目的 分析比较自由呼吸脂肪抑制磁共振弥散加权成像（diffusion-weighted imaging,DWI）在自身免疫性胰腺炎（autoimmune pancreatitis, AIP）和胰腺癌的鉴别诊断价值。方法 回顾性分析经病理证实的15例AIP与30例胰腺癌病人。术前行3.0T MRI T1WI、T2WI、MRCP、DWI。DWI序列均基于SE-EPI序列,b值为0和600 s/mm2。DWI采取自由呼吸和脂肪抑制的弥散信号采集模式,获取AIP组和胰腺癌组表观弥散系数（apparent diffusion coefficient, ADC）。结果 两组病人性别、病变部位、上腹部隐痛和黄疸例数差异均无统计学意义（P>0.05）。自由呼吸的弥散信号采集模式图像均为高信号。DWI图像优良率为95.5%。AIP组ADC为(0.001 58±0.000 21) mm2/s,胰腺癌组为（0.001 87±0.000 29） mm2/s,差异有统计学意义（P=0.001 6）。结论 自由呼吸脂肪抑制DWI有助于AIP与胰腺癌鉴别诊断。
Objective To investigate diffusion-weighted magnetic resonance imaging (DWI) using free-breathing with fat suppression acquisitions for the differential diagnosis of autoimmune pancreatitis (AIP) from pancreatic cancer. Methods The retrospective study was performed with both 15 cases of AIP and 30 cases of pancreatic cancer diagnosed by pathology. All patients underwent T1WI, T2WI, MRCP and DWI preoperatively on 3.0T MR imaging. Based on SE-EPI sequence using b values of 0 and 600 s/mm2, DWI sequences using free-breathing with fat suppression acquisitions were done. Apparent diffusion coefficient (ADC) value was obtained for the patients in AIP group and pancreatic cancer group. Results There was no statistical difference in sex, locus of lesion, upper abdomen pain, and jaundice of patients between 2 groups (P>; 0.05). Both AIP and pancreatic cancer displayed high signal intensity on images of DWI sequences using free-breathing acquisitions. DWI excellent rate was 95.5%. ADC value of AIP and pancreatic cancer was (0.001 58± 0.000 21) mm2/s and (0.001 87± 0.000 29) mm2/s respectively, with statistical difference between 2 groups (P=0.001 6). Conclusion DWI using free-breathing with fat suppression acquisitions may be helpful in differential diagnosis of AIP from pancreatic cancer.
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