磁敏感加权成像技术鉴别乳头状和嫌色细胞肾癌的价值研究

目的评价磁敏感加权成像(susceptibility weighted imaging,SWI)上肿瘤内磁敏感信号(intratumoral susceptibility signal,ITSS)鉴别乳头状肾癌(papillary renal cell carcinoma,p RCC)和嫌色细胞肾癌(chromophobe renal cell carcinoma,CRCC)的价值。材料与方法对经病理证实的21例肾细胞癌(renal cell carcinoma,RCC)病例(其中p RCC12例,CRCC9例)进行回顾性分析。SWI上的ITSS根据形态分为出血和微血管。采用非参数Mann-Whitney检验比较SWI上p RCC和CRCC的ITSS主要结构、瘤内血管和出血灶数目及ITSS与肿瘤面积比值。采用受试者工作特征(receiver operating characteristic,ROC)曲线分析ITSS4种评价指标鉴别p RCC和CRCC的诊断效能。结果 21例RCC中18例肿瘤内可见ITSS。p RCC的ITSS主要结构的评分显著高于CRCC(P0.05)。p RCC的ITSS与肿瘤面积比值显著高于CRCC(P0.05)。p RCC的瘤内出血灶数目显著多于CRCC(P0.05)。p RCC(100%)瘤内出血的出现率显著高于CRCC(66.67%)。瘤内出血灶数目鉴别p RCC和CRCC的阳性预测值(100%)和特异性(100%)最高,ITSS与肿瘤面积比值鉴别p RCC和CRCC的阴性预测值(87.50%)和敏感性(88.89%)最高。结论通过分析比较ITSS的主要结构、瘤内出血灶和血管数目及ITSS与肿瘤面积比值,SWI可作为评价p RCC和CRCC之间结构差异的有效手段。

Susceptibility weighted imaging in differentiating papillary from chromophobe renal cell carcinoma

Objective:To differentiate papillary RCC (pRCC) from chromophobe RCC (CRCC) based on intratumoral susceptibility signals (ITSSs) detected on SWI.Materials and Methods:A retrospective review was performed on patients with CRCC (n=9) or pRCC (n=12) classiifed by pathology. The ITSSs were classiifed into hemorrhage and microvessels based on their morphology. NonparametricMann-Whitney test was used to compare the differences in the dominant structure of ITSSs, the number of intratumoral vessels and hemorrhagic lesions, and the ratio of ITSS area on SWI between pRCC and CRCC. The diagnostic values of the dominant structure of ITSSs, the number of intratumoral vessels and hemorrhagic lesions, and the ratio of ITSS area on SWI in differentiating pRCCs from CRCCs were compared by receiver operating characteristics (ROC).Results:ITSSs were seen in 18 of 21 patients. No ITSSs were seen in 3 patients with CRCC. Mean scores of dominant structures of ITSSs on SWI were significantly higher for pRCCs than that for CRCCs (P<0.005). There was signiifcant difference of the ratio of ITSS area on SWI between pRCCs and CRCCs (P<0.05). The number of hemorrhagic lesions in pRCCs was signiifcantly larger than that in CRCCs (P<0.05). The occurrence of intratumoral hemorrhage was more common in pRCCs (12/12, 100%) than that in CRCCs (6/9, 66.67%). The number of intratumoral hemorrhagic lesions revealed the highest positive predictive value (100%) and speciifcity (100%) as compared with other features, while the ratio of ITSS area on SWI showed the highest positive predictive value (87.5%) and sensitivity (88.89%).Conclusion:SWI is a useful technique to analyze the structural difference between pRCC and CRCC by the dominant structures ITSSs, the number of intratumoral hemorrhagic lesions, as well as the ratio of ITSS area on SWI.