不同b值磁共振扩散加权成像鉴别诊断胰腺癌与慢性肿块型胰腺炎

Different b values on DWI in differential diagnosis of pancreatic carcinoma and chronic mass-forming pancreatitis

目的分析不同b值下胰腺癌、慢性肿块型胰腺炎与正常胰腺组织ADC值及其差值(DADC值)变化情况,探讨用于鉴别胰腺癌、慢性肿块型胰腺炎的最适b值。方法对15例胰腺癌(Ⅰ组)、4例慢性肿块型胰腺炎患者(Ⅱ组)及15名胰腺正常的志愿者(Ⅲ组)行磁共振扩散加权成像(DWI),b值分别为333、667、1000s/mm2。测量各b值下癌区、慢性炎症区和正常胰腺区的ADC值,并对不同b值时三种组织ADC值及不同组织间DADC值的变化进行分析。结果相同b值时胰腺癌区ADC值低于慢性炎症肿块区和正常胰头区。不同b值时各组内ADC值差异均有统计学意义(P<0.05),随b值增大,三组的ADC值均有下降,其中胰腺癌区平均下降率最低(15.66%和5.19%)。b=333和667s/mm2时,胰腺癌区与慢性炎症肿块区、胰腺癌区与正常胰头区的ADC值差异均有统计学意义(P<0.05)。不同b值时,胰腺癌区与慢性炎症肿块区、胰腺癌区与正常胰头区两配对组组内的DADC值差异均有统计学意义(P<0.05),且b=333s/mm2时各配对组组内的DADC值最大。结论在一定范围内小b值有助于胰腺癌与慢性肿块型胰腺炎的鉴别诊断。

Objective To investigate the changes of ADC at different b values in pancreatic carcinoma,chronic mass-forming pancreatitis and normal pancreas,and to evaluate the optimal b value in differentiating diagnosis.Methods Diffusion-weighted imaging（DWI） was performed in 15 patients of pancreatic carcinoma（group Ⅰ）,4 with chronic mass-forming pancreatitis（group Ⅱ） and 15 normal volunteers（group Ⅲ） with the b value of 333,667 and 1000 s/mm^2,respectively.The ADC values of carcinous regions,inflammatory mass and normal pancreatic head were measured,and the difference of ADC（DADC） in different tissues of each patient was calculated.Results At the same b value,ADC value of carcinous regions was lower than those of inflammatory mass and normal pancreatic head.ADC values at three different b values in the same tissue were statistically different（P〈0.05）.As the b value increased,the ADC value decreased,and in carcinous regions the decreased rates of ADC value were the lowest（15.66% and 5.19%）.When b value was 333 and 667 s/mm^2,ADC values of carcinous regions were statistically different from those of the inflammatory mass and normal pancreatic head（P〈0.05）.There were statistically differences of DADC values between pancreatic carcinoma and chronic mass-forming pancreatitis,also between pancreatic carcinoma and normal pancreas detected at all three different b values（P〈0.05）.When b value was 333 s/mm^2,DADC values were significant higher than those detected at other two b values.Conclusion Smaller b value is helpful for differentiating diagnosis of pancreatic carcinoma and chronic mass-forming pancreatitis.