A versatile role for lung ultrasound in systemic autoimmune rheumatic diseases related pulmonary involvement: a narrative review

Systemic autoimmune rheumatic diseases (SARDs) related pulmonary disease is highly prevalent, with variable clinical presentation and behavior, and thus is associated with poor outcomes and negatively impacts quality of life. Chest high resolution computed tomography (HRCT) is still considered a fundamental imaging tool in the screening, diagnosis, and follow-up of pulmonary disease in patients with SARDs. However, radiation exposure, economic burden, as well as lack of point-of-care CT equipment limits its application in some clinical situation. Ultrasound has found a place in numerous aspects of the rheumatic diseases, including the vasculature, skin, muscle, joints, kidneys and in screening for malignancies. Likewise it has found increasing use in the lungs. In the past two decades, lung ultrasound has started to be used for pulmonary parenchymal diseases such as pneumonia, pulmonary edema, lung fibrosis, pneumothorax, and pleural lesions, although the lung parenchymal was once considered off-limits to ultrasound. Lung ultrasound B-lines and irregularities of the pleural line are now regarded two important sonographic artefacts related to diffuse parenchymal lung disease and they could reflect the lesion extent and severity. However, its role in the management of SARDs related pulmonary involvement has not been fully investigated. This review article will focus on the potential applications of lung ultrasound in different pulmonary scenarios related with SARDs, such as interstitial lung disease, diffuse alveolar hemorrhage, diaphragmatic involvement, and pulmonary infection, in order to explore its value in clinical daily practice.