酰胺质子转移成像与动态对比增强MRI评估宫颈癌神经侵犯的价值

The value of amide proton transfer weighted combined with dynamic contrast-enhanced MRI in evaluating cervical cancer nerve invasion

目的探讨酰胺质子转移加权(amide proton transfer weighted,APTw)与动态对比增强磁共振成像(dynamic contrast enhanced MRI,DCE-MRI)序列评估宫颈癌神经周围侵犯(perineural invasion,PNI)的价值。材料与方法回顾性分析36例行盆腔3.0 T MRI检查(包括APTw、DCE-MRI序列)且手术病理证实为宫颈癌的患者病例及影像资料,其中有PNI(PNI组)12例,无PNI(NPNI组)24例。由两位观察者分别测量病灶的APT值与DCE-MRI定量参数值,包括容积转移分数(volume transfer constant,K^(trans))、速率常数(exchange rate between EES and blood plasma,K_(ep))、血管外细胞外间隙容积分数(extravascular volume fraction,V_(e))以及血浆容积分数(capillary plasma volume,V_(p))。采用组内相关系数(intra-class correlation coefficient,ICC)检验2位观察者对各参数值测量结果的一致性;采用Kolmogorov-Smirov检验数据是否符合正态分布,通过两独立样本t检验或Mann-Whitney U检验比较两组间参数值的差异,采用受试者工作特征(receiver Operating Characteristic,ROC)曲线评估有差异参数诊断PNI效能,获得相应的曲线下面积(area under the curve,AUC)、阈值、敏感度和特异度。采用二元logistic回归计算有差异参数的联合诊断效能,DeLong检验进行各参数和联合参数AUC比较,Spearman相关分析检测APT值和有差异DCE-MRI参数间的相关性。结果两位观察者测得的APT值及K^(trans)值、K_(ep)值、V_(e)值、V_(p)值结果一致性良好,ICC均>0.75。两组间的APT值和V_(p)值差异有统计学意义(P<0.05),K^(trans)、K_(ep)、V_(e)差异无统计学意义(P>0.05)。PNI组的APT值(2.89%±0.72%)和V_(p)值[7.80×10^(-3)(6.80×10^(-3),1.14×10^(-2))]均大于NPNI组[APT值2.31%±0.71%;V_(p)值4.19×10^(-3)(2.04×10^(-3),7.35×10^(-3))]。评估宫颈癌PNI时,APT值和V_(p)值的AUC分别为0.717、0.785,阈值分别为2.7%及6.46×10^(-3),敏感度及特异度分别为66.7%及75.0%、83.3%及75.0%;APT值联合V_(p)值后的AUC为0.792,APT值、V_(p)值与两者联合后的AUC之间差异无统计学意义(P>0.05)。APT值与V_(p)值无相关性(r=0.219,P=0.198)。结论APTw序列及DCE-MRI的定量参数均能有效预测宫颈癌PNI,具有一定临床应用价值。

Objective:To explore the value of amide proton transfer weighted(APTw)combined with dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)sequence in evaluating perineural invasion(PNI)of cervical cancer.Materials and Methods:A retrospective analysis was conducted on 36 patients who underwent pelvic 3.0 T MRI examination(including APTw and DCE-MRI sequences)and were confirmed to have cervical cancer by surgical pathology.Among them,there were 12 cases in the PNI group and 24 cases in the non-PNI(NPNI)group.Two observers measured the APT value and DCE-MRI quantitative parameter values of the lesion,including volume transfer constant(K^(trans)),exchange rate between EES and blood plasma(K_(ep)),extravascular volume fraction(V_(e)),and capillary plasma volume(V_(p)).The mean of the measurements was then taken for statistical analysis.Using intra-class correlation coefficient(ICC)to test the consistency of the measurement results of two observers for each parameter value;Kolmogorov-Smirov test was used to determine whether the data conforms to a normal distribution.Two independent sample t-tests or Mann-Whitney U-tests were used to compare the differences in parameter values between the two groups.Receiver operating characteristic(ROC)curve was used to evaluate the diagnostic efficacy of the parameters with differences,and the corresponding area under the curve(AUC),threshold,sensitivity,and specificity were obtained.Calculate the joint diagnostic efficacy of differential parameters using binary logistic regression,and compare the AUC of each parameter and the joint parameter using DeLong test.Use Spearman correlation to detect the correlation between APT values and differential DCE-MRI parameters.Results:The APT values,K^(trans)values,K_(ep)values,V_(e)values,and V_(p)values measured by the two observers showed good consistency,with ICC values greater than 0.75.The difference in APT and V_(p)values between the two groups was statistically significant(P<0.05),while the difference in K^(trans),K_(ep),and V_(e)was not statistically significant(P>0.05).The APT value(2.89%±0.72%)and V_(p)value[7.80×10^(-3)(6.80×10^(-3),1.14×10^(-2))]of the PNI group were both higher than those of the NPNI group[APT value 2.31%±0.71%;V_(p)value 4.19×10^(-3)(2.04×10^(-3),7.35×10^(-3))].The AUC for evaluating the APT value and V_(p)value of cervical cancer PNI were 0.717 and 0.785,respectively;the thresholds are 2.7%and 6.46×10^(-3),respectively,and the sensitivity and specificity are 66.7%and 75.0%,83.3%and 75.0%,respectively.The AUC of APT value combined with V_(p)value is 0.792;there was no statistically significant difference(P>0.05)between the APT value,V_(p)value,and the AUC of the combined evaluation of PNI.There is no correlation between APT value and V_(p)value(r=0.219,P=0.198).Conclusions:The quantitative parameters of APTw sequence and DCE-MRI can effectively predict cervical cancer PNI,which has certain clinical application value.