<unk>  is an abnormality on a chest x-ray whereby the usually thin bronchial walls are thickened and take on a doughnut-like appearance.
Peribronchial cuffing
Lymphocytic interstitial pneumonia
Bronchial hyperresponsiveness
Adenoid hypertrophy
Nodular lesions
Desquamative interstitial pneumonia
Interstitial edema
Mediastinal lipomatosis