Question | Answer |
Define filtration. | Process of eliminating undesirable low-energy x-ray photons by insertion of absorbing materials into the primary beam. |
What is another name for filtration? | Hardening the beam. |
Define filter. | Any material designed to selectively absorb photons from the x-ray beam. |
What is the most common filter used (material): | Aluminum |
How is filtration expressed? (2 methods) | Aluminum equivalency (Al/Eq) and Half-value layer (HVL) |
Define half-value layer. | Amount of absorbing material that will reduce the intensity of the primary beam to one-half of its original value. |
What are the 5 types of filtration? | Added, Compound, Compensation, Total Filtration, Inherent |
What is total filtration? | Filtration that is equal to the sum of inherent and added filtration. (2.5mm Al Eq) |
Define inherent filtration. | Filtration that is a result of the composition of the tube and housing. |
Define added filtration. | Any filtration occurring outside the tube and housing and before the image receptor. |
Materials for added filtration are selected to absorb as many ___ energy photons as possible. | Low |
Typically _______ Al Eq is added to added filtration. | 2.0mm |
Compound filtration uses ______ that complement one another. | two or more materials |
What is another name for compound filters? | K-Edge filters |
Compound filtration places the ______ compound closest to the tube. | highest |
Give an example of compound filtration. | Thoreaus filter |
What is the purpose of compensating filtration? | It is designed to solve a problem involving unequal subject densities. |
What are the two most popular compensating filters? | Wedge and trough |
How are compensating filters designed? | They are designed so that the thicker portion of the filters are matched up with the less dense parts of the body. |