Tree-in-bud sign

Sagittal reformatted CT image showing "tree in bud" appearance of impacted distal small airways in Kartagener Syndrome.

In radiology, the tree-in-bud sign is a finding on a CT scan that indicates some degree of airway obstruction.[1]

The tree-in-bud sign indicates the presence of an infection that has spread endobronchially, and is classically associated with tuberculosis and bronchopneumonia.

Histopathologic studies have shown that the tree-in-bud pattern is caused by demarcation of the normally invisible branching course of the peripheral airways, which usually results from bronchiolar impaction with mucus, pus, or fluid. In addition, dilated and thickened walls of the peripheral airways and peribronchitis can make the affected bronchioles more easily visible, as is seen in patients with cystic fibrosis.

References

  1. Eisenhuber E (March 2002). "The tree-in-bud sign". Radiology 222 (3): 771–2. doi:10.1148/radiol.2223991980. PMID 11867799.

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