3.0T磁共振DWI在胃癌诊断中弥散敏感系数选择的初步研究

Study on Diffusion Sensitive Coefficients of 3.0T Magnetic Resonance DWI in the Diagnosis of Gastric Cancer

目的初步探讨3.0T磁共振弥散加权成像(DWI)在胃癌诊断中合适的弥散敏感系数(b值)的选择。方法回顾性分析了76例经病理证实的胃癌病变患者的MRI原始资料,包括常规MRI和不同b值的DWI(b值为400 s/mm^2、600 s/mm^2、800 s/mm^2、1 000 s/mm^2)。运用Philips ADW 4.2工作站,分析记录不同b值胃癌与正常胃壁的ADC值,计算不同b值时测得的胃癌ADC值与正常胃壁ADC值的差异,最后运用统计学分析确定合适的b值。结果当b=0,400 s/mm^2、600 s/mm^2、800 s/mm^2、1 000 s/mm^2时,胃癌ADC值平均值分别为:(1.637±0.796)、(1.299±0.625)、(1.356±0.538)、(1.209±0.510)(×10^(-3) s/mm^2),均小于正常胃壁ADC值平均值:(3.042±1.562)、(2.644±0.807)、(2.321±0.689)、(2.065±0.496)(×10^(-3) s/mm^2),之间差异有统计学意义(P<0.05)。其中b=0,400s/mm^2、600 s/mm^2时胃癌与正常胃壁的ADC值均值差异有统计学意义(P<0.01)。结论在3.0T磁共振弥散加权诊断胃癌时,b值为600s/mm^2时胃癌与正常胃壁ADC值差异显著,具有更高的敏感性和特异性,且受血流灌注及T2投射效应影响更小,测得的ADC值更接近组织的真实扩散值,可作为较合适的成像b值。

Objective Preliminary research of 3.0T magnetic resonance DWI in the suitable choice of dispersion sensitivity coefficient（b） in the diagnosis of gastric cancer. Methods First, make a retrospective analysis for MRI source material of patients with gastric cancer confirmed by pathology in 76 cases, including routine MRI and DWI of different b（b value 400 s/mm^2, 600 s/mm^2, 800 s/mm^2, 1 000 s/mm^2）. Second, employ the workstation of Philips ADW 4.2 to analyze and record gastric cancer of different b and ADC value of normal gastric wall. Then, calculate the difference between ADC value of gastric cancer of different b value and ADC value of normal gastric wall. And finally apply the statistical analysis to ensure the suitable b. Results When b=0, 400 s/mm^2, 600 s/mm^2, 800 s/mm^2, 1 000 s/mm^2, the average value of ADC value of gastric cancer is：（1.637±0.796）,（1.299±0.625）,（1.356±0.538）,（1.209±0.510）（×10^（-3） s/mm^2）, totally smaller than the average value of ADC value of normal gastric wall, that is,（3.042±1.562）,（2.644±0.807）,（2.321±0.689）,（2.065±0.496）（×10^（-3） s/mm^2）, there is statistical significance between them（P〈0.05）. When b=0, 400 s/mm^2, 600 s/mm^2, the difference is apparent in mean difference between gastric cancer and ADC value of normal gastric wall（P〈0.01）. Conclusion Diagnose gastric cancer using diffusion-weighted imaging, when b is 600 s/mm^2, the difference is apparent between gastric cancer and ADC value of normal gastric wall with higher sensitivity and specificity. Have less influence of blood perfusion and T2 projection effect. The measure of ADC value is closer to the real diffusion value of the tissue. It can be the suitable b of imaging.