Pediatric Bronchiectasis Etiology: irreversible dilation of the airwaysCT: inspiratory – diameter of bronchus > diameter of adjacent pulmonary artery, expiratory – look for air trapping Radiology Cases of Bronchiectasis Axial CT without contrast of the chest shows extensive bronchiectasis throughout the lungs. CXR shows linear cystic changes in the lingula and left lower lobe posteriorly which were chronic in nature. Gross Pathology Cases of Bronchiectasis Gross pathological image of a sectioned lung shows marked dilation of the airways in the middle and lower lung with many of the dilated airways containing mucous within them.