Tram tracks, bull’s eye, buds on a tree, honeycomb… Do you know you can find all these in a lung?
Here is a list of metaphorical terms that describe signs and patterns of lung disease on X-ray or CT images.
➕ Tram-track sign
- thickened non-tapering (parallel) walls of cylindrical bronchiectasis (more info & images on radiopaedia.org, including differentiation from tram-track signs in other parts of the body)
➕ Mosaic attenuation pattern
- a patchwork of regions of differing pulmonary attenuation on CT imaging (more info & images on radiopaedia.org)
➕ Tree-in-bud
- CT appearance of multiple areas of centrilobular nodules with a linear branching pattern (more info & images on radiopaedia.org)
➕ Ground-glass opacification/opacity (GGO)
- a descriptive term referring to an area of increased attenuation in the lung on computed tomography (CT) with preserved bronchial and vascular markings (more info & images on radiopaedia.org)
➕ Bulls-eye
- central ground glass opacity surrounded by an inner ring of air and an outer ring of ground glass in the right lower lobe (see an example in a scientific publication); a more common name is "pulmonary target sign" (radiopaedia.org)
➕ “Honeycomb” lung / honeycombing
- a CT imaging descriptor referring to clustered cystic air spaces (between 3 and 10 mm in diameter, but occasionally as large as 2.5 cm) that are usually subpleural, peripheral, and basal in distribution (more info & images on radiopaedia.org)
➕ Crazy paving
- ground-glass opacities with superimposed interlobular septal thickening and intralobular septal thickening, seen on chest HRCT or standard CT chest (more info & images on radiopaedia.org)
➕ Bat wing / butterfly / angel wing
- symmetrical perihilar ground-glass opacities with a wing-like shape (see an example in a scientific publication)
➕ Comet tail
- a curvilinear opacity that extends from a subpleural "mass" toward the ipsilateral hilum (more info & images on radiopaedia.org)
➕ Galaxy sign
- a coalescent granuloma seen in a minority of patients with pulmonary sarcoidosis (more info & images on radiopaedia.org)
Have you encountered other metaphorical terms in pulmonology? You're welcome to share them in the comments.
