双侧肾血管平滑肌脂肪瘤的CT诊断

目的:探讨双侧肾脏血管平滑肌脂肪瘤(angioleiomyolipoma,AML)的CT表现,提高对其影像学表现的认识及提高诊断准确性。方法:回顾性分析12例确诊双侧肾脏AML的CT表现,包括平扫与动态增强扫描所见。结果:12例病人共有15个AML,根据肿瘤内脂肪成分可分为多、少、很少及无脂肪AML。本组多脂肪AML7个病灶,少脂肪6个病灶,很少脂肪2个病灶。多脂肪AMLCT平扫时即可见肿块内有脂肪成份,密度与皮下或腹膜后脂肪相仿,CT值常为-40～-120HU。少脂肪AML平扫常与肾实质密度相仿,较易漏诊或误诊。采用局部薄层扫描可提高肿瘤内少量脂肪成分的检出机率。很少或无脂肪AMLCT表现酷似肾细胞肾癌,平扫呈低密度肿块,动态增强扫描示肿块皮髓交界期强化不甚明显,实质期肿块中度均匀强化,延迟扫描肿块呈低密度,肿块边缘强化。结论:合理使用病灶局部薄层扫描及动态增强检查技术,CT检查对双侧肾脏血管平滑肌脂肪瘤的诊断准确率较高。

CT diagnosis of bilateral renal angiomyolipoma

Objective:To discuss the CT appearances of bilateral renal angiomyolipoma(AML) and improve the diagnostic accuracy of this disease.Methods:The CT appearances in 12 bilateral renal AML confirmed on clinic were analysed retrospectively,including plain and dynamic CT scans.Results:15 angiomyolipomas in this 12 patients were divided into 3 categories,ie,abundant fat 7 cases,less fat 6 cases and tiny or no fat 2 cases.There was obvious fat in the lesions in plain CT scans with the density about -40~-120 HU.Less fat lesions had the same density as renal parenchyma and prone to be misdiagnosed.However,the technique with thin slice scan in regional area had the more chance of detectable rate.Tiny or no fat lesions had the similar appearances of renal cell carcinoma which had less enhancement in corticomedullary phase and had medium homogenous enchancement in nephrographic phase,the lesions presented as low density mass in delayed phase image. Conclusion:CT technique with thin slice scan and dynamic enhancement in regional area can improve the diagnostic accuracy of AML.