皮层下动脉硬化性脑病患者的3.0-T磁共振DTI技术FA值与认知功能障碍相关性分析

Correlation between fractional anisotropy values of diffusion tensor imaging with 3.0-T MRI and cognitive impairment in patients with subcortical arteriosclerotic encephalopathy

目的:探讨3.0 T磁共振扩散张量成像(diffusion tensor imaging,DTI)技术各向异性(fraction anisotropy,FA)值与皮层下动脉硬化性脑病(subcortical arteriosclerotic encephalopathy,SAE)患者认知功能障碍之间的相关性。方法:收集经临床及影像学诊断为SAE的患者55例及健康老年志愿者30例,均进行常规MRI及DTI扫描,并分别于脑室前后角及半卵圆中心病灶区域(正常对照组相应区域)测量FA值。结果:SAE患者各病灶区FA值与正常对照组相应部位FA值的差异具有统计学意义(P<0.05),即:SAE患者各病灶区FA值较正常对照组相应部位FA值低;不同程度认知功能障碍的SAE患者的相应病变部位FA值差异有统计学意义(P<0.05),即认知功能障碍程度越重,SAE患者的相应病变部位FA值越低;SAE患者的简易精神量表(Mini-mental State Examination,MMSE)评分与患者侧脑室前后角及半卵圆中心病变区域FA值呈显著正相关(相关系数:r左半=0.623,r右半=0.653,r左后=0.717,r右后=0.745,r左前=0.810,r右前=0.835)。结论:运用3.0 T磁共振DTI技术,通过对SAE患者特定脑白质病变区域的FA值的测定,能够在一定程度上的反映SAE患者的神经纤维损害程度,间接反映SAE患者病灶区FA值与认知功能障碍之间的关系。

Objective： To investigate the correlation between fractional anisotropy （FA） values of diffusion tensor imaging （DTI） with 3.0-T magnetic resonance imaging （MRI） and cognitive impairment in patients with subcortical arteriosclerotic eneephalopathy （SAE）. Methods： Fifty-five patients with SAE diagnosed by clinical examination and medical imaging were included in the study, and thirty healthy elderly volunteers were considered as controls. All subjects underwent routine brain MRI and DTI scans. The FA values at lesions in the anterior and posterior horns of the lateral ventricle and the centrum semiovale were measured, and the FA values of corresponding areas in controls were also measured. Results： The SAE group had significantly lower FA values than the control group （P 〈 0.05）. The SAE patients with different levels of cognitive impairment had significantly different FA values in cerebral lesions （P 〈 0.05）, that is, the higher levels of cognitive impairment were associated with lower FA values. In SAE patients, the Mini-Mental State Examination （MMSE） score was significantly positively correlated with the FA values of lesions in the anterior and posterior horns of the lateral ventricle and the centrum semiovale （correlation coefficient： Heft = 0.623, night = 0.653, rleft-posterior = 0.717,rright-posterior = 0.745, deft-anterior = 0.810, rright-anterior = 0.835）. Conclusions： Measuring the FA values at specific white matter lesions based on DTI with 3.0-T MRI can accurately predict the levels of nerve fiber damage in SAE patients, and indirectly predict the correlation between FA values in cerebral lesions and cognitive impairment.