Subcarinal air cysts refer to small air cysts that can be detected on a CT scan. They are thought to represent small main bronchial diverticula although the former term is preferred 2. They may be associated with chronic airflow limitation.
Patients are asymptomatic and they are often seen on imaging for some other reason.
HRCT - CT chest
They typically have a lobulated margin and can demonstrate ductlike communications between the air cyst and bronchi. Ductlike communications can arise from the posterointerior aspect of the proximal side of the main bronchi; they can be either solitary or multiple. The larger subcarinal air cysts tend to be multiloculated.
If there are relevant clinical factors, consider
- a small pneumomediastinum
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- 2. Higuchi T, Takahashi N, Shiotani M et-al. Characteristics and CT features of subcarinal air collections/main bronchial diverticula. Eur Radiol. 2010;20 (1): 95-9. doi:10.1007/s00330-009-1526-z - Pubmed citation
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