DWI鉴别自身免疫性胰腺炎与胰腺癌的价值

The Clinical Value of Diffusion Weighted Imaging in Distinguishing Autoimmune Pancreatitis from Pancreatic Cancer

目的探讨扩散加权成像(DWI)鉴别自身免疫性胰腺炎(AIP)与胰腺癌(PAC)的应用价值及对AIP患者疗效的评估。方法 9例AIP患者、10例PAC患者以及同期10名正常胰腺(NP)对照组均行DWI扫描,其中2例AIP于治疗后复查DWI,比较AIP与PAC及AIP治疗前后的DWI表现(包括病灶的大小、形态、累及范围);比较AIP组、PAC组及NP组表观扩散系数(ADC)值并绘制ADC值鉴别AIP与PAC的受试者工作特征(ROC)曲线。结果 AIP组与PAC组在DWI上均呈高信号,AIP组高信号区以弥漫性为主(6/9),形态主要呈"腊肠"样(8/9);PAC组以局灶性为主(9/10),形态主要呈肿块型(9/10),两者差异有统计学意义(P<0.05)。AIP组ADC值[(0.944±0.096)×10-3mm2/s]明显低于PAC[(1.333±0.186)×10-3mm2/s]组及NP组[(1.372±0.195)×10-3mm2/s](P值均<0.001);PAC与NP组间差异无统计学意义(P=0.872>0.05)。ADC鉴别AIP与PAC临界值为1.051×10-3mm2/s,ROC曲线下面积为0.978。2例AIP经激素治疗后复查DWI示胰腺体积缩小,信号减低,ADC值升高。结论 DWI有助于AIP与PAC的鉴别诊断,并可作为AIP患者疗效评估的方法之一。

Objective To investigate the clinical value of diffusion-weighted imaging （DWI） in differentiating autoim- mune pancreatitis （AIP） from pancreatic cancer （PAC） and in evaluating the effect of steroid therapy for AIP patients. Methods A total of 9 patients with AIP （AIP group）, 10 patients with PAC （PAC group）, and 10 subjects without pan- creatic disease （ control group） were included in this study. DWI scanning was performed in all examinees. Two of AIP pa- tients received DWI examination again after steroid therapy. The DWI findings, including the size, shape and extent of the lesions in AIP group and PAC group, were determined. The apparent diffusion coefficient （ADC） was compared among the three groups. The ROC curve of ADC values was drawn to distinguish AIP from PAC. Results On DWI, the lesions of AIP and PAC group were characterized by high-intensity signal. In AIP group the signal area was diffusely distributed （6/ 9）, taking the form like ＂sausage＂ shape （8/9） ; while in PAC group the signal area was mainly localized （9/10） with mass-like shape （9/10） ; the differences between the two groups were statistically significant （P 〈 0.05 ）. ADC value of AIP group was （0. 944 ± 0. 096） × 10 ^- 3 mmZ/s, which was obviously lower than that of PAC group [ （ 1. 333 ± 0.186） × 10^-3mmZ/s] and that of the control group [ （1. 372 ±0. 195） × 10^-3mm^2/s], and the differences were statistically signifi- cant （P 〈 0. 001 ） ; but the difference between PAC group and the control group was not significant （P = 0. 872 〉 0. 05 ）. Receiver operating characteristic analysis indicated that the optimal ADC cutoff value was 1. 051 × 10^-3 mm2/s in distin- guishing AIP from PAC. After steroid therapy, the size of pancreatic lesions was reduced, the signals on DWI were marked- ly weakened, and the ADC values were increased. Conclusion DWI is helpful in differentiating AIP from PAC, and it can be used to evaluate the effect of steroid therapy in AIP.