTR | MTI (T1 or PD-w sequence with off resonance saturation) | |||
|
| ||||
| Glial reaction: gliosis | mI | 1H-MRS | ||
|
| ||||
| Myelin disruption | FA, RD | DW Images | T2 signal intensity | T2-w sequences |
| Cho | 1H-MRS | Volume | Volumetric T1 sequences | |
| MTR | MTI (T1 or PD-w sequence with off resonance saturation) | |||
|
| ||||
| Iron content | T2∗/R2∗ values | T2∗/R2∗-w sequence | ||
| Phase shift values | SWI phase images | |||
ADC: apparent diffusion coefficient; MD: mean diffusivity; AD: axial diffusivity; DW: diffusion weighted; NAA: N-acetyl-aspartate; 1H-MRS: proton-MR spectroscopy; MTR: magnetization transfer ratio; MTI: magnetization transfer imaging; PD: proton density; mI: myo-inositol; FA: fractional anisotropy; RD: radial diffusivity; Cho: choline; SWI: susceptibility-weighted imaging.