Scanning methods and altered fractional anisotropy regions of the 15 studies included in this meta-analysis
| Study | Field, T (coil, channels) | Acquisition voxel, mm3 | No. of directions | Coordinate system | No. of coordinates | Type of analysis | Significant change in FA |
|---|---|---|---|---|---|---|---|
| Arnold et al.13 | 1.5 (8) | 2.5 × 2.5 × 2.5 | 30 | — | 0 | VBA | — |
| Choi et al.41 | 3 (12) | 2 × 2 × 2 | 60 | — | 0 | VBA, TBSS | — |
| Han et al.26 | 3 (12) | 1.8 × 1.8 × 3.0 | 20 | MNI | 1 | TBSS | Decrease observed in the body of the CC |
| Hayashi et al.42 | 3 (8) | 1.02 × 1.02 × 4 | 25 | — | 0 | TBSS | — |
| Jia et al.22 | 3 (8) | 1 × 1 × 3 | 15 | MNI | 4 | VBA | Both decreases and increases observed in the bilateral parietal lobe (subgyral), R frontal lobe (paracentral lobule) and R cerebellum (anterior lobe) |
| Korgaonkar et al.44 | 3 (8) | 1.72 × 1.72 × 2.5 | 42 | — | 0 | TBSS | — |
| Lai and Wu28 | 3 (NA) | 2 × 2 × 2 | 30 | MNI | 2 | TBSS | Both decreases and increases observed in the L SLF and R anterior thalamic radiation |
| Ma et al.23 | 1.5 (birdcage) | 1.875 × 1.875 × 4 | 13 | Tal | 4 | VBA | Both decreases and increases observed in the R middle frontal gyrus, L lateral occipitotemporal gyrus, subgyral white matter of the R parietal lobe and R angular gyrus |
| Olvet et al.27 | 3 (8) | 0.95 × 0.95 × 3 | 25 | MNI | 5 | TBSS | Both decreases and increases observed in the R body of the CC, L inferior fronto-occipital fasciculus, R anterior thalamic radiation, R inferior longitudinal fasciculus and R cingulum |
| Ouyang et al.15 | 1.5 (birdcage) | 1.875 × 1.875 × 4 | 13 | MNI | 6 | VBA | Both decreases and increases observed in the bilateral medial frontal gyri, R subgyral frontal and temporal lobes, L middle frontal gyri and L cingulate gyrus |
| Tha et al.24 | 1.5 (NA) | 1.875 × 1.875 × 5 | 12 | MNI | 9 | VBA | Both decreases and increases observed in the bilateral frontal gyrus, bilateral anterior limbs of the internal capsule and L putamen, mediodorsal nucleus of the R thalamus, anterior and superior aspect of bilateral cerebellar hemispheres |
| Wang et al.25 | 3 (NA) | 0.9375 × 0.9375 × 5 | 42 | MNI | 4 | VBA | Decreases observed in the R cuneus gyrus, and increases observed in the R thalamus, R postcentral gyrus and cerebellar vermis |
| Wu et al.29 | 1.5 (NA) | 0.94 × 0.94 × 4 | 13 | MNI | 3 | VBA | Decreases observed in the R SLF within the frontal lobe, R middle frontal and L inferior parietal lobe |
| Zhu et al.43 | 1.5 (NA) | 1.875 × 1.875 × 4 | 13 | MNI | 3 | TBSS | Decreases observed in the L anterior limb of the internal capsule and R parahippocampal gyrus, and both decreases and increases observed in the L posterior cingulate cortex |
| Zuo et al.30 | 1.5 (NA) | 1 × 1 × 4 | 25 | MNI | 2 | TBSS | Decreases observed in the L centre portion of the SLF and L premotor area (BA 6) |
BA = Brodmann area; CC = corpus callosum; DTI = diffusion tensor imaging; FA = fractional anisotropy; L = left; MDD = major depressive disorder; MNI = Montreal Neurological Institute; NA = not available; R = right; Tal = Talairach; SLF = superior longitudinal fasciculus; TBSS = tract-based spatial statistics; VBA = voxel-based analysis.