肾脏上皮样血管平滑肌脂肪瘤的MDCT和MRI表现及其与病理的关系

目的：探讨肾脏上皮样血管平滑肌脂肪瘤（EAML）的MDCT和MRI表现及其诊断价值。方法：对13例经病理证实的肾脏EAMI。患者的MDCT和MRI资料进行回顾性分析，并与手术病理结果对照。9例行CT平扫和动态增强扫描，3例行MRI平扫和动态增强扫描，1例同时行MDCT和MRI检查。结果：13例中8例肿瘤呈实质性，5例呈囊实性。CT平扫示7例病灶呈等密度或高密度，3例呈稍低密度。MRI平扫T1WI上4例病灶以低信号为主，抑脂T2WI上呈低信号或等信号，其中3例信号明显不均匀。CT和MRI增强扫描皮髓交界期示9例病灶呈中等至明显强化，4例轻度强化；实质期示病灶呈持续强化9例，强化程度减退4例，11例病灶强化明显不均匀。仅1例EAML可见少许脂肪信号，6例瘤周可见假包膜显影、较厚且绝大多数完整，9例瘤内可见血管影，4例伴有出血。结论：肾脏EAML的CT和MRI表现具有一定的特征性，特别是T2WI上病灶呈低信号、增强后中等至明显不均匀持续强化、假包膜较厚且完整以及瘤内血管影的显示，有助于提高对EAML的影像诊断准确性。

Renal epitheliod angiomyolipoma..MDCT and MRI features correlated with pathology

Objective： To correlate the image findings of MDCT and MRI for renal epithelioid angiomyolipoma （EAML） with pathology, and to improve the diagnostic accuracy. Methods： 13 cases of patients with renal EAML confirmed by surgical pathology underwent CT （10 cases） and MRI （4 cases） plain scanning and multi phases dynamic enhancement scanning before operation,the CT and MRI data was reviewed and analzsed retrospectively in comparison with surgical and pathological results. Results：There were 8 solid and 5 solid and cystic tumors. On pre-contrast CT scans,7 lesions appeared as isoattenuation or hyperattenuation,and 3 lesions as slight hypoattuation. The tumor presented hypointensity on T1WI, and hypointensity or isointensity on fat suppression T2 WI. 3 of 4 lesions presented obvious inhomogeneous signal intensity both on T1WI and T2WI. The lesions demonstrated moderate to marked heterogeneous enhancement （9 cases） or mild en- hancement（4 cases） on the corticomedullary phase images, delayed enhancement （9 cases） and decreased enhancement （4 cases） on the nephrographic phase,the signal intensity of 11 cases was marked heterogeneous after intravenous injection of the contrast media. No fat attenuation or signal intensity was seen in 12 cases. The thick,intact pseudocapsule （6 cases） and tumor vessels （9 cases） were detected in the lesions and bleeding was detected in 4 cases. Conclusion：The hypointensity on fat suppression T2 WI, moderate to intense heterogeneous progressive enhancement, relatively thick and intact pseudocapsule and intratumor vessels are imaging features of renal EAML,whieh may suggest the diagnosis.