CAMRT Radiography Practice Exam

How should exposure technique be modified for a patient with a suspected pneumothorax requiring a portable chest x-ray?

1. Increase exposure time

2. Decrease exposure settings

3. Maintain original technique

4. Use a higher kVp

The correct answer is: Decrease exposure settings

In cases of suspected pneumothorax, the primary goal of imaging is to achieve a clear visual representation of the pleural space. As air in the pleural cavity can lead to a decreased density difference on radiographs, modifying the exposure settings is essential for optimal image quality. Decreasing the exposure settings, particularly the milliampere-seconds (mAs), is crucial because a pneumothorax typically requires less radiation exposure. This adjustment assists in reducing the risk of overexposing the sensitive lung tissues, which may be more susceptible to radiation, particularly in emergency situations. Furthermore, a lower exposure helps enhance the visibility of air in the pleural space against the surrounding anatomical structures. Using an increased kVp could help penetrate the air surrounding the pneumothorax, but decreasing the overall exposure settings is most effective for balancing image contrast and quality while protecting the patient from unnecessary radiation exposure. Adjusting exposure time is less effective than modifying the mAs and kVp specifically for these patients. Maintaining the original technique may not yield the necessary contrast, making it difficult to assess the suspected condition accurately.