How does increased filtration affect image contrast?

Increased filtration in fluoroscopy refers to the addition of materials that absorb lower-energy X-rays from the beam. These lower-energy photons contribute less to image formation and can increase the overall dose to the patient without significantly enhancing the diagnostic quality of the image.

When filtration is increased, it primarily removes these less useful, low-energy photons from the primary beam. This results in a higher average energy of the X-ray beam, which means that the remaining photons are more likely to penetrate tissues uniformly. As a result, there's a reduction in the differential attenuation of the radiation as it passes through different tissues, leading to a more homogeneous image.

Consequently, the overall effect of increased filtration is a decrease in image contrast. Higher-energy photons tend to traverse through tissues with a more uniform response, resulting in less variation in brightness between different tissues and structures. This diminished contrast can make it more challenging to distinguish between adjacent anatomical features that may have similar attenuation properties. Therefore, the correct answer highlights that increased filtration ultimately decreases image contrast, impacting the diagnostic quality of the fluoroscopic images.