CAMRT Radiography Practice Exam

In which scenario is expiration used for a chest x-ray?

1. To detect vertebral fractures

2. To show pleural effusion

3. To assess diaphragm excursion

4. To evaluate cardiac shadow

The correct answer is: To assess diaphragm excursion

Expiration is used for a chest x-ray primarily to assess diaphragm excursion. When a patient exhales, the diaphragm moves upward, reducing the volume of the thoracic cavity and allowing for a clearer view of its position and movement. This technique is crucial for evaluating the mobility of the diaphragm, which can indicate the presence of conditions such as diaphragmatic paralysis or other respiratory issues. In the context of other scenarios, detecting vertebral fractures, showing pleural effusion, and evaluating cardiac shadow typically rely on different techniques or patient positioning, where the focus is on other anatomical structures rather than diaphragm movement. For instance, pleural effusion is often better visualized on an upright inspiratory view, which can demonstrate fluid levels more clearly. Therefore, using expiration specifically supports the evaluation of diaphragm function and excursion.