MRI联合DWI对胃间质瘤与胃癌的鉴别价值分析

Analysis of the Differential Value of MRI Combined with DWI for Gastric Stromal Tumor and Gastric Cancer

目的分析磁共振成像(MRI)联合扩散加权成像(DWI)对胃间质瘤与胃癌的鉴别价值。方法回顾性分析经手术病理证实并行MRI联合DWI检查的65例胃癌患者及21例间质瘤患者的影像资料。对比分析胃间质瘤和胃癌在MRI联合DWI检查中的影像学表现及ADC值,绘制ROC曲线分析ADC值鉴别诊断胃间质瘤与胃癌的价值,采用Kappa检验评价MRI联合DWI检查中的ADC值诊断结果与手术病理检查结果的一致性。结果86例研究对象中T_(2)WI压脂、DWI图像上均呈不同程度的高信号,虽然胃癌的图像信号强度总体上略高于胃间质瘤,但二者征象特征并不易准确区分;此外,可见胃间质瘤多发于胃体、胃底,胃癌多发于胃窦。胃癌患者ADC值为(1.05×10^(-3)±0.27×10^(-3))s/mm^(2),显著低于胃间质瘤患者ADC值[(1.43×10^(-3)±0.21×10^(-3))s/mm^(2)](t=5.891,P<0.05)。ADC值鉴别诊断胃间质瘤与胃癌的曲线下面积为0.865,约登指数为0.688,临界值为1.26×10^(-3)s/mm^(2),此时对应的敏感度为83.08%,特异性为85.71%,准确度为83.72%,误诊率为14.29%,漏诊率为16.92%,阳性预测值为94.74%,阴性预测值为62.07%。MRI联合DWI检查中的ADC值诊断结果与手术病理检查结果比较,Kappa值为0.609(P<0.05),说明一致性较高。结论MRI联合DWI检查作为一种无创的影像学检查技术,有助于鉴别诊断胃间质瘤与胃癌,具有一定的临床应用价值。

Objective To analyze the value of magnetic resonance imaging(MRI)combined with diffusion-weighted imaging(DWI)in differentiating gastric stromal tumor and gastric cancer.Methods The imaging data of 65 patients with gastric cancer and 21 patients with stromal tumor who were confirmed by surgery and pathology and underwent MRI combined with DWI examination were retrospectively analyzed.The imaging manifestations and ADC values of gastric stromal tumor and gastric cancer in MRI combined with DWI were compared and analyzed,ROC curve was drawn to analyze the value of ADC value in differential diagnosis of gastric stromal tumor and gastric cancer,Kappa test was used to evaluate the consistency between the diagnostic results of ADC value in MRI combined with DWI examination and the results of surgical and pathological examinations.Results Among the 86 subjects,T_(2)WI fat suppression and DWI images showed different degrees of high signal,and although the image signal intensity of gastric cancer was slightly higher than that of gastric stromal tumor,the signs and characteristics of the two were not easy to distinguish accurately;in addition,it could be seen that gastric stromal tumors were mostly located in the body and fundus of the stomach,and gastric cancers were mostly located in the gastric antrum.The ADC value of gastric cancer patients was(1.05×10^(-3)±0.27×10^(-3))s/mm^(2),which was obviously lower than the ADC value of gastric stromal tumor patients[(1.43×10^(-3)±0.21×10^(-3))s/mm^(2)](t=5.891,P<0.05).The area under the curve of ADC value in the differential diagnosis of gastric stromal tumor and gastric cancer was 0.865,Youden index was 0.688,and the critical value was 1.26×10^(-3)s/mm^(2),the corresponding sensitivity was 83.08%,specificity was 85.71%,the accuracy was 83.72%,the misdiagnosis rate was 14.29%,the missed diagnosis rate was 16.92%,the positive predictive value was 94.74%,and the negative predictive value was 62.07%.When ADC value of MRI combined with DWI examination was compared with the results of surgical and pathological examination,the Kappa value was 0.609(P<0.05),indicated a high consistency.Conclusion MRI combined with DWI examination,as a non-invasive imaging technique,is helpful for the differential diagnosis of gastric stromal tumor and gastric cancer,and has certain clinical application value.