体素内不相干运动对不同Ki-67指数胃癌的诊断价值

Correlation between IVIM parameters and Ki-67 index in gastric cancer

目的探讨体素内不相干运动(intravoxel incoherent motion,IVIM)参数与胃癌Ki-67表达的相关性。方法选取我院经手术病理证实的胃癌(gastric cancer,GC)患者54例,受试者术前均接受3.0T MRI常规及IVIM扫描,分别测量并计算患者的IVIM参数,包括ADC、真扩散系数(pure water diffusion coefficient,D)、灌注分数(perfusion fraction,f)及伪扩散系数(pseudo-diffusion coefficient,D^(*)),同时获取术后胃癌的免疫组化Ki-67的表达值。依据Ki-67指数的表达值将患者分为低表达组(Ki-67指数<50%,25例)与高表达组(Ki-67指数≥50%,29例)。组间参数的差异比较采用ANOVA检验(正态分布)或Kruskal-Wallis H检验(非正态分布);使用Spearman相关性分析针对参数与Ki-67表达进行相关性分析;应用ROC曲线分析参数的诊断效率。结果除D*外,低表达组ADC、D、f值均高于高表达组(P<0.05);ADC、D及f与Ki-67的表达呈负相关,D与Ki-67相关性最高。ADC、D、f的AUC值分别为0.919、0.923、0.884;阈值分别为12.00、10.60、2.93;敏感性分别为91.67%、95.83%、87.50%;特异性分别为83.33%、87.50%、81.82%。结论除D^(*)值外,ADC、D和f值与胃癌的Ki-67表达水平呈负相关。因此,IVIM判断胃癌增殖性的效果优于DWI,并为判断预后提供更加完善的信息。

Objective To investigate correlation between intravoxel incoherent motion(IVIM)parameters and Ki-67 expression in gastric cancer.Method 54 patients with gastric cancer(GC)were confirmed by surgery and pathological results in our hospital were selected.The subjects underwent routine 3.0T MRI and IVIM scans before surgery and IVIM parameters of each patient were measured and calculated including ADC,pure water diffusion coefficient(D),perfusion fraction(f),and pseudo diffusion coefficient(D^(*)).Simultaneously,the expression value of Ki-67 immunohistochemistry was obtained in gastric cancer.According to expression value of Ki-67 index,patients were divided into two groups:low expression group(Ki-67 index<50%,25 cases)and high expression group(Ki-67 index≥50%,29 cases).ANOVA test(Normal distribution)or Kruskal Wallis H test(non Normal distribution)was used to compare the differences of parameters between groups.Spearman correlation analysis was used to analyze the correlation between parameters and Ki-67 expression.Receiver operating characteristic was used to analyze the diagnostic efficiency of parameters.Results Except for D^(*),the ADC,D,and f values in the low expression group are higher than those in the high expression group(P<0.05);ADC,D,and f are negatively correlated with the expression of Ki-67 and D has the highest correlation with Ki-67.The AUC values of ADC,D,and f are 0.919,0.923,and 0.884,respectively.The thresholds are 12.00,10.60,and 2.93 respectively.The sensitivity are 91.67%,95.83%,and 87.50%respectively.The specificity are 83.33%,87.50%,and 81.82%respectively.Conclusion Except for D*value,ADC,D,and f values are negatively correlated with Ki-67 expression levels in gastric cancer.Therefore,IVIM might be superior to DWI in assessing the proliferative potential of gastric cancer and provide more comprehensive information for predicting prognosis.