[Diffusion tensor imaging of elderly leukoaraiosis and its correlation with cognitive function].

ABSTRACT

OBJECTIVE: To apply diffusion tensor imaging (DTI) for investigating the correlation between leukoaraiosis (LA) lesion's fraction anisotropy (FA) as well as average diffusion coefficient (DCavg) and LA severity, so as to explore DTI changes in microstructure of white marrow with normal ordinary MRI and its correlation with cognitive function. METHODS: Sixty LA patients and 30 healthy elderly people accepted DTI examination to detect the value of DCavg and FA of LA lesion and normal white marrow. The Mini-Mental State Examination (MMSE) was used for assessing cognitive function. RESULTS: LA severity (0 grade to 3 grade) was positively associated with DCavg, i.e. the more severe was LA, the higher DCavg was (0.66 +/- 0.05 to 1.09 +/- 0.06, P < 0.05); and it was negatively associated with FA, i.e. the more severe was LA, the lower FA was (0.42 +/- 0.04 to 0.26 +/- 0.03, P < 0.05). Neuropsychology tests (Mini-Mental State Examination, MMSE) had a significant relationship with DCavg and FA of normal appearing white matter (NAWM) in LA patients (P < 0.05), especially in anterior horn (Pearson Correlation Coefficient 0.422, P < 0.05) and in centrum semiovale (Pearson Correlation Coefficient -0.495, P < 0.01). CONCLUSIONS: In DTI examination, DCavg and FA of LA displays characteristic changes. Therefore, DTI can detect the macrostructaral changes of white marrow with normal MRI and these changes are related to cognitive function.