Question

An expiration PA chest radiograph is most often included in the evaluation of a potential pneumothorax. The reason for this is:

a. To assess diaphragm movement
b. To reduce lung volume
c. Increase lung volume of the unaffected area
d. To increase the area the pneumothorax occupies

Answer 1

An expiration PA chest radiograph can help increase the visibility of a pneumothorax by increasing the space it occupies as the lungs decrease in volume and intrapulmonary pressure rises during expiration, separating the pleural layers further.

Step-by-step explanation:

An expiration PA chest radiograph is most often included in the evaluation of a potential pneumothorax. The primary reason for this is to increase the area the pneumothorax occupies. During expiration, the thoracic cavity and lungs decrease in volume, which increases the intrapulmonary pressure. The higher pressure can cause a pneumothorax to become more evident on the radiograph by pushing the pleural layers apart and allowing excess air to move into the potential space, thus increasing its size and making it easier to detect.