You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Bronchiectasis with predominantly upper lobe involvement is and explain in detail?
More pronounced involvement of the upper lung fields is most common in cystic fibrosis(CF) and is also observed in post radiation fibrosis,corresponding to the lung region encompassed by the radiation po.Bronchiectasis with predominant involvement of the lower lung fields is seen in fibrotic lung diseases or hypogammaglobulinemia.Congenital causes of bronchiectasis with predominant midlung field involvement include the dyskinetic/immotile cilia syndrome or Kaagener's syndrome.Finally,predominant involvement of the central airways is repoed in association with allergic bronchopulmonary aspergillosis. Ref:Harrison's medicine-18th edition,page no:2142.