Ch. 15 Beam Restriction (Exp II) Flashcards
Scatter radiation in radiography is produced during…
Compton interactions
Scattered photons will…
- Impair image quality
- Add density to image receptor exposure
- Not be considered part of the useful beam
A radiographer can best reduce the amount of scatter radiation from reaching the receptor by…
- Collimating
- Beam restriction
- Utilizing a grid
What can be placed between the patient and the image receptor to absorb scatter radiation?
Radiographic grid
A key factor that affects the amount of scatter produced is…
Kilovoltage
A factor that affects the amount of scatter produced is…
The irradiated material
As the kilovoltage increases, the percentage of x-rays that undergo _____ interactions will increase.
Compton
As the kilovoltage increases, the percentage of photons that undergo a ____ interaction will decrease.
Photoelectric
As more photons pass through the irradiated material unaffected, the resulting image receptor exposure has…
Greater radiographic image density
When more photons are absorbed photoelectrically, the resulting radiograph has…
Less radiographic image density
As the volume of irradiated tissue ____, the amount of scatter produced _____.
Increases; increases
The volume of the irradiated tissue increases as…
Field size and patient thickness increase.
The _____ the atomic number o the irradiated material, the ____ the number of photoelectric absorption interactions will be, and the _____ the scatter produced.
Higher; higher; less
When a beam-restricting device is used to limit field size, technical factors may need to ____ to compensate for the change in image receptor exposure.
Be increased
All off the following are considered beam-restricting devices EXCEPT:
a. Aperture diaphragm
b. Beam filter
c. Positive beam limitation (PBL) device
d. Collimator
b. Beam filter
