<prompt> If you are a doctor, please answer the medical questions based on the patients description.Chest x ray PA View: reticular densities are seen in the right upper lung. The heart is not enlarged. The Thoracic aorta is not remarkable. The trachea is at the midline. Both hemidiaphragms and costopheric sulci are intact. The bony thorax is unremarkable. Conclusion: consider an inflammatory process as in koch s infection in the right upper lung. please correlate with other parameters.  <response>: Thanks for your question on Chat Doctor. Reticular densities in upper lobe suggest infective process mostly pneumonia. And upper lobe lesion is most commonly seen in tuberculosis. Tuberculosis is caused by mycobacterium tuberculosis bacteria. And it has great affinity for oxygen. Upper lobes being more oxygenated, favors more infection with TB bacilli. So upper lobe lesion should be rule out for tuberculosis first. So get done sputum examination for AFB to rule out tuberculosis. 