American Registry of Radiologic Technologists (ARRT) Practice Exam

Filtration affects the primary beam in x-ray imaging by selectively removing low-energy photons. These low-energy x-rays contribute little to no diagnostic information but increase patient dose because they are absorbed by the body without producing useful images. By using filtration, typically aluminum or other materials, the average energy of the x-ray beam increases, as the resulting beam is composed of higher-energy photons that can penetrate the tissues more effectively. This helps ensure that the x-ray images produced have better diagnostic quality while also reducing the exposure to the patient by eliminating unnecessary low-energy photons.

As a result, the overall quality of the x-ray study is enhanced, leading to improved image clarity and reduced radiation exposure. This principle is essential in radiographic practice to optimize both patient safety and image efficacy.