Table 2.
Overview of the quantitative microstructural indices and their interpretation in white matter.
| MRI modality | Index | Apparent white matter property | Hypothesised changes in central obesity |
|---|---|---|---|
| Diffusion NODDI | ICSF | Axon density | Reduction |
| ODI | Axon dispersion | Increase | |
| ISOSF | Free water | Increase | |
| qMT | MPF | Myelin Neuroinflammation | Reduction |
| kf | Neuroinflammation Mitochondrial metabolism | Increase in acute inflammation (Harrison et al., 2015); Reduction in low-level inflammation (Johnson et al., 2012) |
Abbreviations: ICSF = intracellular signal fraction, ISOSF = isotropic signal fraction, kf = forward exchange rate, MPF = macromolecular proton fraction, NODDI = neurite orientation dispersion and density imaging, ODI = orientation dispersion index, qMT = quantitative magnetization transfer.