体素内不相干运动扩散加权成像评价胰腺纤维化的初步研究

Intravoxel incoherent motion diffusion weighted imaging for the evaluation of pancreatic fibrosis: a preliminary study

目的:探讨磁共振体素内不相干运动扩散加权成像(IVIM-DWI)在胰腺纤维化评价中的价值。方法 :收集15例健康志愿者(对照组)及45例胰头体部或壶腹部病变并行胰十二指肠切除术的患者(病变组),病变组术前一周内均行3.0T IVIM-DWI检查及术后胰腺断端纤维化分期评价(F0期15例,F1期10例,F2期11例,F3期9例),由两名具有5年以上腹部影像诊断经验的放射科医师于胰腺断端处绘制感兴趣区(ROI),测得真实扩散系数(D),假性扩散系数(D*)及灌注分数(f)值,采用Spearman秩相关系数及受试者工作特性曲线(ROC)分析D、D*、f值与胰腺纤维化间的相关性及诊断胰腺纤维化分期的效能。结果:两名测量者间测得受试者的D、D*、f值的一致性良好(ICC:0.925、0.907、0.823)。f值与纤维化分期的相关性略高于D和D*(Spearman相关性检验:r=-0.651、-0.392、-0.523,P分别为<0.001、0.002、<0.001)。f值区分F0/(F1~F3)期、(F0,F1)/(F2,F3)的曲线下面积略高于D及D*(F0比(F1~F3):0.822、0.662、0.764;(F0,F1)比(F2,F3):0.876、0.772、0.799),但差异无统计学意义(P均大于0.05)。结论:IVIM-DWI成像是一种良好的胰腺纤维化的分期方法。

Objective： To evaluate the diagnostic performance of intravoxel incoherent motion diffusion weighted imaging （IVIM-DWI） for the evaluation of pancreatic fibrosis. Methods： A total of 15 healthy volunteers and 45 patients （F0： 15, F1： 10, F2： 11, F3： 9） with pancreatic or ampullary masses and subsequent panereaticoduodenectomy underwent preoperative 3.0T MR IVIM imaging within less than one week. IVIM-DWI parameters （true diffusion coefficient （D）, pseudo-diffusion coefficient （D＊）, and perfusion fraction （f）） were measured independently by two radiologists with more than 5 years of experience in abdominal imaging diagnosis. Spearman rank correlation coefficient was used to analyze the correlation between D, D＊, f values and pancreatic fibrosis. Receiver operating characteristic curve （ROC） analysis was to determine the diagnostic performance of IV1M parameters for staging of pancreatic fibrosis （F0-F3）. Results： The D, D＊ and f values measured by the two subjects were excellent（ICC： 0.925, 0.907, 0.823）. f values showed a better negative correlation with fibrosis stages（r=-0.651, P〈0.001） than D（r=-0.392, P=0.002） and D＊（r=-0.523, P〈0.001）. f values had higher area under the curve（AUC） than that of D and D＊ （F0 vs （F1-F3）： AUC=0.822, 0.662, 0.764, respectively; （F0,F1） vs （F2, F3）： AUC=0.876, 0.772, 0.799, respectively）, though without statistical significance（all P〉0.05）. Conclusion： IVIM-DWI is a promising method for staging of pancreatic fibrosis.