多期增强MRI和表观扩散系数直方图鉴别肝内胆管囊腺瘤及囊腺癌的价值

Value of multi-phase enhanced MRI combined with histogram analysis of apparent diffusion coefficient in differential diagnosis of intrahepatic biliary cystadenoma and intrahepatic biliary cystadenocarcinoma

目的探讨多期增强MRI和ADC直方图定量分析鉴别肝内胆管囊腺瘤（HBCA）和肝内胆管囊腺癌（HBCAC）的价值。 方法回顾性分析2009年1月至2016年9月复旦大学附属中山医院，经手术病理证实为肝内胆管囊腺肿瘤（HBCT）的25例患者，其中HBCA 16例，HBCAC 9例。患者均行上腹部MRI平扫和多期增强扫描，观察病灶MRI表现，计算动脉期、门静脉期和延迟期病灶最大强化率（pCER）。进行ADC直方图分析，获得ADC直方图定量参数，包括平均值，标准差，中位数，峰度系数，偏度系数，第10、30、70、90百分位数。定性指标采用Fisher精确检验比较，符合正态分布且方差齐的连续性变量采用独立样本t检验比较，偏态分布的连续性变量采用Mann-Whitney U检验比较，对HBCA和HBCAC患者间有差异的变量采用ROC评价其鉴别诊断效能。 结果HBCA和HBCAC患者的性别构成、年龄、周围胆管扩张、病灶内壁结节的差异有统计学意义（P均〈0.05），病灶最大径、囊液T1WI高信号和分隔的差异无统计学意义（P均〉0.05）。HBCAC患者动脉期、门静脉期和延迟期的pCER均高于HBCA患者，差异均有统计学意义（P均〈0.05）。HBCAC患者的ADC值的标准差高于HBCA患者，峰度系数及第10百分位数低于HBCA患者，差异有统计学意义（P均〈0.05）；两组间的平均值，中位数，偏度系数，第30、70和90百分位数差异均无统计学意义（P均〉0.05）。当ADC直方图第10百分位数值≤2.060×10-3 mm2/s时，鉴别HBCA及HBCAC的ROC曲线下面积最大（0.861），诊断准确度、敏感度、特异度分别为84.0%、77.8%和87.5%。 结论多期增强MRI和ADC直方图定量分析对HBCA及HBCAC的鉴别诊断有一定的价值，且以ADC直方图第10百分位数值诊断效能最高。

ObjectiveTo investigate the value of quantitative multi-phase enhanced MRI combined with histogram analysis of ADC in differential diagnosis of intrahepatic biliary cystadenoma （HBCA） and intrahepatic biliary cystadeno carcinoma （HBCAC）. MethodsTwenty-five patients with pathologically confirmed intrahepatic biliary cystic tumor （HBCT）, including 16 cases of HBCA and 9 cases of HBCAC, were retrospectively analyzed. All the patients underwent upper abdominal MR plain scan and multi-phase enhanced scan. The MRI findings of the lesions were observed. The peak contrast enhancement ratio （pCER） of the lesions in the arterial phase, portal venous phase and delayed phase was calculated. ADC histogram analysis was performed and the quantitative parameters were acquired, including the average, standard deviation, median, kurtosis, skewness, and the 10th, 30th,70th, 90th percentile. Qualitative parameters were compared using Fisher exact test. The continuous variables with normal distribution and homogeneous variance were compared by independent sample t test. The continuous variables with skewed distribution were compared by Mann-Whitney U test. The ROC curve analysis was used to evaluate the differential diagnostic ability of the variables with significant differences between HBCA and HBCAC patients. ResultsThere was a statistically significant difference between HBCA and HBCAC in terms of gender, age and whether there was bile duct dilatation or mural nodules （all P〈0.05）. However, the maximum diameter, high signal intensity of the cystic fluid on T1WI and septa of the lesions were not statistically significant （all P〉0.05）. The pCER of arterial phase, portal venous phase and delayed phase of HBCAC patients were higher than those of HBCA patients （all P〈0.05）.The standard deviation of ADC value of HBCAC group was higher than that of HBCA group, while the kurtosis and the 10th percentile were lower than those of HBCA group, and the differences were statistically significant between the two groups （all P〈0.05）. When the 10th percentile value of ADC histogram was ≤ 2.060×10-3 mm2/s, the area under the ROC curve of discriminating between HBCA and HBCAC was the largest （0.861）, and the diagnostic accuracy, sensitivity and specificity were 84.0% and 77.8% and 87.5%, respectively. ConclusionQuantitative multi-phase enhanced MRI combined with histogram analysis of ADC had certain value for the differential diagnosis of HBCA and HBCAC, and the 10th percentile of the ADC histogram had the best diagnostic efficiency.