Table 1

The examples of DTI and fMRI studies in SVCI

Study	Subjects	N	Neuroimaging technique	Main findings
Xu et al32	SVCI and normal controls	42	DTI and conventional MRI	DTI detected FA and MD alterations in normal-appearing white matter in SVCI subjects. DTI changes correlated with cognition better than did conventional MRI.
Kim et al37	SVCI	61	DTI and conventional MRI	DTI abnormalities in supratentorial regions correlated with cognitive deficits better than did the ischaemic burden detected by conventional structural MRI.
Lin et al38	SVCI and cognitively normal subjects with subcortical ischaemic vascular disease	50	DTI	SVCI subjects displayed decreased FA and increased MD in all supratentorial regions, which correlated with cognitive dysfunction.
Kim et al39	Subcortical VaD, AD and normal controls	128	DTI	Patients with subcortical VaD showed decreased FA and increased MD in all white matter regions.
Zhou et al40	SVCI and normal controls	36	DTI	SVCI subjects showed lower FA values throughout the brain.
Jung et al41	SVCI and normal controls	169	DTI	SVCI subjects displayed decreased FA in multiple white matter tracts neighbouring and providing connections between grey matter regions.
Shim et al42	SVCI, MCI and normal controls	57	DTI	A greater decrease in FA in the centrum semiovale and parietal regions in SVCI subjects, and the lowest FA in the hippocampus in MCI subjects.
Chen et al43	Subcortical VaD, MCI, AD, FTD and normal controls	85	DTI	White matter abnormalities mainly in the frontal cortical regions, the genu of the corpus callosum and periventricular regions in subcortical VaD subjects.
Zarei et al44	VaD, AD and normal controls	51	DTI	The decreased FA in the transcallosal prefrontal tracts was the most significant biomarker for VaD.
Sun et al55	SVCI and cognitively normal elderly with subcortical ischaemic vascular disease	34	Resting-state fMRI	Decreased DMN FC with frontal, anterior cingulate and temporal regions and increased FC with temporal and parietal regions in SVCI subjects.
Kim et al57	Subcortical VaD, AD, mixed dementia and normal controls	152	Resting-state fMRI	Lower FC in frontal and anterior insular regions in subcortical VaD subjects.
Zhou et al56	SVCI and normal controls	55	Structural and resting-state fMRI	Decreased FC between medial prefrontal cortex and anterior cingulate cortex and supplementary motor area in SVCI subjects.
Yi et al58	SVCI and normal controls	54	Structural and resting-state fMRI	Decreased low-frequency oscillations amplitudes in the anterior part of the DMN and increased amplitudes in the posterior part of the DMN in SVCI subjects.
Yi et al59	SVCI and normal controls	47	Resting-state fMRI	Decreased intramodular connectivity in the prefrontal cortex, parietal cortex, anterior insula and middle cingulate cortex and increased intermodular connectivity in the parietal cortex in SVCI subjects.
Li et al62	Subcortical VaD, AD and normal controls	20	Task-fMRI	The activation in the frontal, parietal and anterior cingulate cortex was reduced in subcortical VaD subjects during performing a Stroop test.
Li et al63	SVCI, subcortical VaD and normal controls	35	Task-fMRI	Mild SVCI subjects displayed significantly increased activation in frontal regions, whereas VaD subjects showed decreased activation during performing a Stroop test.

AD, Alzheimer’s disease; DMN, default mode network; DTI, diffusion tensor imaging; FA, fractional anisotropy; FC, functional connectivity; fMRI, functional MRI; FTD, frontotemporal dementia; MCI, mild cognitive impairment; MD, mean diffusivity; SVCI, subcortical vascular cognitive impairment; VaD, vascular dementia; VCI, vascular cognitive impairment.