What is the primary purpose of diagnostic filtration in radiography?

• A. Increase patient dose
• B. Decrease patient dose
• C. Improve image sharpness
• D. Increase exposure time

Answer: (B)

Diagnostic filtration removes the lowest-energy photons from the x-ray beam. Those soft photons would be absorbed in superficial tissues and skin, delivering dose without meaningfully contributing to image formation. By filtering them out, the beam becomes more penetrating, so you can achieve the same image receptor exposure with less dose to the patient. The result is a safer exposure while maintaining image quality, though technique may be adjusted to compensate for the altered beam intensity. So, the primary purpose is to decrease patient dose.