Peribronchial thickening, also known as peribronchial cuffing, is a term used to describe a hazy radiologic appearance that results from excess fluid or mucus build-up, according to Radiopaedia.org. This build-up happens in the lung's small airway passages and results in patches of collapsed lung.
Periobronchial cuffing is visible around the bronchus or large bronchiole and can be seen on plain film. When excessive mucus or fluid build-up occurs and causes a portion of the lung to collapse, the space around the bronchus becomes more apparent on an X-ray. As Radiopaedia.org points out, another term for the appearance of periobronchial cuffing is a "donut sign." Similar to a donut, the edge of the affected area is thicker while the center is filled with air.
According to Wikipedia, peribronchial cuffing results from a wide range of conditions. Some of the more common examples include pneumonia, acute bronchitis, bronchiolitis, and excessive or extreme physical exertion when exercising. In addition, peribronchial thickening or cuffing can occur due to asthma, particularly following exercise or during an acute attack or episode. Periobronchial thickening is also associated with congestive heart failure, cystic fibrosis, lung cancer, pulmonary edema, Kawasaki disease, smoke inhalation and other conditions or illnesses.
As peribronchial thickening is a sign of an underlying problem, as opposed to a condition or symptom, treatment focuses on the underlying cause of the lung thickening, according to Wikipedia.