【摘要】 目的比较扩散张量成像中施加不同数量的梯度磁场方向对扩散的各向异性(FA)和表观扩散系数(ADC)参数的影响。资料与方法对24名正常人进行3.0 T磁共振扩散张量成像扫描,分别施加6个和25个方向的扩散敏感梯度磁场。分别测得2个梯度方向所获得FA图和ADC图的内囊前、后肢及胼胝体膝部、压部白质的FA与ADC值,进行比较。结果在其他扫描参数不变的情况下(b=01、000 s/mm2),6个方向与25个方向,相应部位的FA和ADC值的两组数据无显著差异。结论磁共振扫描选择扩散张量成像扫描参数时,在不影响各定量值测量的情况下,应尽量减少扫描时间,6个方向是扩散张量成像的较好选择。更多还原

【Abstract】 Objective To compare the influence of different directions of gradients on FA and ADC in diffusion tensor imaging(DTI).Materials and Methods 24 healthy volunteers were examined with a 3.0-T MRI.Fractional anisotropy(FA) and the Apparent Diffusion Coefficient(ADC) from bilateral internal capsule,the genu and spenium of corpus callosum with 6 directions and 25 directions of gradient were measured and compared.Results Without changing of other scan parameters,FA and ADC from ROIs of bilateral hemisphere with 6 and 25 directions were no significant difference in one subject.Conclusion The 6 directions and 25 directions of gradients does not influence measures of FA and ADC of DTI.It is desirable to use 6 directions of measurements to reduce scanning time.更多还原