Fig. 1

a and b: In a 70-year-old male patient with known rheumatoid arthritis, a fibrosing NSIP pattern is observed in high-resolution computed tomography scans taken at 7-year intervals. In axial sections taken from the lung bases, irregularities are observed to become evident in the subpleural area consistent with fibrotic changes (black arrowheads). Interlobular septal lines are seen as tiny lines outlining secondary pulmonary lobules forming polygonal shapes in both scans (white arrows). They are more prominent in the later section in figure b due to progressive fibrosis. In consecutive sections, an increase in ground- glass opacities (asterix) are visible, as well as traction bronchiectasis (black arrows)