摘要
目的探讨肝脏扩散加权成像（DWI）的方法。资料与方法将头部DWI序列的参数修正后用于肝脏成像，并以此序列对机器校准纯水水模对32名正常人行b值为0～1000s／mm^2的DWI，测量纯水的表观扩散系数（ADC）值与正常人肝脏信号强度的ADC值。结果纯水ADC值约为2．30×10^-3 mm^2／s。对于正常人，随b值增大肝脏信号强度与ADC值降低，存在负相关性（信号强度与ADC值的相关性分别为r=-0．903，P=0．00；r=-0．795，P=0.00）；b值为50-250s／mm^2时得到的ADC值与变异程度均偏大；b值为300—1000s／mm^2，ADC值变得稳定，变异性减小；但b值为1000s／mm^2时，肝脏信号强度减低，解剖结构显示不清。结论本研究所用的肝脏DWI方法能准确反映水分子的扩散状态，用b值300—800s／mm^2范围，能得到清晰的DWI图像与稳定的ADC值。
Objective To discuss optimal parameters of diffusion weighted imaging （DWI） in liver. Materials and Methods The DWI sequence of brain was modified and then was applied in DWI of liver. DWI was performed in standard water model and 32 healthy volunteers, b values 50 - 1000 s/mm^2 were selected. ADC value of water, ADC value and signal intensity of livers of healthy humans were measured. Results The ADC value of water was 2.30 × 10^-3 mm^2/s. In healthy volunteers, with b values increased, the signal intensity and ADC value of livers decreased. Negative correlation existed in between b value and signal intensity or ADC value （ r = - 0. 903, P = 0. 00; r = - 0. 795, P = 0.00）. ADC value and their variations were big using b 50 - 250 s/mm^2. The ADC value became steady and their variations became small using b 300 - 1000 s/mm^2. But the signal intensity was weak and anatomic structure of liver was not clear when b 1000 s/mm^2 was used. Conclusion Our DWI method can reflect diffusion state water molecules. When b 300 - 800 s/mm^2 is used, clear imaging and steady ADC value can be acquired.
出处
《临床放射学杂志》
CSCD
北大核心
2006年第8期738-741,共4页
Journal of Clinical Radiology
关键词
扩散加权成像
方法研究
水模试验
肝脏
表观扩散系数值
Diffusion weighted imaging Methodological study Experiment of water model Liver ADC value
