目的探究磁共振扩散加权成像 (DWI)表观扩散系数(ADC)与胰腺导管腺 癌分化程度之间的关系。方法 回顾性 分析术后病理证实的75名胰腺导管腺癌 患者(男性39名，女性36名，年龄36-76 岁；中分化55名，低分化20名)及胰腺正 常志愿者49名(男性29名，女性20名，年 龄21-62岁)DWI(b值为0，600s/mm2 )，计 算及测量正常胰腺头、体及尾部ADC和胰 腺癌实性组织ADC。采用独立样本非参数 Mann-Whitney U检验比较胰腺癌组与正 常胰腺组ADC、胰腺癌中分化与低分化组 ADC差异。ROC分析ADC诊断胰腺癌效能。 结果 胰腺癌平均ADC(1.36±0.14)×10- 3 m m 2 /s，与正常胰腺头、体及尾部 ADC(分别为1.66±0.34、1.77±0.36、 1.62±0.38×10-3mm2 /s)差异皆具有统计 学意义(P值皆=0.000)。胰腺癌中分化 组与低分化组ADC(分别为1.36±0.14和 1.35±0.13×10-3mm2 /s)差异不具有统计 学意义(P=0.657)。以正常胰腺平均ADC 为参考，ROC分析胰腺癌ADC曲线下面积 为0.863，95%可信区间为79.5%-93.1%， ADC≤1.492×10-3mm2 /s作为诊断胰腺癌的 临界值，敏感度和特异度分别为75.5%和 85.3%。 结论 DWI对胰腺导管腺癌有较好 的诊断价值；ADC值不能用于预测胰腺导 管腺癌分化程度。

Objective To evaluate the clinical usefulness of diffusion-weighted magnetic resonance imaging (DWI) in patients with pancreatic cancer by comparing the apparent diffusion coefficient (ADC) value with tumor differentiation. Methods 75 patients (39 Males, 26 Females; age range 36-76 years) with histologically confirmed pancreatic ductal adenocarcinoma (55 with moderately differentiated tumors and 20 with poorly differentiated tumors) and 49 healthy volunteers (29 Males, 20 Females; age range 21-62 years) underwent respiratory triggered DWI at 3.0 T before surgery. Apparent diffusion coefficient (ADC) values of normal pancreas head, body and tail as well as ADC values of the pancreatic adenocarcinomas were calculated and measured. The ADC values of normal pancreas and tumors were statistically analyzed and compared using Mann-Whitney U test. Comparison of two data sets of the tumor differentiation was also performed using Mann-Whitney U test. ROC curve was used to analyze the diagnostic power of ADC value. Results Mann-Whitney U tests showed ADC values differed significantly between pancreatic adenocarcinoma group [(1.36±0.14)×10-3mm2 /s] and normal pancreas head, body or tail groups[(1.66±0.34), (1.77±0.36), (1.62±0.38)×10-3mm2 / s, respectively] (all of the P=0.000). However, no association between ADC values of pancreatic adenocarcinoma and tumor differentiation was observed. With the global ADC values of normal pancreas as a reference, the area under the curve and the 95% confidence interval of ROC analysis were 0.863 and 79.5%-93.1%, respectively. The sensitivity and specificity were 75.5% and 85.3%, when ADC≤1.815×10-3mm2 /s was used as the cutoff value for the differential diagnosis of pancreatic adenocarcinoma from normal pancreas. Conclusion DWI had a better diagnostic accuracy in the diagnosis of pancreatic ductal adenocarcinoma. Although ADC values are significantly different between benign pancreas and pancreatic adenocarcinoma, no associations between ADC values and tumor differentiation were observed.