乳头状肾癌与嫌色细胞肾癌的磁共振成像鉴别诊断

Magnetic resonance imaging in differential diagnosis of papillary renal cell carcinoma and chromophobe renal cell carcinoma

目的探讨磁共振成像(MRI)平扫、三期增强特征及表观扩散系数(ADC)值在鉴别诊断乳头状肾癌(pRCC)与嫌色细胞肾癌(ChRCC)中的价值。方法收集联勤保障部队第900医院2015-06-01-2022-06-01经手术病理确诊的16例pRCC和21例ChRCC临床资料,分析MRI平扫、三期增强特征及ADC值鉴别两者的价值。结果2组病变大小差异无统计学意义,P=0.609;与ChRCC相比,pRCC病灶中心多位于肾轮廓外(P=0.008),并更易出现囊变坏死(P=0.002)。2组病变的ADC值差异无统计学意义,P=0.653;pRCC组皮质期相对强化比值小于ChRCC组,P=0.017;0.258是皮质期鉴别两者的最佳阈值,灵敏度为81.2%,特异度为73.8%。pRCC组髓质期相对强化比值小于ChRCC组,P=0.032;0.353是髓质期鉴别两者的最佳阈值,灵敏度为85.3%,特异度为78.6%。排泄期2组病变的相对强化比值差异无统计学意义,P=0.331。皮、髓质期相对强化比值联合诊断有助于提高鉴别诊断效能,曲线下面积(AUC)为0.887,灵敏度为89.6%,特异度为85.4%。结论pRCC病灶中心多位于肾轮廓外,易出现囊变、坏死。ADC值对2种病变无鉴别价值。MRI增强扫描皮质期、髓质期相对强化比值有助于病变的鉴别。

Objective To explore the value of magnetic resonance imaging plain scan,three phase enhancement characteristics,and apparent diffusion coefficient(ADC)values in the differential diagnosis of papillary renal cell carcinoma(pRCC)and chromophobe cell renal cell carcinoma(ChRCC).Methods Clinical data of 16 cases of papillary renal cell carcinoma and 21 cases of chromophobe cell renal cell carcinoma confirmed by surgery and pathology were collected at the 900th Hospital of Joint Logistics Support Force from June 1,2015 to June 1,2022,and analyzed the value of MRI plain scan,three phase enhancement characteristics,and ADC on differential diagnosis between the two diseases.Results No difference in lesion size between the two groups(P=0.609);Compared to ChRCC,the center of pRCC lesions is mostly located outside the renal contour(P=0.008),and more prone to cystic necrosis(P=0.002);There was no difference in ADC ratio between the two groups of lesions(P=0.653);The relative enhancement ratio in the cortical phase was lower in the pRCC group than in the ChRCC group(P=0.017),and 0.258 was the optimal threshold for distinguishing the two in the cortical phase(sensitivity 81.2%,specificity 73.8%).The relative enhancement ratio of the medullary phase in the pRCC group was lower than that in the ChRCC group(P=0.032);0.353,is the optimal threshold for distinguishing the two in the medullary phase(sensitivity 85.3%,specificity 78.6%).There was no difference in the relative enhancement ratio between the two groups of lesions during the excretion period(P=0.331).The combined diagnosis of relative enhancement ratio in the dermic and medullary phases can improve the differential diagnostic efficacy(AUC 0.887,sensitivity 89.6%,specificity 85.4%).Conclusions The center of pRCC lesions is often located outside the renal contour,which is prone to cystic degeneration and necrosis.ADC values have no differential value for the two lesions.The relative enhancement ratio of cortical and medullary phases is helpful for distinguishing the lesions.