Diffusion kurtosis imaging versus diffusion tensor imaging in diagnosing cerebral white matter damage of patients with Parkinson′s disease

Objective  To compare the value of diffusion tensor imaging (DTI) and diffusion kurtosis imaging (DKI) in diagnosing cerebral white matter damage of patients with Parkinson′s disease (PD).

Methods  Magnetic resonance DTI and DKI examination scans were performed for 45 PD patients and 25 healthy controls (control group), and PD patients were divided into PD-Cu group (20 cases with cognitively unimpaired PD) and PD-MCI group 25 cases with mild cognitive impairment (MCI) according to the score of the Montreal Cognitive Assessment (MoCA). DTI-related scalar indicators such as fractional anisotropy (FA) value were calculated by the dtifit function in FMRIB′s Software Library(FSL); DKI-related scalar indicators such as mean kurtosis (MK) were calculated by diffusion kurtosis estimator(DKE); the tract-based spatial statistics (TBSS) method was used to respectively compare the differences in cerebral white matter fiber tracts between the PD-Cu group and control group and between the PD-MCI group and the PD-Cu group.

Results  There were significant differences in the scores of the Mini-mental State Examination (MMSE) and MoCA between PD-Cu group and PD-MCI group (P < 0.05). Compared with the control group, the FA value and MK value of cerebral white matter fiber tracts in the PD-Cu group decreased significantly (P < 0.05);compared with the PD-Cu group, the FA value and MK value of cerebral white matter fiber tracts in the PD-MCI group decreased significantly (P < 0.05); the abnormal brain areas of MK were more than those of FA in the cerebral white matter fiber tracts of PD patients.

Conclusion  Both DKI and DTI have certain potential value in the early diagnosis of cognitive impairment in PD, but compared with DTI technology, DKI technology may be more sensitive to detect the damage of related cerebral white matter fiber tracts in PD patients.