Kamal Omar, Sy Ethan, Chernyak Victoria, Gupta Ayushi, Yaghmai Vahid, Fowler Kathryn, Karampinos Dimitrios, Shanbhogue Krishna, Miller Frank H, Kambadakone Avinash, Fung Alice
Oregon Health & Science University, Portland, OR, USA.
Department of Diagnostic Radiology, Oregon Health & Science University, L340, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA.
Abdom Radiol (NY). 2023 Feb;48(2):519-531. doi: 10.1007/s00261-022-03726-8. Epub 2022 Nov 8.
Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver worldwide. Noninvasive diagnosis of HCC is possible based on imaging features, without the need for tissue diagnosis. Liver Imaging Reporting and Data System (LI-RADS) CT/MRI diagnostic algorithm allows for standardized radiological interpretation and reporting of imaging studies for patients at high risk for HCC. Diagnostic categories of LR-1 to LR-5 designate each liver observation to reflect the probability of overall malignancy, HCC, or benignity based on imaging features, where LR-5 category has > 95% probability of HCC. Optimal imaging protocol and scanning technique as described by the technical recommendations for LI-RADS are essential for the depiction of features to accurately characterize liver observations. The LI-RADS MRI technical guidelines recommend the minimum required sequences of T1-weighted out-of-phase and in-phase Imaging, T2-weighted Imaging, and multiphase T1-weighted Imaging. Additional sequences, including diffusion-weighted imaging, subtraction imaging, and the hepatobiliary phase when using gadobenate dimeglumine as contrast, improve diagnostic confidence, but are not required by the guidelines. These optional sequences can help differentiate true lesions from pseudolesions, detect additional observations, identify parenchymal observations when other sequences are suboptimal, and improve observations conspicuity. This manuscript reviews the optional sequences, the advantages they offer, and discusses technical optimization of these sequences to obtain the highest image quality and to avoid common artifacts.
肝细胞癌（HCC）是全球最常见的原发性肝脏恶性肿瘤。基于影像学特征，HCC的无创诊断成为可能，无需进行组织诊断。肝脏影像报告和数据系统（LI-RADS）CT/MRI诊断算法允许对HCC高危患者的影像学检查进行标准化的放射学解读和报告。LR-1至LR-5的诊断类别用于指定每一个肝脏观察结果，以根据影像学特征反映总体恶性、HCC或良性的可能性，其中LR-5类别HCC的可能性大于95%。LI-RADS技术建议中描述的最佳成像方案和扫描技术对于描绘特征以准确表征肝脏观察结果至关重要。LI-RADS MRI技术指南推荐了T1加权反相位和同相位成像、T2加权成像以及多期T1加权成像的最低所需序列。使用钆贝葡胺作为对比剂时，包括扩散加权成像、减影成像和肝胆期成像等附加序列可提高诊断信心，但并非指南所必需。这些可选序列有助于将真正的病变与假病变区分开来，检测额外的观察结果，在其他序列欠佳时识别实质观察结果，并提高观察结果的清晰度。本文回顾了可选序列及其优势，并讨论了这些序列的技术优化，以获得最高的图像质量并避免常见伪影。
