Scatter Reduction Flashcards
The Primary photons which traverse the patient carry…
the image data
The scattered photons…
degrade the image
Scatter_____ image contrast
Scatter reduces image contrast
Ways of reducing scatter
- Collimation
- Patient compression
- Anti-scatter grid
- Air gap technique
- Reduce kVp (increases patient dose)
What is collimation?
reduces the beam filed size therefore decreasing scatter
includes a series of blades made of lead
When is patient compression used, and how does it improve images?
Mammography
It improves both contrast and spatial resolution
What are anti-scatter grids made of?
Composed of lead strips separated by either aluminium
or carbon fibre interspaces
Anti-scatter grids are very thin or thick?
Thin
Which photons can reach the image receptor through the grid?
The photons travelling parallel to the septa
Disadvantages associated with grids
while they improve image contrast they increase patient dose!
