成人后肾腺瘤的CT与MRI表现

CT and MRI manifestations of adult renal adenoma

目的探讨后肾腺瘤(MA)的CT、MRI特征,以提高对MA的诊断准确率。方法选取术后病理证实的13例MA患者的CT和MRI表现。结果13例中男性2例,女性11例,发生在肾皮质10例,皮髓质区3例。实性7例(53.8%),囊实性6例(46.2%),其中3例病灶内见分隔,含钙化4例(30.8%)。10例行CT扫描,实性部分平扫呈等或稍高密度;8例行MRI扫描,T_(2)WI有完整假包膜2例,不完整假包膜4例,无假包膜2例,DWI均呈高信号,ADC值减低,T_(1)WI呈等或稍低信号,3例内见出血,T_(2)WI呈等-稍低或稍高信号。增强扫描病灶呈轻中度渐进性延迟强化,强化程度均低于正常肾实质,分隔持续强化。其中1例伴腹膜后淋巴结转移。结论MA多发生于中年女性,呈外生性生长,实性或囊实性,呈轻中度渐进性延迟强化,囊实性的病灶内可有分隔,可伴钙化。CT与MRI检查相结合可以提高该病的诊断准确率。

Objective To investigate the CT and MRI findings of metanephric adenoma so as to improve the diagnostic accu‐racy.Methods The CT and MR findings of 13 cases of MA with pathologically-confirmed were analyzed.Results The 13 pa‐tients included 2 males and 11 females.10 cases occurred in the renal cortex and 3 cases in the corticomedullary region.Seven le‐sions were solid.Six lesions were cystic solid and septum was seen in 3 cases.Calcification was found in 4 cases.Ten cases under‐went CT scan.Plain scan of solid part showed equal or slightly high density.Eight cases underwent MRI scan,two lesions showed complete pseudocapsules on T_(2)WI and 4 incomplete pseudocapsule.DWI showed high signal,ADC value decreased.T_(1)WI showed equal or slightly lower signal intensity,hemorrhage was seen in 3 cases.T_(2)WI showed equal-lower or slightly higher sig‐nal on MRI.The lesions showed mild to moderate progressive enhancement on enhanced scan,of which 2 cases showed centrip‐etal filling enhancement.The enhancement degree was lower than that of normal renal parenchyma.One case was accompanied by retroperitoneal lymph node metastasis.Conclusion It is highly suspected of the possibility of metanephric adenoma when we see a solid or cystic solid renal mass with exogenous growth,accompanied by calcification,showing mild to moderate progres‐sive enhancement in middle-aged women.The cystic solid lesions may have internal partitions.The combination of CT and MR can improve the diagnostic accuracy of the disease.