Radiologic approach and progressive exploration of connective tissue disease-related interstitial lung disease: meeting the curiosity of rheumatologists.

Interstitial lung disease (ILD) is often observed in connective tissue diseases (CTDs), frequently in rheumatoid arthritis, systemic sclerosis, primary Sjögren's syndrome, and inflammatory myositis. Early detection of ILDs secondary to rheumatic diseases is important as timely initiation of proper management affects the prognosis. Among many imaging modalities, high-resuloution computed tomography (HRCT) serves the gold standard for finding early lung inflammatory and fibrotic changes as well as monitoring afterwards because of its superior spatial resolution. Additionally, lung ultrasound (LUS) and magnetic resonance imaging (MRI) are the rising free-radiation imaging tools that can get images of lungs of CTD-ILD. In this review article, we present the subtypes of ILD images found in each CTD acquired by HRCT as well as some images taken by LUS and MRI with comparative HRCT scans. It is expected that this discussion would be helpful in discussing recent advances in imaging modalities for CTD-ILD and raising critical points for diagnosis and tracing of the images from the perspective of rheumatologists.