CT动态容积灌注成像检出早期胃癌并评估其病理分型

Dynamic volume perfusion CT imaging for detecting and evaluating pathological type of early gastric cancer

目的 观察CT动态容积灌注(DVPCT)成像检出早期胃癌并鉴别其病理分型的价值。方法 回顾性分析127例经病理证实的早期胃癌患者,根据术前检查方式分为增强CT组(n=67)或DVPCT组(n=60);比较组间一般资料、CT资料,以及DVPCT组内胃印戒细胞癌(SRCC)与胃腺癌的强化程度、门静脉期与延迟期峰值期相及峰值时间;绘制受试者工作特征(ROC)曲线,计算曲线下面积,评估DVPCT时间-密度曲线(TDC)鉴别早期SRCC与腺癌的效能。结果 DVPCT组肿瘤检出率、剂量长度乘积及有效剂量均高于增强CT组(P均<0.05);2组患者年龄、性别、病理分型、肿瘤位置及肿瘤最大径差异均无统计学意义(P均>0.05)。52例(52/60,86.67%)经DVPCT检出早期胃癌的患者中,SRCC 12例、腺癌39例、黏液腺癌1例;其中,早期胃SRCC与早期胃腺癌患者肿瘤强化程度、门静脉期及延迟期峰值期相及峰值时间差异均有统计学意义(P均<0.05)。以峰值时间37.3 s为最佳截断值,DVPCT TDC鉴别早期胃SRCC与早期胃腺癌的敏感度、特异度、阳性预测值、阴性预测值、准确率及曲线下面积分别为83.33%、84.62%、62.50%、94.29%、84.31%及0.895。结论 DVPCT检出早期胃癌效果优于常规增强CT;TDC可有效鉴别早期胃SRCC与早期胃腺癌。

Objective To observe the value of dynamic volume perfusion CT(DVPCT)imaging for detecting and evaluating pathological type of early gastric cancer.Methods Data of 127 patients with early gastric cancer confirmed by pathology were retrospectively analyzed.The patients were divided into enhanced CT group(n=67)and DVPCT group(n=60)according to preoperative examination methods.Clinical and CT data were compared between groups,and tumor enhancement,peak phase and peak time in both portal vein phase and venous phase were compared between patients with early gastric signet ring cell carcinoma(SRCC)and early gastric adenocarcinoma in DVPCT group.Then receiver operating characteristic(ROC)curves were drawn,the areas under the curves(AUC)were calculated to evaluate the efficacy of time-density curve(TDC)of DVPCT images for differentiating early SRCC and early adenocarcinoma.Results The detection rate of tumor,dose-length product and effective dose in DVPCT group were all higher than those in enhanced CT group(all P<0.05).No significant difference of patients'age,gender,pathological type,tumor location nor the maximum tumor size was found between groups(all P>0.05).Among 52 patients(52/60,86.67%)with early gastric cancer detected with DVPCT,12 cases were found with SRCC,39 cases with adenocarcinomas and 1 case with mucinous adenocarcinoma.Significant difference of tumor enhancement,peak phase and peak time in both portal vein phase and venous phase were found between patients with SRCC or adenocarcinoma.Taken 37.3 s as the optimal cut-off value of peak time,the sensitivity,specificity,positive predictive value,negative predictive value,accuracy and AUC was 83.33%,84.62%,62.50%,94.29%,84.31%and 0.895,respectively.Conclusion DVPCT had better detecting ability for early gastric cancer than conventional enhanced CT,which could be used to effectively differentiating early gastric SRCC and early gastric adenocarcinoma according to TCD.