<prompt> A patient presents with haemoptysis, copious sputum and tram lines abnormal air bronchogram pattern on the chest X-ray. What is the most likely diagnosis?Lung abscessPulmonary embolism with infarctionBronchiectasisCarcinoma of lung  <response>: The most common clinical presentation of bronchiectasis is a persistent productive cough with ongoing production of thick,tenacious sputum.Acute hemoptysis is an impoant complication of bronchiectasis.Chest CT is the imaging modality of choice for bronchiectasis,and it shows airway dilation,detected as parallel tram tracks or as the signet-ring sign- a cross sectional area of the airway with a diameter at least 1.5 times that of the adjacent vessel, lack of bronchial tapering, bronchial wall thickening in dilated airways, inspissated secretions TREE IN BUD SIGN or cysts emanating from bronchial wallCYSTIC BRONCHIECTASIS Reference:Harrisons medicine-18th edition,pa no:2142,2143. 