不均匀度在肾乏脂肪血管平滑肌脂肪瘤与肾透明细胞癌CT鉴别中的价值研究

  目的  探讨不均匀度在肾乏脂肪血管平滑肌脂肪瘤(angiomyolipoma with minimal fat, mfAML)与肾透明细胞癌(clear cell renal cell carcinoma, ccRCC)鉴别诊断中的价值。  方法  回顾性分析中国科学院大学附属肿瘤医院(浙江省肿瘤医院)2016年1月—2019年10月经病理证实的25例mfAML和45例ccRCC患者的CT增强扫描图像, 测量肿瘤和腰大肌的不均匀度(HDT/HDP)并获得标准化肿瘤不均匀率(SHRT), 同时测量增强各期肿瘤及肾皮质的CT值并获得肿瘤强化率(ERT), 对2种肿瘤间各参数的差异进行统计学分析。绘制受试者工作特征(ROC)曲线, 评价各个参数的诊断效能。  结果  mfAML的皮质期HDT及SHRT、实质期HDT、排泄期HDT及SHRT均低于ccRCC, 差异有统计学意义(均P＜0.05), 2组肿瘤的平扫HDT及SHRT、实质期SHRT间的差异无统计学意义(均P＞0.05)。mfAML的平扫CT值高于ccRCC, 而皮质期ERT低于ccRCC, 差异有统计学意义(均P＜0.05);2组肿瘤的皮质期CT值、实质期和排泄期CT值及ERT间的差异均无统计学意义(均P＞0.05)。ROC曲线显示定量参数中的皮质期HDT及皮质期SHRT的ROC曲线下面积较大, 其AUC值分别为0.85及0.82。当皮质期HDT取31.31 Hu为截断值时, 其鉴别2种肿瘤的敏感度为84.4%, 特异度为72.0%。  结论  不均匀度可以作为一种简便的反映强化均匀性差异的定量指标来对mfAML与ccRCC进行鉴别, 其中皮质期不均匀度的诊断价值较高。 

The value in differentiation of renal angiomyolipoma with minimal fat and clear cell renal cell carcinoma by using CT heterogeneous degree

  Objective  To investigate the value of heterogeneous degree in differential diagnosis of renal angiomyolipoma with minimal fat (mfAML) and clear cell renal cell carcinoma (ccRCC).  Methods  CT scan images of mfAML (n=25) and ccRCC (n=45) confirmed by pathology in Cancer Hospital of University of Chinese Academy of Sciences (Zhejiang Cancer Hospital) were retrospectively collected and analyzed from January 2016 to October 2019. The heterogeneous degree of tumor and psoas (HDT/HDP) were measured and standardized heterogeneous rate of tumor (SHRT) was obtained. The CT value of tumor and renal cortex in each enhanced phase were measured and enhancement rate of tumor (ERT) was obtained. The difference of parameters between the two tumors were statistically analyzed. The receiver operating characteristic (ROC) curve was drawn to evaluate the diagnostic efficacy of each parameter.  Results  HDT and SHRT of cortical phase, HDT of nephrographic phase, and HDT and SHRT of excretory phase in mfAML were all lower than that in ccRCC, the difference was statistically significant (all P < 0.05). There was no statistically significant difference in HDT and SHRT of pre-contrast phase and SHRT of nephrographic phase between the two groups (all P>0.05). The CT value of pre-contrast phase in mfAML was higher than ccRCC, while the ERT of cortical phase in mfAML was lower than ccRCC, the difference was statistically significant (all P < 0.05). There was no statistically significant difference in CT value of cortical phase, CT value and ERT of nephrographic phase and CT value and ERT of excretory phase between the two tumors (all P>0.05).The ROC curve showed that the area under curve (AUC) of HDT & SHRT in cortical phase was larger, with AUC values of 0.85 and 0.82 respectively.When HDT of cortical phase took 31.31 Hu as the cutoff value, the sensitivity to distinguish these two tumors was 84.4%, and its specificity was 72.0%.  Conclusion  The heterogeneous degree can be used as a simple quantitative index to reflect the difference in enhanced homogeneity to distinguish mfAML from ccRCC, among which the diagnosis value of heterogeneous degree in cortical phase is higher.