拉伸指数与单指数模型多b值DWI定量参数在胰腺癌的对照研究  

The Application Value of Quantitative Parameters Derived from Monoexponential and Stretched-Exponential Models Multiple B Values Diffusion Weighted Imaging in Pancreatic Cancer

作　　者：马婉玲 魏梦绮 任静 张劲松 潘奇 侯炜寰 张广文 文娣娣 仲津漫 宦怡 

机构地区：[1]空军军医大学西京医院放射科,西安710032

出　　处：《临床放射学杂志》2017年第12期1793-1797,共5页Journal of Clinical Radiology

基　　金：国家自然科学基金重大国际(地区)合作与交流项目(编号:81220108011);国家自然科学基金青年面上连续项目(编号:81370039)

摘　　要：目的探讨拉伸指数与单指数模型多b值磁共振扩散加权成像(DWI)定量参数在胰腺癌的应用价值。方法搜集临床或手术证实的37例胰腺癌患者,应用GE Discovery MR750 3.0T磁共振扫描仪对所有患者行胰腺多b值DWI。应用MADC软件的单指数和拉伸指数模型分析多b值DWI,得到标准化表观扩散系数(ADC_(standard))、分布扩散系数(DDC)和扩散异质性指数(α)参数图,测量胰腺癌和癌周胰腺组织的ADC_(standard)、DDC和α值,并应用独立样本t检验进行统计学分析。结果胰腺癌的DDC值明显低于癌周胰腺组织的DDC值(1.244×10^(-3)mm^2/s vs.1.679×10^(-3)mm^2/s,P=0.013),胰腺癌的α值明显高于癌周胰腺组织的α值(0.720 vs.0.653,P=0.019),差异均有统计学意义。DDC和α值鉴别胰腺癌和癌周胰腺组织的受试者工作特征曲线(ROC)曲线下面积分别为0.640、0.631。胰腺癌的DDC值和ADC_(standard)值显著正相关(r=0.401,P=0.013);α值和ADC_(standard)值显著正相关(r=0.360,P=0.026)。结论拉伸指数模型DWI相关参数DDC和α可以鉴别胰腺癌和癌周胰腺组织,DDC鉴别胰腺癌和癌周胰腺组织时较α的诊断效能更高。Objective To explore the application value of quantitative parameters derived from monoexponential and stretched-exponential models（ SEM） multiple b values diffusion weighted imaging in distinguishing pancreatic cancer from non-tumorous pancreas. Methods Subjects comprised 37 pancreatic cancers confirmed by clinical data or surgery. Pancreas multiple b values DWI were performed using GE Discovery MR750 3. 0 T scanner. Standard apparent diffusion coefficient（ ADC_（standard）） was calculated using monoexponential diffusion model. Distributed diffusion coefficient（ DDC） and diffusion heterogeneity index（ α） were calculated using SEM diffusion model. ADC_（standard）,DDC and α value of pancreatic cancers and non-tumorous pancreas were compared using Independent Samples t-Test. P values 0. 05 were considered significant. Results Mean DDC value of pancreatic cancer was significantly lower than that of non-tumorous pancreas（ 1. 244 vs. 1. 679 × 10^（-3） mm^2/s,P = 0. 013）. Mean α value of pancreatic cancer was significantly higher than that of nontumorous pancreas（ 0. 720 vs. 0. 653,P = 0. 019）. Areas under the curve（ AUC） for DDC and α were 0. 640 and 0. 631 respectively. The diagnostic performance of DDC in differentiating pancreatic cancer from non-tumorous pancreas was higher than α. DDC of pancreatic cancer was positively correlated to ADC_（standard）（ r = 0. 401,P = 0. 013）. α of pancreatic cancer was positively correlated to ADC_（standard）（ r = 0. 360,P = 0. 026）. Conclusion DDC and α derived from SEM DWI model can distinguish pancreatic cancer from non-tumorous pancreas. DDC is the better parameter than α for differentiating pancreatic cancer from non-tumorous pancreas.

关 键 词：胰腺癌 拉伸指数模型 扩散加权成像 标准化表观扩散系数 分布扩散系数 扩散异质性指数 

分 类 号：R445.2[医药卫生—影像医学与核医学] R735.9[医药卫生—诊断学]