Thoracic Manifestations of Connective Tissue Diseases.

Connective tissue diseases (CTDs) are a common cause of chronic lung disease, and lung involvement, which can be the initial site of disease, is a major contributor to CTD-related morbidity and mortality. A variety of patterns of acute and chronic lung diseases are associated with CTD including diffuse alveolar damage, organizing pneumonia, diffuse alveolar hemorrhage, usual interstitial pneumonia, nonspecific interstitial pneumonia, and lymphoid interstitial pneumonia. Patients with CTD are also at increased risk for respiratory tract infection and treatment-related complications such as drug-induced lung injury. Radiologists should be familiar with the thoracic manifestation of CTDs so as to identify complications as well as suggest the possibility that CTD may be the underlying cause of lung disease. This article reviews the defined CTDs and describes and illustrates their associated radiographic and computed tomography findings.