弥散峰度成像评估阿尔茨海默病脑部白质纤维束损害

目的 探讨弥散峰度成像(DKI)对于阿尔茨海默病(AD)的诊断价值。方法 对19例AD患者(AD组)和17名健康体检者(对照组)行DKI扫描,测量并比较两组胼胝体膝部、胼胝体压部、双侧前扣带束、双侧后扣带束、双侧上纵束和双侧下枕额束的弥散张量成像(DTI)和DKI参数值,分析各参数与简易精神状态检查量表(MMSE)评分的相关性。结果 AD组胼胝体膝部、压部,双侧前扣带束,双侧后扣带束的各向异性分数(FA)、平均扩散程度(MD)、径向扩散程度(RD)和平均弥散峰度(MK)、径向峰度(RK)、轴向峰度(AK),双侧上纵束和双侧下枕额束MK、RK、AK值与对照组的差异均有统计学意义(P均<0.05);AD组同一患者右前扣带束的FA、MK、AK、RK值,右后扣带束FA值,左上纵束FA、RD、MK、RK值与右侧的差异均有统计学意义(P均<0.05);DTI和DKI参数值与MMSE均具有相关性,胼胝体膝部MK值与MMSE的相关性最高(r=0.55,P<0.05)。结论 DKI可敏感、准确地评价认知障碍的严重程度。

Diffusion kurtosis imaging on evaluation of white matter fiber inpatients with Alzheimer's disease

Objective To explore the value of diffusion kurtosis imaging (DKI) on evaluation of white matter fiber in patients with Alzheimer's disease (AD). Methods Totally 19 patients with AD (AD group) and 17 age-matched normal controls (control group) underwent DKI. The diffusion tensor imaging (DTI) and DKI parameters of white matter fiber tracts (genu and splenium of the corpus callosum, bilateral anterior cingulum and bilateral posterior cingulum, bilateral superior longitudinal fasciculus and inferior fronto-occipiatal fasciculus ) were measured and their correlation with the scores of mini-mental state examination (MMSE) was evaluated. Results Compared with control group, AD group showed significant differences of fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), mean kurtosis (MK), radial kurtosis (RK), axial kurtosis (AK) in bilateral GCC and SCC, bilateral ACG and PCG, MK, RK and AK in bilateral SLF and IFOF. For the same AD patient, compared with the other side, the differences of FA, MK, AK and RK in right ACG, FA in right PCG, FA, RD, MK and RK in left SLF were significant. All DTI and DKI parameters had correlations with MMSE, but MK in GCC was the best (r=0.55, P<0.05). Conclusion The DKI can be used to assess the severity of cognitive deficient sensitively and accurately.