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

YUAN Letian; WANG Yilin; GUO Wenxiu; LIN Xiangtao

Abstract：Objective To investigate correlation between intravoxel incoherent motion(IVIM)parameters and Ki-67 expres-sion 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 pa-tient were measured and calculated including ADC,pure water diffusion coefficient(D),perfusion fraction(f),and pseudo dif-fusion coefficient(D*).Simultaneously,the expression value of Ki-67 immunohistochemistry was obtained in gastric cancer.Ac-cording 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 specific-ity are 83.33%,87.50%,and 81.82%respectively.Conclusion Except for D* value,ADC,D,and f values are negatively cor-related with Ki-67 expression levels in gastric cancer.Therefore,IVIM might be superior to DWI in assessing the proliferative po-tential of gastric cancer and provide more comprehensive information for predicting prognosis.