Tree-in-bud pattern 2019-01-06T11:14:22Z The tree-in-bud pattern represents centrilobular branching structures that resemble a budding tree. The pattern reflects a spectrum of endo- and peribronchiolar disorders, including mucoid impaction, inflammation, and/or fibrosis (See Figure 70 of PMID:18195376). This pattern is most pronounced in the lung periphery and is usually associated with abnormalities of the larger airways. It is particularly common in diffuse panbronchiolitis, endobronchial spread of mycobacterial infection, and cystic fibrosis. A similar pattern is a rare manifestation of arteriolar (microangiopathic) disease. Pulmonary imaging sign