肝脏孤立性坏死结节的CT、MRI表现及病理特点分析

MRI and CT findings and pathology features of solitary necrotic nodule of the liver

目的探讨肝脏孤立性坏死结节(SNNL)的影像学特点,提高对该病的诊断水平。方法回顾性研究63例经病理确诊的SNNL影像学资料,分析病灶的CT与MRI表现。结果63例SNNL中15例行CT检查,43例行MRI检查,5例同时行CT和MRI。共发现结节67个,位于肝右叶46个,左叶18个,中叶3个;结节大小为0.4~12.4 cm。CT平扫23个结节均呈低密度,其中1个结节旁钙化灶;MRI平扫49个结节呈T1WI等低信号;40个结节呈T2WI高信号,5个呈T2WI等信号,4个呈T2WI低信号。3个受伪影干扰,3个呈DWI等信号,1个呈DWI低信号,其余42个均呈DWI高信号。CT及MRI增强延迟期病灶呈边缘持续强化42个,内部分隔强化9个。病理确诊的67个结节中17个为凝固性坏死,50个为液化坏死。结节切面呈灰白色或黄白色,无组织细胞结构,周边有纤维组织包绕。结论肝脏孤立性坏死结节典型特征为好发于肝右叶,直径<3 cm,DWI均为高信号。凝固性坏死结节T1WI呈低信号,T2WI呈高信号;液化坏死结节T1WI呈低信号,T2WI呈高信号。CT和MRI延迟期边缘持续强化或有分隔强化有助于该病的诊断,部分不典型表现仍需要依靠病理检查。

ObjectiveTo investigate the imaging features of solitary necrotic nodule of the liver(SNNL)and improve the diagnosis of the disease.MethodsThe imaging findings of 63 patients pathologically confirmed SNNL were retrospectively analyzed with the manifestations of CT and MRI.ResultsIn the 63 SNNL cases,15 patients underwent CT,43 underwent MRI and 5 concurrently performed CT and MRI.A total of 67 nodules were found,46 in the right lobe of the liver,18 in the left and 3 in the middle lobe,the nodules ranged in size from 0.4 cm to 12.4 cm.CT plain scan showed 23 nodules with low density,including one paranodular calcification.All 49 nodules on T1WI were iso-hypointensity;40 nodules on T2WI were hyperintensity,5 were isointensity and 4 were hypointensity.Except for 3 nodules of artifact interference,42 nodules were hyperintensity on DWI,3 were iso-intensity and 1 was hypointensity.The edge of the 42 lesions continue to strengthen in the delay phase,and 9 lesions showed septa enhancement in the dynamic contrast-enhanced scan with CT and MR.Pathological examination confirmed 17 nodules as coagulative and 50 as liquefactive necrosis.The cut surfaces of the nodules appeared gray-white or yellow-white,lacking cellular structure and surrounded by fibrous tissue.ConclusionsThe typical characteristics of solitary necrotic nodules of the liver include a predilection for the right lobe,a diameter of less than 3 cm,and hyperintense signals on DWI.Coagulative necrosis nodules show hypointense signals on T1WI and hyperintense on T2W1,while liquefactive necrosis nodules show hypointense signals on T1WI and hyperintense signals on T2WI.Continuous peripheral enhancement or septal enhancement in the delayed phase of CT and MRI helps in diagnosing this condition,although some atypical presentations still require pathological examination.