Tree-in-bud almost always indicates the presence of:
Endobronchial spread of infection (TB, MAC, any bacterial bronchopneumonia)
Airway disease associated with infection (cystic fibrosis, bronchiectasis)
less often, an airway disease associated primarily with mucus retention (allergic bronchopulmonary aspergillosis, asthma). #Diagnosis #Radiology #Pulmonary #CTChest #TreeInBud #Differential #RadiologyAssistant