动态对比增强MRI放射状采集容积内插屏气序列(Radial-VIBE)定量参数预测膀胱癌病理学分级

目的 评价动态对比增强MRI（DCE-MRI）放射状采集容积内插屏气检查（Radial-VIBE）序列定量参数预测膀胱癌病理学分级的价值。方法 前瞻性纳入60例经术后病理证实为膀胱尿路上皮癌的膀胱癌患者，将其分为低级别组（n=36）和高级别组（n=24）。比较组间DCE-MRI参数，包括容积转运常数（K^trans）、速率常数（K_ep）、血管外细胞外间隙容积（V_e）及对比剂浓度-时间曲线下初始面积（IAUC）的差异；采用组内相关系数（ICC）评价观察者间测量结果的一致性。采用Spearman秩相关分析评价各参数与膀胱癌病理分级的相关性。绘制受试者工作特征（ROC）曲线，计算曲线下面积（AUC），评价各参数预测高级别膀胱癌的效能。结果 观察者间测量定量参数K^trans、K_ep、V_e及IAUC结果的一致性良好（ICC=0.82、0.83、0.83、0.85，P均<0.05）。高级别组K^trans、K_ep及IAUC均显著高于低级别组（P均<0.05），V_e显著低于低级别组（P<0.05）。K^trans、K_ep及IAUC均与病理分级呈正相关（r=0.61、0.54、0.29，P均<0.05），V_e与病理分级呈负相关（r=-0.36，P<0.05）。K^trans、K_ep及IAUC预测高级别尿路上皮癌的AUC分别为0.86、0.82及0.67。结论 DCE-MRI Radial-VIBE序列定量参数K^trans、K_ep、Ve及IAUC可辅助预测膀胱癌病理学分级。

Dynamic contrast enhanced MRI quantitative parameters of radial acquisition of volumetric interpolated breath-hold examination (Radial-VIBE) sequences for predicting pathological grade of bladder cancered

Objective To observe the value of radial acquisition of volumetric interpolated breath-hold examination (Radial-VIBE) sequences on dynamic contrast enhanced MRI (DCE-MRI) in predicting the pathological grade of bladder cancer. Methods Sixty patients with bladder urothelial carcinoma confirmed by postoperative pathology were enrolled and divided into low grade group (n=36) and high grade group (n=24). DCE-MRI parameters, including volume transfer constant (K^trans), rate constant (K_ep), extracellular volume fraction (V_e), and initial area under the curve (IAUC) of contrast concentration-time, were compared between groups. Intra-class correlation coefficient (ICC) was used to evaluate the interobserver consistency of the measurement results of the above parameters. Spearman rank correlation analysis was used to evaluate the correlations of each parameter and pathological grade of bladder cancer. The receiver operating characteristic (ROC) curve was plotted and the area under the curve (AUC) was calculated to evaluate the efficacy of each parameter for predicting high grade urothelial carcinoma. Results The quantitative parameters K^trans, K_ep, V_e and IAUC showed good interobserver consistency (ICC=0.82, 0.83, 0.83, 0.85, all P<0.05). K^trans, K_ep and IAUC in high grade group were significantly higher than those in low grade group (all P<0.05), and V_e was significantly lower than that in low grade group (P<0.05). K^trans, K_ep and IAUC were positively correlated with pathological grade (r=0.61, 0.54, 0.29, all P<0.05), while V_e was negatively correlated with pathological grade (r=-0.36, P<0.05). K^trans, K_ep and IAUC had high predictive efficiency for high grade urothelial carcinoma (AUC=0.86, 0.82, 0.67). Conclusion DCE-MRI quantitative parameters of Radial-VIBE sequences, including K^trans, K_ep, V_e and IAUC could assist in predicting pathological grade of bladder cancer.