RTBC Image Evaluation and Quality Control (122) Practice Exam

Increasing filtration in radiography serves to reduce the patient skin dose by eliminating lower-energy x-rays that do not contribute to the formation of a quality diagnostic image. These low-energy x-rays are absorbed by the patient's skin and contribute to skin dose without providing useful information in the resulting image. By enhancing filtration, the beam is "hardened," meaning that only the higher-energy x-rays, which are more likely to penetrate tissues effectively and create a diagnostic image, are allowed to pass through. This adjustment not only reduces the patient's skin dose but also improves overall image quality.

On the contrary, increasing kilovoltage peak (kVp) typically increases the penetration ability of the x-ray beam but may not necessarily reduce the skin dose as effectively as filtration because it could allow more x-rays to reach the patient. A higher grid ratio primarily affects image quality by improving contrast but does not directly impact skin dose. Decreasing the source-to-image distance (SID) usually increases the skin dose because the intensity of the radiation increases as the distance decreases, exposing the patient to a higher dose of radiation.