多b值DWI指数模型对胰腺肿瘤鉴别诊断价值初探

Differential diagnosis of pancreatic tumors:an initial study of multi b-value DWI exponential model

目的：探讨磁共振多b值Dwl指数模型对于胰腺肿瘤鉴别诊断的临床价值。方法：31例经手术病理证实的胰腺肿瘤（17例胰腺癌、8例黏液囊腺瘤、6例实性假乳头状瘤）患者及30例健康志愿者分别行常规MR扫描及多b值DwI检查，取0～1000s／mm。的12个b值。测量比较其ADcstandard，单指数模型（ADcslow—mono，ADcfast—mono）和双指数模型（ADcsloⅥrhi，ADCfast-bi）的值，并分析病变信号变化特点。结果：ADcstandard值由高到低分别为胰腺黏液囊腺瘤、正常胰腺、胰腺癌和实性假乳头状瘤。单因素方差分析显示，不同组织的ADCstandard、ADCfast—mono及ADCs—lowbi具有统计学差异（F=32．961，P=0．000；F=5．56，P=0．002；F=15．986，P=0．00）；LSD两两检验显示，肿瘤及正常胰腺的ADcstandard、ADCfast—mono和ADcslowi值之间差异具有统计学意义（P〈o．05）。胰腺癌ADcstandard较正常胰腺降低显著（P=0．000）；囊性黏液瘤ADcstandard、ADcslo＂bi和ADcfasthi值较正常胰腺明显升高（P=0．000，P=0．000，P=0．033）；实性假乳头状瘤以ADCstandard和ADCfast—mono降低为著（P=0．001，P=0．000）。结论：多b值DwI的指数模型对胰腺肿瘤的鉴别诊断能提供更多信息，有助于胰腺肿瘤的临床诊断。

Objective：To investigate and evaluate the utility of exponential model multi b-value diffusion weighted imaging （DWI） in differential diagnosis of pancreatic tumors. Methods：Thirty-one patients （17 pancreatic cancers, 8 mucous cystadenomas,and 6 solid pseudopapillary tumors） with pancreatic tumors and thirty healthy volunteers were included in this study. All the tumor cases were proved by surgery or pathology. Routine MR and multi b-value DWI （ranged 0 1000s/mm2 , 12 b-values） were performed in all cases at a 3T MR scanner （GE Healthcare 750 Discovery,USA）. ADCstan dard,monoexponential mode （ADCslow-mono,ADCfast-mono） and biexponential model （ADCslow-bi, ADCfast-bi） values were evaluated and compared respectively. Results： ADCstandard values were highest in mucous cystadenoma, which were followed by normal pancreas, pancreatic cancer and solid pseudopapillary tumor. Different ADCstandard, ADCfast-mono and ADCslow-bi values were observed in different types of pancreatic tiusses （ANOVA） （F= 32. 961, P= 0. 000;F= 5.56, P = 0. 002;F= 15. 986,P= 0. 000）. Significant differences were found in ADCstandard, ADCfast-mono and ADCslow-bi values between pancreatic tumors and normal pancreas （LSD test,P=0.05）. ADCstandard values in pancreatic cancer were lower than those of normal pancreas （P=0. 000）. ADCstandard, ADCslow-bi and ADCfast-bi values in mucous cystadenoma were higher than those of normal pancreas （P = 0. 000, P = 0. 000, P = 0. 033）, while ADCstandard and ADCfast-mono values in solid pseudopapillary tumors decreased significantly （P= 0. 001, P= 0. 000）. Conclusion： Multi b-value DWI exponential model can provide more information for differential diagnosis in pancreatic tumors, and it can help to the diagnosis of pan- creatic neoplasms.