MR扩散张量成像在阿尔茨海默病评估中的作用

The role of MR-diffusion tensor imaging in the assessment of Alzheimer′s disease

目的 应用MR扩散张量成像技术 (DTI)评价阿尔茨海默病 (AD)患者脑白质有无损伤及其损伤的部位。方法 对 2 4例AD患者和 2 1例年龄匹配的健康老年人的脑部进行MR常规和DTI扫描 ,对双侧颞、顶、额叶及扣带的平均扩散系数 (ADC)和各向异性分数 (FA)的平均值进行测量并统计。结果 AD患者额叶、顶叶、颞叶、扣带的FA值分别为 0 37± 0 0 6 ,0 32± 0 0 5 ,0 2 6± 0 0 3,0 4 7±0 0 9,ADC值分别为 9 5 0e 1 0± 2 0 2e 1 0 ,1 0 5 5e 1 0± 1 4 3e 1 0 ,1 1 4 5e 1 0± 0 76e 1 0 ,1 0 1 0e 1 0±2 1 8e 1 0 ;健康老年人相应部位的FA值分别为 0 4 4± 0 0 6 ,0 38± 0 0 5 ,0 32± 0 0 5 ,0 5 6± 0 0 6 ,ADC值分别为 8 75e 1 0± 1 6 3e 1 0 ,9 83e 1 0± 0 99e 1 0 ,1 1 1 3e 1 0± 0 78e 1 0 ,8 2 8e 1 0± 1 6 5e 1 0。AD患者的额叶、顶叶、颞叶及扣带部位的FA值较健康老年人降低 (P≤ 0 0 0 6 ) ,扣带部位的ADC值较健康老年人升高 (P≤ 0 0 0 6 ) ,而额叶、顶叶、颞叶的ADC值在两组之间差异无统计学意义 (P >0 0 0 6 )。结论 DTI检测出AD额叶、颞叶、顶叶及扣带部位脑白质有损伤 ,提示AD患者不仅有灰质病变 ,并且脑白质亦存在异常。

Objective To evaluate the possible white matter damage and to define the location of the damage in Alzheimer′s disease (AD) with diffusion tensor imaging (DTI). Methods Twenty-four AD patients and twenty-one age-matched healthy volunteers received conventional and DTI scanning.The ADC and FA of white matter in temporal, parietal, frontal lobe and cingulum were measured respectively and the data underwent postprocessing.Results FA value of the whiter matter in frontal, parietal, temporal and cingulum in AD patients was 0.37±0.06, 0.32±0.05, 0.26±0.03, and 0.47±0.09, respectively, and ADC value was 9.50 e-10±2.02 e-10, 10.55 e-10±1.43 e-10, 11.45 e-10±0.76 e-10, and 10.10 e-10±2.18 e-10, respectively;FA value of the same corresponding regions in control was 0.44±0.06, 0.38±0.05, 0.32±0.05, and 0.56±0.06, respectively, and ADC value was 8.75 e-10± 1.63 e-10, 9.83 e-10±0.99 e-10, 11.13 e-10±0.78 e-10, and 8.28 e-10±1.65 e-10, respectively.FA value of the whiter matter in frontal, parietal, temporal, lobe and cingulum decreased (P≤0.006) and ADC value increased in cingulum white matter (P≤0.006) in AD patients.Conclusion DTI could reveal the damage in white matter of frontal, temporal, parietal lobe and cingulum.It suggested that not only the gray matter is injuried, but also the white matter is abnormal in AD patients.