How does increasing filtration thickness affect the quality of the x-ray beam?

• A. Decreased quality
• B. Increased quality
• C. No Change in quality
• D. No effect

Answer: (B)

Increasing filtration thickness hardens the beam. It does this by removing more of the low-energy (soft) photons that would be absorbed by the patient without contributing much to image formation. With the soft photons filtered out, the remaining photons are more energetic, so the beam penetrates tissues more effectively. This higher penetrating power is what we mean by increased beam quality, typically reflected by a higher HVL (half-value layer). So the primary effect of adding filtration is to raise the beam’s quality. Keep in mind, though, that removing soft photons can reduce overall image contrast if technique isn’t adjusted, and exposure may need to be compensated to maintain receptor dose.