肝脏单发性囊性转移瘤的影像学表现

Imaging findings of intrahepatic single-cystic metastases

目的探讨肝脏单发囊性转移瘤的CT和MRI表现。方法回顾分析14例肝脏单发囊性转移瘤的CT(5例)和MRI(9例)表现。结果肝左叶5例,右叶9例。2例包膜下转移瘤呈扁丘形,其余12例呈圆形或类圆形。肿瘤直径0.7～5.5cm,平均2.7cm。病灶表现为均匀薄壁型2例,均匀厚壁型2例,不均匀厚壁型7例和分隔型3例。病灶的囊壁和分隔CT平扫呈低密度,MRIT1WI呈低信号,MRIT2WI呈高信号、无钙化。12例有强化,3例延迟增强MR扫描呈现外周冲洗现象。病灶囊内部分为水样密度或信号、无强化,3例有液平。病灶通常不伴肝硬化、门静脉栓子以及胆道扩张,但有时同时显示肝外原发肿瘤或者腹部他处转移灶。结论肝脏单发囊性转移瘤具有一定的CT和MRI特征,了解这些特征有助于此类病变的诊断与鉴别诊断。

Objective To investigate the CT and MRI findings of intrahepatic single-cystic metastases（IHSCMs）. Methods CT and MRI findings of IHSCM in 14 patients were retrospectively analyzed.Results The lesions of IHSCM in 5 cases were located in left lobe of the liver,while those in 9 cases were located in right lobe of the liver.The diameters of the lesions ranged between 0.7 cm and 5.5 cm （mean diameter,2.7cm）.Two subcapsular tumors arising from ovarian carcinoma presented as flat shape,while remainder 12 tumors were round or oval.IHSCMs with homogeneous thin wall,homogeneous thick wall,non-homogeneous thick wall ,and intemal septum were found in 2,2,7 and 3 cases,respectively.The cyst walls and intemal septa of all IHSCMs were hypodense without calcification on CT plain scan, hypointensity on MR T1WI and hyperintensity on MR T2WI.On enhanced CT or MR images,the cyst walls and intemal septa of 12 tumors were enhanced.Three tumors had peripheral washout signs on delayed enhanced MR images.On enhanced CT or MR images,the intracystic parts of all IHSCMs had water-like density or signal intensity without enhancement.The intracystic fluid-fluid levels were found in 3 cases.IHSCM usually non-associate with hepatic cirrhosis,portal vein thrombus and bile duct dilatation but it otherwhile may simultaneously reveal the intrabepatic primary tumor or otherwhere abdominal metastases. Conclusion On CT and MR images without and with contrast enhancement,IHSCMs have certain features,while understanding these features is very helpful to diagnose and differentiate this disease.