American Registry of Radiologic Technologists (ARRT) Practice Exam

What is the main purpose of filters in a film badge?

1. To enhance image quality

2. To measure radiation quality

3. To provide a protective barrier

4. To calibrate imaging equipment

The correct answer is: To measure radiation quality

The primary role of filters in a film badge is to measure radiation quality. When radiation interacts with the film, the filters absorb specific energies of the incoming radiation before it reaches the film itself. Different materials and thicknesses of filters will allow certain energies to pass while attenuating others. This selective absorption enables dosimetry to assess not only the quantity of radiation exposure that a person has received but also the type and quality of that radiation. This measurement is vital for monitoring occupational exposure in environments where different types of radiation may be present—such as X-rays, gamma rays, or beta particles—allowing for better assessment of potential biological effects. Understanding the quality of radiation exposure is crucial because it can influence the likelihood of biological damage, establishing the importance of using filters in the accurate evaluation of a radiologic technologist's exposure to radiation.