早期脑白质弥散张量与磁化传递成像在诊断双相情感障碍Ⅰ型中的应用

The applications of diffusion tensor imaging and magnetization transfer imaging in evaluating white matter abnormalities in early stage of bipolar disorder

目的采用弥散张量成像(DTI)与磁化传递成像(MTI)探讨双相情感障碍(BD)Ⅰ型早期患者脑白质微观结构变化,为早期诊断BD提供客观依据。方法对17例病程小于2年的早期BDⅠ型患者(观察组)及17例正常对照者(对照组)进行DTI及MTI成像,测量双侧前扣带回、额叶白质及胼胝体等结构的各向异性指数(FA)、表观弥散系数(ADC)以及磁化传递率(MTR),并进行对比分析。结果与对照组比较,观察组右侧前扣带回膝前部FA值降低(P=0.015),ADC值增高(P=0.049),左侧前扣带回膝下部、背后部、右侧前扣带回背后部以及胼胝体体部FA值明显降低,差异有统计学意义(P<0.05);观察组各感兴趣区的MTR值与对照组差异无统计学意义(P>0.05)。结论 BDⅠ型早期脑白质异常主要位于前扣带回和胼胝体体部,FA及ADC值可早期反映BD脑白质结构异常,而MTR尚不能检测早期BD脑白质轻微变化。

Objective To investigate white matter microstructural changes in early stage of bipolar disorder （BD） using diffusion tensor imaging （DTI） and magnetization transfer imaging （MTI）, in order to provide evidences for early diagnosis of BD. Methods DTI and MTI were performed in 17 BD I patients with course of disease less than 2 years and 17 normal controls. Fractional anisotropy （FA）, apparent diffusion coefficient （ADC） and magnetic transfer ratio （MTR） were measured in bilateral prefrontal white matter, anterior cingutate cortex and corpus callosum for comparison. Results Significant reduction in FA in left subgenu - ACC, posterior of dorsal ACC, right anterior genu - ACC and body of corpus callosnm and increase in ADC in right posterior of dorsal - ACC were recorded in the patients （ P 〈 0. 05 ）. No significant difference was revealed in MTR between patients and normal controls. Conclusion Abnormalities in early stage of BD I patients mainly locate in anterior cingutate cortex and corpus callosum. FA and ADC can be used to monitor white matter abnormalities in early stage of BD patients, while MTR can not detect mild changes in white matter.