胼胝体磁共振弥散张量成像技术参数研究
The parameters of magnetic resonance diffusion tensor imaging in corpus callosum
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摘要: 目的:探讨胼胝体磁共振弥散张量成像(DTI)临床应用的扫描参数。方法:对30名健康成年人行头部矢状位DTI,比较不同b值、层厚/层间距、扩散敏感梯度方向3个扫描参数对各向异性分数(FA)图像质量的影响。结果:不同的扫描参数对FA图像质量的影响各不相同。中间位b值(b=1000 s/mm²)时FA图像质量最佳,高b值(b=1500 s/mm²)FA图像噪声大,低b值(b=500 s/mm²)FA图像对比度差。层厚/层间距越大,FA图像信噪比越高,但会遗漏细微结构的显示。13个与25个扩散敏感梯度方向FA图像质量差异无统计学意义(P0.05),6个扩散敏感梯度方向FA图像质量较差。结论:临床实际应用中,胼胝体矢状位DTI的适用扫描参数为b=1000 s/mm²、5 mm/0 mm层厚/层间距、13个扩散敏感梯度方向。Abstract: Objective:To explore the technical parameters of magnetic resonance diffusion tensor imaging(DTI) in corpus callosum. Methods:The DTI of the sagittal plane were detected in 30 nomarl brains.The effects of b value,slice thickness/interlamellar spacing and diffusion sensitive gradient direction on fractional anisotropy(FA) image quality were compared.Results:Different parameters had different effects on FA image quality.The quality of FA image was best when b value was middle(b = 1000 s/mm²),FA image noise was large at the high b value(b = 1500 s/mm²),and the contrast of FA image was poor at the low b value(b = 500 s/mm²).The signal to noise ratio was high with slice thickness/interlamellar spacing increasing,the subtle structure was easy to miss.The differences of FA image qualities at 13 and 25 diffusion sensitive gradient directions statistical significance (P 0.05).The FA image quality at 6 diffusion sensitive gradient direction was worse hadno.Conclusions:The 1000 s/mm² of b value,5 mm/0 mm of slice thickness and 15 diffusion sensitive gradient directions are suitable for DTI of corpus callosum in the sagittal head in clinic.