traction bronchiectasis

Traction bronchiectasis is what happens to airways when the lung around them shrinks with scar. Imagine fibrous tissue contracting like drying glue and tugging outward on the soft-walled bronchi running through it. Pulled open from all sides, the airways become permanently widened and irregular, even though the airways themselves were not the original problem.

On CT this looks like dilated, distorted bronchi marching through areas of fibrosis, often with a jagged or beaded contour. The key contrast with ordinary bronchiectasis is the cause: here the airway widening is secondary to surrounding scar, not to chronic infection or mucus retention destroying the airway wall directly.

Because it signals retractile, established fibrosis, traction bronchiectasis is an important feature of the usual interstitial pneumonia pattern and a marker of more advanced or progressive interstitial lung disease. Radiologists weigh it alongside honeycombing when assessing how fibrotic a lung has become.

Its presence and extent can also carry prognostic weight, as greater traction bronchiectasis often tracks with worse lung function and outcome. As a feature of fixed scarring rather than active inflammation, it is generally not something that resolves with treatment.