肝细胞腺瘤磁共振成像影像特征分析

Magnetic resonance imaging features of hepatocellular adenoma

目的探讨肝细胞腺瘤的MRI影像特征。方法回顾性分析浙江省温州市中医院和浙江省温州市人民医院2013年1月至2018年5月连续经病理证实的36例肝细胞腺瘤患者资料,男性14例,女性22例,年龄27~85(46±4)岁。观察肿瘤部位、大小、形态、信号、增强后强化方式等。结果36例中肿瘤位于肝右叶23例,肝左叶10例,肝左右叶3例;肿瘤呈椭圆形15例,圆形12例,结节状9例。肿瘤最大直径2.0~11.0(4.8±2.6)cm。于T1加权成像(T1WI)呈低信号21例,等信号11例,稍高信号4例;T2加权成像(T2WI)呈高或稍高信号33例,等信号3例;T2WI脂肪抑制序列呈高或稍高信号32例,等信号4例;弥散加权成像(DWI)呈稍高信号24例,等信号12例。病灶于T2WI呈高信号环,中心呈相对低信号的"环礁征"11例。瘤周假包膜30例,瘤内坏死液化11例,瘤内出血8例。增强后动脉期肿瘤均匀强化22例,不均匀强化14例,动脉期显著强化16例,中度强化15例,轻度强化5例。门静脉期肿瘤信号高于周围正常肝实质7例,等于肝实质12例,低于肝实质17例。延迟期肿瘤信号高于肝实质信号1例,等于肝实质18例,低于肝实质17例。肿瘤假包膜于门静脉期和延迟期强化30例,无强化6例。结论肝细胞腺瘤多呈圆形或椭圆形,T1WI低信号,T2WI、T2WI脂肪抑制及DWI呈高或稍高信号;增强动脉期显著强化,门静脉期和延迟期轻度强化,有"环礁征"、瘤周假包膜有助于诊断。

Objective To study the magnetic resonance imaging(MRI)features of hepatocellular adenomas(HCA).Methods The MRI images of 36 patients who were diagnosed to have HCA by pathology at Wenzhou Chinese Medicine Hospital and Wenzhou People’s Hospital between January 2013 to May 2018 were reviewed retrospectively.There were 14 males and 22 females,age ranged from 27 to 85(46±4)years.The location,size,morphology,signal intensity and enhancement modes of tumors were observed.Results For plain scans of MRI:among 36 patients,the lesions of 10,23 and 3 patients respectively were located in the left,right and both left and right hemilivers.The lesions of 15,12 and 9 patients were round-like,oval-like and nodular shape,respectively.The maximum diameter ranged from 2.0 to 11.0(4.8±2.6)cm.T1 weighted imaging(T1WI)of 21,11,and 4 patients showed low signal,iso-signal,and slightly high signal,respectively.T2 weighted imaging(T2WI)of 33,and 3 patients showed high,or slightly high signal and iso-signal,respectively.T2WI on fat-suppression of 32 and 4 patients showed high,or slightly high signal and iso-signal,respectively.Diffusion weighted imaging(DWI)of 24,and 12 patients showed high or slightly high signal and iso-signal,respectively.T2WI of 11 patients showed a high signal ring while the center had a relatively low signal,called the"atoll"sign.Of the 36 patients,30 had a peritumoral low-signal pseudo-envelope,11 had intratumoral necrosis,and 8 had intratumoral hemorrhage.On dynamic contrast enhancement scanning:the arterial phase of 22 and 14 patients showed uniform enhancement and uneven enhancement,respectively,while 16 lesions showed significant enhancement,in 15 patients moderate enhancement,and in 5 patients mild enhancement.In the portal venous phase of 7,12 and 17 patients,the tumor signals were higher,equal and lower than the liver parenchyma signal,respectively.In the delayed phase of 1,18 and 17 patients,the tumor signals were higher,equal and lower than the liver parenchyma,respectively.In the portal vein and delayed phase,30 and 6 patients,the pseudocapsules showed mildly enhanced and no enhancement,respectively.Conclusion HCA is mostly round or oval,T1WI low signal,T2WI,T2WI fat suppression and DWI showed high or slightly high signal.Significant enhancement of arterial phase enhancement,mild enhancement of portal phase and delayed phase,a"atoll sign"and a peritumoral pseudocapsule are helpful for diagnosis.