肝脏影像报告和数据系统(LI-RADS)中MRI辅助特征的解读

Interpretation of the magnetic resonance imaging ancillary features in Liver Imaging Reporting and Data System(LI-RADS)

增强MRI是临床常用的对肝细胞癌(HCC)进行准确诊断和分期的无创性检查方法。HCC的典型表现为动脉期明显强化和门静脉/平衡期廓清,但直径<20 mm的结节常表现为非典型的强化模式。肝脏影像报告和数据系统(LI-RADS)描述了一些影像辅助特征来帮助诊断,包括非特异性恶性特征(轻至中度T2高信号、DWI扩散受限、病灶中乏脂、病灶中乏铁、直径增加小于阈值生长和晕环状强化)及HCC特异性征象(病灶内含脂、结节中结节、马赛克结构和出血)。现就上述MRI影像辅助特征进行详细阐述。

Contrast-enhanced magnetic resonance imaging(MRI) is a commonly used non-invasive examination for the accurate diagnosis and staging of hepatocellular carcinoma(HCC). Imaging features for HCC diagnosis rely on hyper-enhancement in the arterial phase and washout in the portal or equilibrium phase. However, the nodules of diameter <20 mm often appear as atypical enhancement patterns. The Liver Imaging Reporting And Data System(LI-RADS) describes some ancillary features to help diagnosis, which includes non-specific features suggesting malignancy(mild to moderate T2 hyperintensity, restricted diffusion in diffusion weighted imaging, lesional fat sparing, lesional iron sparing, diameter increase less than threshold growth and corona enhancement) and HCC-specific features(intra-lesional fat, nodule-in-nodule architecture, mosaic architecture and blood products). These MRI ancillary features are elaborated.