Whole brain diffusion tensor imaging histogram analysis in vascular cognitive impairment.

BACKGROUND: Studies were carried out to detect brain tissue damage in patients with vascular cognitive impairment (VCI) using diffusion tensor imaging (DTI) histogram analysis, and to determine the correlations between DTI histogram-derived measures and Mini-Mental State Examination (MMSE) scores.

METHODS: Conventional MRI and DTI scans were performed on 19 patients with VCI, 19 age- and sex-matched post-stroke patients without cognitive impairment (stroke group) and 19 cognitively normal subjects (CN group). Histograms of the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) of the whole brain were analyzed.

RESULTS: Analysis showed that the patterns of the whole brain ADC and FA histograms of the VCI group differed from those of the stroke and CN groups. Compared with those of the two control groups, the mean FA value was significantly lower and the FA histogram peak height was higher in the VCI group. However, the patterns of the whole brain ADC and FA histograms in the stroke group were similar to those of the CN group, and there were no significant differences in any of the DTI histogram-derived measures between these two groups. The mean FA value, the FA histogram peak height, and the FA histogram peak location in VCI patients correlated with the MMSE scores.

CONCLUSIONS: Our findings suggest that VCI leads to abnormal diffusion in brain tissue, and that DTI histogram-derived measures might be used to monitor the severity of cognitive impairment in this disease.