正常成人胼胝体年龄相关性变化的DTI参数研究

DTI Parameter study of age-related changes of callosum in normal adults

目的利用扩散张量成像(DTI)技术测量重建的不同年龄正常成人胼胝体纤维的各向异性和扩散特征值,探讨其部分各向异性(FA)和表观扩散系数(ADC)与年龄之间的相关性变化。方法应用Siemens Sonata 1.5 T磁共振扫描仪对102例健康志愿者进行DTI检查,DTI数据经纤维束成像重建出完整的胼胝体纤维,测量胼胝体的FA值和ADC值。结果与青年组比较,中年组和老年组的胼胝体纤维的FA值和ADC值均存在显著性差异,胼胝体纤维的FA值与年龄呈显著性负相关(r=-0.854,P<0.05);胼胝体纤维的ADC值与年龄呈显著性正相关(r=0.625,P<0.05)。结论DTI可无创性反映随年龄的增长,胼胝体纤维的微结构发生的变化,为人类的老年化研究及其临床应用提供依据。

Objective To explore the changes of correlation between the fractional anisotropy （FA） and the apparent diffusion coefficient （ADC） and the age using the fractional anisotropy and the diffusion characteristics values of normal adults of different ages measured and reconstructed with the diffusion tensor imaging （DTI） techniques. Methods The Siemens Sonata 1.5 T MRI scanner was used for the DTI examination of 102 healthy volunteers and the DTI data was reconstructed into complete eallosum fibers through the fiber bundle imaging. The FA value and ADC value of the callosum were mea- sured. Results Compared with the young group, the middle-aged group and the elder group were significantly different in the FA value and the ADC value of the eallosum fibers. The FA value of the eallosum fibers had a significantly negative correlation with the age （r = -0.854, P 〈 0.05）, and the ADC value of the eallosum fibers had a significantly positive cor- relation with the age （r = 0.625, P 〈 0.05）. Conclusion DTI is non-invasive and can reflect the microstructural changes of the callosum fibers with the growth of age, which provides basis for the researches on human aging and their clinical application.