肝假性淋巴瘤的MRI征象分析

目的：研究肝脏假性淋巴瘤MRI弥散加权成像和动态增强的影像学特征。方法：回顾性分析经病理证实的14例肝假性淋巴瘤患者22个病灶的MRI表现，对MRI各序列信号特征及动态增强各期强化特点进行定性评价。结果：MRI平扫病灶均呈同质性，DWI明显高信号，ADC明显低信号。15个病灶周围沿汇管区DWI呈线性高信号。3个病灶在T2WI和DWI上发现了从病变处沿门静脉延伸的邻近肝实质的楔形水肿信号改变。增强后7个病灶动脉期厚壁环形强化，门脉及延迟期病变内部强化幅度减低，周围持续环形强化；13个病灶动脉期不同程度强化，其中9个病灶轻中度强化、4个病灶明显强化，门脉期及延迟期中央廓清，边缘仍强化；2个病灶动脉期轻中度强化，门脉及延迟期呈等信号。结论：肝脏假性淋巴瘤多小于2cm，信号均匀、弥散明显受限及DCE-MRI不同时期环形强化为其特异性征象，同时病灶周围汇管区DWI线性高信号及沿门静脉邻近肝实质的楔形水肿的发现更有助于肝RLH的诊断。

Magnetic resonance imaging features of hepatic pseudolymphoma

Objective: To study the imaging features of MRI diffusion weighted imaging and dynamic enhancement in hepatic pseudolymphoma. Methods: The MRI manifestations of 22 lesions in 14 cases of liver RLH patients confirmed by pathology were retrospectively analyzed. The characteristics of MRI sequence signals and the characteristics of dynamic enhancement at each stage were qualitatively evaluated .Results: The lesions were homogeneous on MRI plain scans and high DWI signal in all lesions.In 15 patients, linear hyperintensity was observed on DWI along portal area around the lesion. Wedge-shaped signal changes in adjacent liver parenchyma extending from the lesion along portal vein were also observed on T2WI and DWI in 3 lesions. 7 cases showed thick-walled ring enhancement in arterial phase; In 13 cases, the lesions were enhanced to varying degrees in the arterial phase, including 9 cases with mild and moderate enhancement and 4 cases with obvious enhancement, and the portal vein and delayed phase decreased with ring enhancement.In 2 cases, there was mild to moderate enhancement in arterial phase.Conclusion: Liver pseudolymphoma is usually smaller than 2cm, with obvious restricted signal distribution and circular enhancement at different stages of DCE-MRI as its specific signs. Linear high DWI signal in the portal area around the lesion and wedge-shaped edema along the portal vein adjacent to the liver parenchyma are more helpful for the diagnosis of hepatic RLH.