扩散峰度成像与扩散张量成像诊断帕金森病患者脑白质损伤的比较研究

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

目的比较扩散张量成像(DTI)与扩散峰度成像(DKI)诊断帕金森病(PD)患者脑白质损伤的价值。方法对45例PD患者和25例健康对照人群(对照组)进行磁共振DTI及DKI检查扫描,根据蒙特利尔认知评估量表(MoCA)评分将PD患者分为认知功能未受损者20例(PD-Cu组)和轻度认知障碍(MCI)者25例(PD-MCI组)。应用FMRIB′s Software Library(FSL)软件中的dtifit功能计算各向异性分数(FA)等DTI相关标量指标;应用扩散峰度估计器(DKE)计算平均峰度(MK)等DKI相关标量指标;通过基于纤维束的空间统计分析(TBSS)方法分别比较PD-Cu组与对照组、PD-MCI组与PD-Cu组之间的脑白质纤维束差异。结果PD-Cu组与PD-MCI组患者的简易智力状况检查量表(MMSE)评分、MoCA评分比较,差异有统计学意义(P<0.05)。与对照组比较,PD-Cu组脑白质纤维束FA值、MK值降低,差异有统计学意义(P<0.05);与PD-Cu组比较,PD-MCI组脑白质纤维束FA值、MK值降低,差异有统计学意义(P<0.05);PD患者脑白质纤维束MK异常脑区多于FA异常脑区。结论DKI和DTI对早期诊断PD认知障碍均有一定的潜在价值,但相较于DTI技术,DKI技术或可更为敏感地检测出PD患者相关脑白质纤维束的损害。

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.