Which of the following pathological conditions would require a decrease in exposure technique?

The correct choice highlights a situation in which a decrease in exposure technique is needed due to the presence of a pneumothorax. In this condition, air becomes trapped in the pleural space, which can lead to a decrease in the effective density of the thoracic cavity. This reduction in density means that less radiation exposure is required to produce a diagnostic image.

When imaging a patient with a pneumothorax, the technician must adjust the exposure settings to account for the increased radiolucency (less dense areas) created by the air in the pleural space. As a result, a lower exposure technique helps to avoid overexposure of the image, ensuring that the presence of a pneumothorax is clearly visible without overwhelming the diagnostic details.

In contrast, the other conditions may require different techniques. For example, pneumonia involves increased fluid and density within the lung tissue, necessitating increased exposure to properly visualize the affected areas. Similarly, cholecystitis, which often involves inflammation of the gallbladder, requires careful consideration of exposure based on the density of surrounding tissues. A fractured rib might not need as drastic a change, but still wouldn’t typically require a decrease in exposure due to the structure's density that needs to be evaluated