Nonalcoholic fatty liver disease (NAFLD) is a clinicopathologic entity that requires a liver biopsy assessment to diagnose the progressive form of NAFLD termed as nonalcoholic steatohepatitis (NASH). Liver biopsy is invasive, subject to sampling and inter-observer variability and impractical to scale to the affected population of up to 1 billion affected individuals worldwide. Non-invasive imaging biomarkers have emerged as a key modality to address the major unmet need to diagnose, stage and longitudinally monitor NAFLD. In this review, we critically examine the use of non-invasive imaging biomarkers to diagnosis NAFLD, NASH and fibrosis stage. Ultrasound and magnetic resonance imaging (MRI) biomarkers of liver fat can diagnose NAFLD. MRI proton density fat fraction (MRI-PDFF) is better than liver biopsy, particularly for following longitudinal changes in liver fat in the setting of clinical trials. Imaging biomarkers to reliably diagnose NASH are under investigation, but when used alone, continue to have only modest diagnostic accuracy. However, fibrosis stage has the strongest association with liver decompensation and mortality, and elastography has emerged as a reliable biomarker for liver fibrosis. Finally, we review the combination of biomarkers to risk stratify patients and identify individuals needing treatment and the implications of longitudinal changes in liver stiffness measurement.

非酒精性脂肪性肝病 (NAFLD) 是一种临床病理学实体，需要进行肝活检评估以诊断称为非酒精性脂肪性肝炎 (NASH) 的进行性 NAFLD。肝活检是侵入性的，受采样和观察者间差异的影响，并且无法扩展到全球多达 10 亿受影响个体的受影响人群。非侵入性成像生物标志物已成为解决诊断、分期和纵向监测 NAFLD 的主要未满足需求的关键方式。在这篇综述中，我们批判性地研究了使用非侵入性成像生物标志物来诊断 NAFLD、NASH 和纤维化阶段。肝脏脂肪的超声和磁共振成像 (MRI) 生物标志物可以诊断 NAFLD。MRI质子密度脂肪分数（MRI-PDFF）优于肝活检，特别是在临床试验环境中跟踪肝脏脂肪的纵向变化。用于可靠诊断 NASH 的成像生物标志物正在研究中，但单独使用时，其诊断准确性仍然不高。然而，纤维化阶段与肝功能失代偿和死亡率的相关性最强，弹性成像已成为肝纤维化的可靠生物标志物。最后，我们回顾了生物标志物的组合以对患者进行风险分层并确定需要治疗的个体以及肝脏硬度测量纵向变化的影响。肝纤维化阶段与肝功能失代偿和死亡率的相关性最强，弹性成像已成为肝纤维化的可靠生物标志物。最后，我们回顾了生物标志物的组合以对患者进行风险分层并确定需要治疗的个体以及肝脏硬度测量纵向变化的影响。肝纤维化阶段与肝功能失代偿和死亡率的相关性最强，弹性成像已成为肝纤维化的可靠生物标志物。最后，我们回顾了生物标志物的组合以对患者进行风险分层并确定需要治疗的个体以及肝脏硬度测量纵向变化的影响。