肾脏透明细胞癌与乏脂血管平滑肌脂肪瘤CT影像鉴别

CT Differential Diagnosis of Clear Cell Renal Carcinoma and Fat-Poor Angiomyolipoma

目的:探究肾脏透明细胞癌(clear cell renal cell carcinoma,ccRCC)与乏脂血管平滑肌脂肪瘤(fat-poor angiomyolipoma,fp-AML)的动态增强CT表现以及鉴别诊断。方法:收集2019年3月~2021年11月就诊并术后病理证实的23例ccRCC患者和7例fp-AML患者,对其术前平扫及动态增强CT图像进行分析,评价肿瘤影像特征如囊变、假包膜、坏死出血、钙化,测量肿瘤实性部分在扫描各期CT值,计算皮质期强化率,进行独立样本t检验。结果:ccRCC患者CT影像上更易观察到假包膜、囊变坏死及钙化。平扫时ccRCC肿瘤平均CT值为(31.04±9.63)Hu,fp-AML肿瘤平均CT值为(37.57±2.99)Hu,两组平扫CT值差异有统计学意义(P<0.05)。增强扫描皮质期强化率ccRCC高于fp-AML肿瘤,两者差异具有统计学意义(P<0.05)。皮质期、实质期、排泄期各期CT值,ccRCC患者与fp-AML患者均无统计学差异(P>0.05)。结论:假包膜、囊变坏死及钙化的出现对肾透明细胞癌有诊断价值,而平扫时肿瘤的密度、增强扫描皮质期强化率对于ccRCC和fp-AML鉴别有进一步帮助。

Objective:To explore the dynamic enhanced CT findings and differential diagnosis of clear cell renal cell carcinoma(ccRCC)and fat-poor angiomyolipoma(fp-AML).Methods:Collected 23 ccRCC patients and 7 fp-AML patients who were diagnosed with postoperative pathology from March 2019 to November 2021,analyzed their preoperative plain scan and dynamic enhanced CT images,and evaluated tumor imaging features such as cystic degeneration,pseudocapsule,necrosis and hemorrhage,calcification,CT value of the solid part of the tumor was measured in each phase of the scan,the cortical phase enhancement rate was calculated,and the independent sample t test was performed.Results:Pseudocapsules,cystic degeneration,necrosis and calcification are easier to be observed on CT images of ccRCC patients.The average CT value of ccRCC tumor during plain scan was(31.04±9.63)Hu,and the average CT value of fp-AML tumor was(37.57±2.99)Hu.There was a statistically significant difference in CT values between the two groups(P<0.05).The enhancement rate of ccRCC in the cortical phase was higher than that of fp-AML tumors,and the difference between the two was statistically significant(P<0.05).There was no significant difference in CT values of cortical phase,parenchymal phase and excretory phase between ccRCC patients and fp-AML patients(P>0.05).Conclusion:The appearance of pseudocapsule,cystic necrosis and calcification is valuable for the diagnosis of renal clear cell carcinoma,and the tumor density during plain scan and the enhancement rate of cortical phase in enhanced scan are further helpful for the differentiation of ccRCC and fp-AML.