Bronchiectasis can cause lung shadowing. Bronchiectasis is an enlargement of the bronchial lumen caused by a purulent infection of the bronchial wall. Chest X-rays often show increased, thickened and disturbed lung texture and a honeycomb pattern of lung shadows. A high-resolution CT scan of the chest is the gold standard for the diagnosis of bronchiectasis and shows thickening and enlargement of the airway walls.