American Registry of Radiologic Technologists (ARRT) Practice Exam

What is the resulting image quality when a fast screen film system is used with a slow screen film automatic system?

1. Underexposed

2. Optimally exposed

3. Too dark or overexposed

4. Blurry and unclear

The correct answer is: Too dark or overexposed

Using a fast screen film system with a slow screen film automatic system generally results in images that are too dark or overexposed. Fast screen films are designed to respond quickly to radiation, producing a significant amount of light for a given exposure. This means they require less radiation to produce an adequate image. On the other hand, a slow screen film system is designed to be more sensitive to the light emitted from the screens, which means it typically requires more radiation to achieve optimal exposure. When a fast film is paired with a slow automatic system, the rapid response of the film can lead to excessive amounts of light being captured. If the settings of the automatic system do not account for the faster response time of the film, the end result can easily be a darker image, indicating that the film may have received more exposure than intended, resulting in overexposure. For a comprehensive understanding, it's important to recognize how the sensitivities of various film and screen combinations interact. This interplay is critical in radiology and can significantly affect the diagnostic quality of the images produced.