A 62-year-old woman comes to the physician because of an 8-month history of shortness of breath on exertion and non-productive cough. She has no past medical history and takes no medications. She is a non-smoker. She recently retired from her position as a career lawyer. FVC is 46% of predicted. A chest x-ray shows fine linear opacities bilaterally. A high-resolution CT of the chest is shown.
Which of the following is the most likely diagnosis?
Asthma
Atypical pneumonia
Bronchiectasis
Emphysema
Usual interstitial pneumonitis
