肾脏乏脂肪血管平滑肌脂肪瘤的CT和MRI表现

目的探讨肾脏乏脂肪血管平滑肌脂肪瘤的CT和MR特点，以提高对其认识。方法回顾性分析经手术、病理证实的缺乏脂肪肾血管平滑肌脂肪瘤21例的CT和MR表现。11例行CT平扫及双期增强扫描，8例行CT平扫＋增强及MR扫描，2例仅行MR平扫。结果本组21例中，肿瘤最大6．5cm×7．0cm，最小0．8cm×1．0cm。肿瘤与肾实质交界表现为V型17例，杯口样改变4例。CT平扫19例呈高密度16例，等密度2例，呈混杂密度1例。MR检查10例T2wI呈均匀低信号2例，呈等及稍低混杂信号8例；T1WI呈等略低信号，DWI均呈高信号。增强扫描19例强化方式呈快进快出模式16例，呈持续强化模式3例。结论肾脏乏脂肪的血管平滑肌脂肪瘤影像学表现有一定的特征，其密度（信号）、形态及强化方式等有助于和肾癌区别。

The CT and MRI fingings of renal angiomyolipomas with minimal fat

Objective To improve the understanding of renal angiomyoliomas （RAML） with minimal fat by evaluating the CT and MR imagings of it. Methods We selected 21 cases of renal angiomyolipomas with minimal fat confirmed by suraery and pothdogy, retrospectively analyzed the CT and MR imaging findings, llcases were performed with plain CT scan and dual-phase constrast-enhanced CT scan; 8 cases were performed with：plain CT scan and dual-phase constrast-en hanced CT scan and MR; 2 cases were performed with MR only. Results This group consisted of 21 cases. The most le- sions were about 6.5 cm×7.0 cm and the smallest was about 0.8 cru× 1.0 cm. The tumor and renal parenchyma border for V type were 17 cases, and 4 cases were close to cup sign. 16 lesions were high density, 2 were equidensite, and 1 was mixed densities in CT images. 2 cases were low homogeneous signal and 8 cases were moderate or mixed signal on T2 WI; all cases were slightly low signal on TIWI, and all cases were high signal on DWI in MR images. The enhance method of quick scan and quick out were 16 cases, and 3 cases were continuous strengthening mode. Conclusion Lack of fat renal angiomyolipomas imaging findings have certain features, its density （signal）, shape and enhanced mode would help in dif- ferential diagnosis with kidney cancer.