2种弥散加权成像对胰腺癌和肿块型胰腺炎的鉴别

Differentiation of Pancreatic Cancer and Mass-Like Pancreatitis by Two Methods of Diffusion-Weighted Imaging

目的:分析比较呼吸门控脂肪抑制弥散加权成像(diffusion weighted imaging,DWI)与憋气DWI在胰腺癌和肿块型胰腺炎中的鉴别诊断价值。方法:回顾分析经手术病理确诊的30例胰腺癌与17例肿块型胰腺炎患者术前行3.0T磁共振DWI检查的资料。DWI基于自旋回波-回波平面成像(SE-EPI)序列,包括憋气DWI和呼吸门控脂肪抑制DWI序列,b值为600 s/mm2。分析比较胰腺癌及肿块型胰腺炎的表观弥散系数(apparent diffusion coefficient,ADC)。采用受试者工作特征(receiver operating characteristic,ROC)曲线分析比较2种DWI序列鉴别诊断胰腺癌及肿块型胰腺炎的效能。结果:在憋气DWI序列上,胰腺癌与肿块型胰腺炎ADC值差异无统计学意义(P>0.05);在呼吸门控脂肪抑制DWI序列上,胰腺癌与肿块型胰腺炎的ADC值差异有统计学意义(P<0.01)。在呼吸门控脂肪抑制DWI序列中,以ADC≥1.33×10-3 mm2/s为诊断阀值从肿块型胰腺炎中鉴别诊断胰腺癌,灵敏度和特异度分别为86.7%和88.9%,阳性预测值和阴性预测值分别为96.3%和66.7%。在憋气DWI序列中,以ADC值≥1.45×10-3 mm2/s为诊断阀值从肿块型胰腺炎中鉴别诊断胰腺癌,灵敏度和特异度分别为73.3%和88.9%,阳性预测值和阴性预测值分别为95.7%和50.0%。结论:与憋气DWI比较,呼吸门控脂肪抑制DWI序列对胰腺癌和肿块型胰腺炎的鉴别诊断价值更高。

Objective：To compare the value of respiratory-triggered diffusion-weighted imaging with fat suppression（RTIR-DWI）and common breath-hold DWI（BH-DWI）for the differential diagnosis of pancreatic cancer and mass-like pancreatitis. Methods：A total of 30 cases of pancreatic cancer and 17 cases of mass-like pancreatitis,which were confirmed by surgical pa-thology,underwent DWI at 3.0T before operation.DWI based on SE-EPI sequence,of which b value was 600 s/mm2 ,included BH-DWI and RTIR-DWI.Apparent diffusion coefficient（ADC）value of pancreatic cancer and mass-like pancreatitis were statis-tically analyzed and compared.Receiver operating characteristic（ROC）curve was used to analyze and compare the effect of two DWI sequences in the differential diagnosis of pancreatic cancer and mass-like pancreatitis.Results：On BH-DWI,ADC value did not have significant difference between pancreatic cancer and mass-like pancreatitis（P 〉0.05）.On RTIR-DWI,ADC value had significant difference between pancreatic cancer and mass-like pancreatitis（P 〈0.01）.On RTIR-DWI,the sensitivity,speci-ficity,positive predictive value and negative predictive value were 86.7%,88.9%,96.3% and 66.7%,respectively,when ADC≥1.33×10^-3 mm^2/s was used as a cutoff for the differential diagnosis of pancreatic cancer from mass-like pancreatitis.On BH-DWI,the sensitivity,specificity,positive predictive value and negative predictive value was 73.3%,88.9%,95.7% and 50.0%,respectively,when ADC≥ 1.45 × 10^-3 mm^2/s was used as a cutoff for the differential diagnosis of pancreatic cancer from mass-like pancreatitis.Conclusions：Compared to BH-DWI,RTIR-DWI may be more conducive to the diagnosis and differentiation of pancreatic cancer and mass-like pancreatitis.