摘要目的 探讨3.0T磁共振扩散加权成像(DWI)信号强度诊断胰腺导管腺癌的价值.方法 回顾性分析病理证实的70名胰腺导管腺癌患者及18名胰腺正常志愿者3.0T上腹部相同扫描参数DWI(b值为0,600 s/mm2)资料,测量胰腺癌和正常胰腺的DWI信号强度(SIb0,SIb600)及表观扩散系数(ADC)值.计算测得的胰腺导管腺癌及正常胰腺SIb0、SIb600、ADC值的一致性系数(ICC).胰腺癌与正常胰腺平均SIb0、SIh600和ADC值差异采用独立样本非参数Mann-Whitney U检验,SIb0、SIb600和ADC值诊断胰腺导管腺癌的效能采用受试者工作特征曲线下面积(AUC)判断.结果 两位医师测得的胰腺导管腺癌和正常胰腺的SIb0、SIb600及ADC值的一致性均为优秀(ICC分别为0.977、0.983、0.961和0.969、0.979、0.973).胰腺癌和正常胰腺的平均SIb0、SIh600及ADC值分别为1165.7±273.4、503.6±119.8、(1.40 ±0.20)×10-3mm2/s和650.9±104.5、263.7±49.1、(1.53±0.21)×10-3 mm2/s,两组间各参数的差异均具有统计学意义(P值均＜0.05).以正常胰腺SIb0、SIb600及ADC值为对照,诊断胰腺癌的AUC分别为0.987、0.980、0.697.SI诊断胰腺导管腺癌的价值显著高于ADC(P值均＜0.01).以正常胰腺SIb600为参考,SIb600≤324.4作为诊断胰腺癌临界值的敏感性和特异性分别为95.7％和94.4％.结论 3.0T DWI信号强度较ADC值对胰腺癌有更好的诊断价值,SI作为定量影像生物标记在临床应用中应当予以重视.

abstractsObjective To investigate the value of signal intensity (SI) of diffusion weighted imaging (DWI) at 3.0 T magnetic resonance in the diagnosis of pancreatic adenocarcinoma.Methods Seventy patients with histologically confirmed pancreatic ductal adenocarcinoma and 18 healthy volunteers underwent DWI at 3.0 T (b =0, 600 s/mm2).The SIb0, SIb600 and apparent diffusion coefficient (ADC) values of normal pancreas as well as the pancreatic adenocarcinomas were measured by two independent observers.The inter-observer variability for SIb0, SIl00 and ADC values was analyzed by using interclass correlation coefficient (ICC).The SIb0, SIb600 and ADC values between the tumors and normal pancreatic tissues were analyzed and compared by using Mann-Whitney U test, and receiver-operating characteristic (ROC) analyses were used to determine the diagnostic performances of the three parameters to distinguish pancreatic adenocarcinoma from normal pancreas.Results All the SIb0, SIb600 and ADC indicated excellent inter-observer variability.ICC values for ADC, SIb0, SIb600 of pancreatic adenocarcinoma were 0.977, 0.983, 0.961, and ICC values of normal pancreas were 0.969, 0.979, 0.973.The mean SIb0, SIb600 and ADC values were 1165.7 ± 273.4,503.6 ± 119.8, (1.40 ± 0.20) × 10-3 mm2/s in pancreatic adenocarcinoma, and 650.9 ± 104.5,263.7 ± 49.1, (1.53 ± 0.21) × 10-3 mm2/s in normal pancreas, and the difference between the two groups was statistically significant (P ＜0.01).With the SIb0 、SIb600 and ADC values of normal pancreas as a reference,the area under ROC curve (AUC) were 0.987, 0.980 and 0.697, respectively.SI was significantly better than ADC for diagnosis of pancreatic adenocarcinoma (P＜0.01).With the SIb600 of normal pancreas as a reference, SIb600 ≤324.4 as the cutoff value for diagnosis of pancreatic adenocarcinoma, the sensitivity and specificity were 95.7％ and 94.4％.Conclusions SI of DWI at 3.0 T has a better diagnostic accuracy in the diagnosis of pancreatic ductal adenocarcinoma than ADC.As a quantitative imaging bio-marker in clinical practice, SI should be valued.