The clinical importance of interstitial lung abnormality (ILA) is increasingly recognized. In July 2020, the Fleischner Society published a position paper about ILA. The purposes of this article are to summarize the definition, existing evidence, clinical management, and unresolved issues for ILA from a radiologic standpoint and to provide a practical guide for radiologists. ILA is a common incidental finding at CT and is often progressive and associated with worsened clinical outcomes. The hazard ratios for mortality range from 1.3 to 2.7 in large cohorts. Risk factors for ILA include age, smoking status, other inhalational exposures, and genetic factors (eg, gene encoding mucin 5B variant). Radiologists should systematically record the presence, morphologic characteristics, distribution, and subcategories of ILA (ie, nonsubpleural, subpleural nonfibrotic, and subpleural fibrotic), as these are informative for predicting progression and mortality. Clinically significant interstitial lung disease should not be considered ILA. Individuals with ILA are triaged into higher- and lower-risk groups depending on their risk factors for progression, and systematic follow-up, including CT, should be considered for the higher-risk group. Artificial intelligence-based automated analysis for ILA may be helpful, but further validation and improvement are needed. Radiologists have a central role in clinical management and research on ILA.

© RSNA, 2021

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间质性肺异常 (ILA) 的临床重要性日益得到认可。2020 年 7 月，Fleischner 协会发表了一份关于 ILA 的立场文件。本文的目的是从放射学的角度总结 ILA 的定义、现有证据、临床管理和未解决的问题，并为放射科医师提供实用指南。ILA 是 CT 中常见的偶然发现，通常是进行性的，并与临床结果恶化有关。在大型队列中，死亡率的风险比在 1.3 到 2.7 之间。ILA 的危险因素包括年龄、吸烟状况、其他吸入暴露和遗传因素（例如，编码粘蛋白 5B 变体的基因）。放射科医师应系统记录 ILA 的存在、形态特征、分布和亚类（即非胸膜下、胸膜下非纤维化和胸膜下纤维化），因为这些有助于预测进展和死亡率。临床上显着的间质性肺病不应被视为 ILA。ILA 患者根据其进展的风险因素被分为高风险和低风险组，并且应考虑对高风险组进行包括 CT 在内的系统性随访。基于人工智能的 ILA 自动化分析可能会有所帮助，但需要进一步验证和改进。放射科医生在 ILA 的临床管理和研究中发挥着核心作用。ILA 患者根据其进展的风险因素被分为高风险和低风险组，并且应考虑对高风险组进行包括 CT 在内的系统性随访。基于人工智能的 ILA 自动化分析可能会有所帮助，但需要进一步验证和改进。放射科医生在 ILA 的临床管理和研究中发挥着核心作用。ILA 患者根据其进展的风险因素被分为高风险和低风险组，并且应考虑对高风险组进行包括 CT 在内的系统性随访。基于人工智能的 ILA 自动化分析可能会有所帮助，但需要进一步验证和改进。放射科医生在 ILA 的临床管理和研究中发挥着核心作用。

© 北美放射学会，2021

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