Barrel chest does not represent an advanced stage of emphysema, but is one of the main features of emphysema. Most cases of emphysema are characterized by barrel-shaped chests, and a chest CT may show signs of increased lung translucency and pulmonary blisters. Barrel chest does not indicate the presence of respiratory failure and heart disease, which are usually associated with advanced emphysema, and therefore does not indicate advanced emphysema. Patients with emphysema may need to undergo tests such as lung function, blood gas analysis and cardiac ultrasound to assess the severity of the disease. The above tests are helpful in determining whether emphysema is in an advanced stage.