CAMRT Radiography Practice Exam

Decreasing the speed of a screen impacts patient dose in what way?

1. The dose increases

2. The dose decreases

3. There is no effect on dose

4. The outcome varies based on technique

The correct answer is: The dose increases

When considering the impact of decreasing the speed of an imaging screen, it's important to understand the relationship between screen speed and the amount of radiation exposure needed to produce an adequate image. A slower screen speed requires a higher amount of X-ray exposure to produce the same level of brightness on the film or imaging receptor. This means that more X-rays are needed to achieve sufficient image quality, which translates to a greater radiation dose being delivered to the patient. In contrast, faster screens utilize materials that are more efficient at converting X-ray photons into visible light, resulting in less radiation being necessary to achieve similar image quality. This characteristic is foundational in radiography because balancing image quality while minimizing patient dose is a key goal in imaging practices. Thus, decreasing the speed of a radiographic screen leads to an increase in the patient dose due to the requirement of more X-ray exposure to maintain image quality.