摘要
目的 探讨乏脂肪肾血管平滑肌脂肪瘤（RAML）的MR表现及不同大小RAML间影像特征是否存在差异.方法 回顾性分析2008年1月至2010年3月经手术病理证实的15例乏脂肪RAML的MR影像资料,重点分析T2WI信号强度、均匀度,是否存在假包膜,是否含有脂质,是否存在出血、坏死或囊变,是否存在血管流空影,与肾实质交界是否成角,强化是否均匀.将15例RAML根据病变最大径分为≤4 cm和＞4 cm共2组,用Fisher精确概率统计方法分析2组间影像特征的差异.结果 15个乏脂肪RAML病灶中,T2WI均表现为低信号,信号均匀者6例（6/15）,出现假包膜者3例（3/15）,具有脂质者4例（4/15）,出现囊变者5例（5/15）,有出血表现者5例（5/15）,具有血管流空影者2例（2/15）,病变与肾实质交界面平直,尖端成角者10例（10/15）,均匀强化者8例（8/15）.最大径≤4 cm者9例,最大径＞4 cm者6例.2组病变之间囊变坏死（分别为0和5例）、出血（分别为0和5例）以及假包膜征象（分别为0和3例）差异有统计学意义（P值＜0.05）,而其他征象2组间差异均无统计学意义（P＞0.05）.结论 乏脂肪RAML的MR影像特征主要为T2WI低信号,与肾实质交界面平直,均匀强化.病变因大小不同MR征象可以存在差异.
Objective To document the MRI features of renal angiomyolipoma （RAML） containing minimal fat and to explore whether the MR features vary depending on the tumor size. Methods The MR findings of 15 cases of pathologically-proved RAML containing minimal fat were reviewed retrospectively from January 2008 to March 2010. All patients underwent MR in a 1.5 T or 3.0 T scanners. The MR features of the lesions were analyzed, with emphasis on the signal intensity and homogeneity on T2WI, in regards to pseudocapsule, lipid component, hemorrhage, cystic degeneration or necrosis, blood vessels, interface with renal parenchyma and enhancement pattern. All lesions were categorized into 2 groups; those with diameter ＞4 cm and those with diameter ≤4 cm. The difference of imaging characteristics between these two groups was analyzed using Fisher exact test. Results All 15 lesions demonstrated hypointensity on T2WI compared to the renal parenchyma. Homogeneous signal intensity on T2WI was seen in 6 lesions （6/15）; peritumoral pseudocapsule in 3 lesions （3/15）; cystic degeneration or necrosis, hemorrhage in 5 lesions （5/15）; flow void of blood vessels in 2 lesions （2/15）; lipid component in 4 lesions （4/15）; angular interface with renal parenchyma in 10 lesions （10/15）; homogeneous enhancement in 8 lesions （8/15）. Fifteen lesions were divided into two groups; 9 categorized into group 1 （the maximum diameter ≤ 4 cm） and 6 into group 2 （ the maximum diameter ＞ 4 cm）. Cystic degeneration or necrosis was seen in 0 of 9 in group one and 5 of 6 in group two respectively, hemorrhage（0 of 9 and 5 of 6 respectively） and pseudocapsule（0 of 9 and 3 of 6 respectively. The difference between these findings in the two groups demonstrated statistical significance （P ＜ 0. 05）. Conclusion The MR features of RAML containing miminal fat were hypointensity on T2 WI,angular interface with renal parenchyma and homogeneous contrast enhancement, however, these findings can vary depending on the tumor size.
出处
《中华放射学杂志》
CAS
CSCD
北大核心
2010年第12期1268-1271,共4页
Chinese Journal of Radiology
关键词
肾肿瘤
磁共振成像
Kidney neoplasms
Magnetic resonance imaging
