Smoking-Related Interstitial Lung Disease: CT Image-Based Review and Update

Tobacco smoking is the leading cause of preventable deaths in the United States. Beyond the risks of cardiovascular disease and several cancers, smoking contributes to lung inflammation, lung destruction, and smoking-related interstitial lung diseases (SRILD). SRILD describes a broad range of conditions that includes respiratory bronchiolitis, respiratory bronchiolitis-associated interstitial lung disease, desquamative interstitial pneumonia, pulmonary Langerhans cell histiocytosis, acute eosinophilic pneumonia, idiopathic pulmonary fibrosis, combined pulmonary fibrosis and emphysema, interstitial lung abnormality, and smoking-related interstitial fibrosis. Computed tomography (CT) is central to the diagnosis and understanding of clinicopathologic manifestations of smoking-related lung injury. Common features of SRILD on CT include low-attenuation areas, ground-glass opacities, fibrosis, and lung nodules. Although the various SRILDs are often described as distinct entities, they may manifest with nonspecific features or exhibit mixed patterns and may more accurately be described as a continuum of pathology. Understanding the broad range of radiologic features and recognizing the potential coexistence and overlap of disease processes is essential to maintaining an appropriate differential diagnosis. In this article, we review the radiologic findings associated with SRILDs with a focus on diagnostic considerations and challenges when interpreting CT images.