American Registry of Radiologic Technologists (ARRT) Practice Exam

In radiology, what is the primary purpose of aluminum filtration?

1. To enhance image quality

2. To reduce patient exposure to radiation

3. To maintain image brightness

4. To increase beam intensity

The correct answer is: To reduce patient exposure to radiation

The primary purpose of aluminum filtration in radiology is to reduce patient exposure to radiation. Filtration refers to the process of removing low-energy X-ray photons from the primary beam. These low-energy photons contribute to patient dose without increasing diagnostic quality; they are less penetrating and more likely to be absorbed by the patient's tissue, leading to unnecessary exposure. By filtering out these low-energy photons, aluminum filtration increases the overall quality of the X-ray beam. The result is that only higher-energy photons that are more effective in producing diagnostic images reach the patient, thereby minimizing their radiation dose. This practice is essential not just for patient safety, but also for improving the efficiency of the imaging process. The other options, while relevant to different aspects of radiology or imaging techniques, do not correctly define the primary function of aluminum filtration. Enhancing image quality, maintaining image brightness, or increasing beam intensity are not the primary goals of filtration. Instead, filtration is specifically designed to optimize the balance between imaging effectiveness and patient safety through careful management of radiation exposure.