Table 2.
Diffusion tensor imaging studies of ASD children.
| Reference | Age range | Brain regions | Methods | Findings in ASD group |
|---|---|---|---|---|
| Sundaram et al. (2008) [91] | 2–7 years | Association fibers in frontal lobes | DT; ROI; MANCOVA; DTIstudio | ↑ MD in short and long-range fibers; ↓ FA in short-range fibers |
| Hong et al. (2011) [92] | 7–11 years | Corpus callosum (CC) | DT; ROI; WM density and volume; FSL; SPSS | ↓ WM density in the anterior third of the CC; ↑ MD in the anterior third of the CC |
| Nagae et al. (2012) [93] | 7–18 years (+/-language impairment) | Superior longitudinal fasciculus (SLF); corticospinal tract (CST) | DT; GLM; SPSS; DTIstudio | ↑ MD in CST (ASD without language impairment); ↑ MD in left SLF (ASD with language impairment) |
| Wolff et al. (2012) [94] | (Longitudinal) 6–7 months; 12–13 months; 23–25 months | Global main tracts | DT; ROI; DTIprep; SAS | ↑ FA in CC body, left fornix, inferior longitudinal fasciculus, uncinate fasciculus (6 mo); no difference in FA (12 mo); ↓ FA in left anterior internal capsule and anterior thalamic radiation (24 mo) |
| Nair et al. (2013) [95] | 9–17 years | Cortex; thalamus | PT; ROI; FSL; T-test | ↑ MD in thalamo-cortical connectivity; negative correlation between fronto-thalamic FA and ADOS score |
| Joseph et al. (2014) [96] | 4–6 years | Arcuate fasciculus | PT; ANOVA; FSL | ↓ RD of arcuate fasciculus |
| Cheung et al. (2009) [97] | 6–14 years | Global white matter | VBM; SPM; GLM; SPSS | ↓ FA in bilateral prefrontal and temporal regions; ↑ FA in SLF and left occipital lobe |
| Ke et al. (2009) [98] | 6–11 years | Regional frontal and temporal gyri | VBM; SPM | ↓ WM density in right frontal and left parietal lobe; ↓ FA in frontal left temporal lobe |
| Barnea-Goraly et al. (2010) [99] | 9–14 years | Regional white matter | VBM; FSL | ↓ FA in frontal, temporal and parietal lobes |
| Poustka et al. (2012) [100] | 8–12 years | Fornix; SLF; uncinate fasciculus; CC | VBM; DT; SPM | ↓ FA in the uncinate fasciculus and right SLF; negative correlation between FA and severity of ASD symptoms |
| Peterson et al. (2015) [101] | 9–12 years | Global white matter | ROI; ANCOVA; LDDMM | ↑ MD through left hemisphere, especially outer-zone of cortical WM |
| Kumar et al. (2010) [106] | 2–9 years | Global white matter tracts | TBSS; DT; ANOVA; FSL | ↓ FA in right uncinate fasciculus, right cingulum, and CC; ↑ MD in right arcuate fasciculus |
| Weinstein et al. (2011) [107] | 2–4 years | Global white matter tracts | TBSS; DT; FSL | ↑ FA in CC, left SLF and bilateral cingulum |
| Jou et al. (2011) [88] | 7–15 years | Global white matter tracts | TBSS; FSL; SPSS | ↓ FA in general association and projection tracts |
| Shukla et al. (2010) [85] | 12–13 years | CC; internal capsule; middle cerebellar peduncle | TBSS; ROI; VBM; FSL; SPM | ↓ FA ↑ MD for global white matter tracts |
| Walker et al. (2012) [108] | 3–7 years | Global white matter tracts | TBSS; FSL | ↓ FA in various areas; ↑ MD in posterior brain regions |
WM, white matter; GM, grey matter; RD, radial diffusivity; FA, fractional anisotropy; MD, mean diffusivity; ROI, region of interest; TBSS, tract-based spatial statistics; DT, deterministic tractography; PT, probabilistic tractography; GLM, general linear models; ANOVA, analysis of variances; LDDMM, large deformation diffeomorphic metric mapping; VBM, voxel-based morphometry; SPM, FSL, DTIstudio, DTIprep, SPSS, and SAS are data analysis packages.