Ch. 8 Test Flashcards
What type of radiation is used to create the useful parts of a diagnostic image?
exit and remnant radiation
T/ F - Beam interactions are not affected by beam quality and quantity.
false
The image contained within the imaging receptor before it is processed into the final image is called the ____ image.
latent
Image formation is the result of_____ absorption.
differential
What are the three form of attenuation?
absorption, scatter, transmission
T/F - The primary beam is what creates digital images.
False
T/F - Ionization is the process through which an atom ejects a neutron, gaining a net charge.
false
In the diagnostic range, absorption occurs through a process called______.
photoelectric effect
T/F - During a photoelectric event, the x-ray photon loses energy, and is able to exit the body.
False
T/F -
Higher kVp = Less scatter
Lower kVp = More scatter
False
T/F - The x-ray photon does not lose energy during a coherent scatter event.
true
The primary beam is a ______ beam.
heretogenous
During this form of attenuation, the beam passes through the body with no interaction with atomic structures.
transmission
What form(s) of attenuation make up the final image
transmission and absorption
Scatter causes an effect on the final image that is called _______.
fog
In regards to the patient, which of the following impact beam attenuation
part thickness, tissue type, tissue density
T/F - Energy level of the beam impacts attenuation.
true
Beam attenuation increases roughly __% for each 4-5 cm of increased tissue thickness.
50%
Thicker anatomic structures require ___ radiation.
more
Tissues comprised of atoms with low atomic numbers present ____ opportunities for scatter or absorption to occur.
less
This is the amount of matter per unit volume.
density
_____ tissue is more dense than ____ tissue
- Air-filled, fat
- Muscle, fat
- Muscle, bone
- Air-filled, bone
muscle, fat
An x-ray beam’s quality is also referred to as it’s ____
penetrability
T/F - Absorption tends to occur with high energy photons.
false
T/F - Remnant radiation is only the radiation that transmits through the body without energy loss.
false
Absorption is responsible for the ____ color of an image
white
Transmission is responsible for the ____ color of an image
black
Scatter is responsible for the ____ color of an image
grey
T/F - High contrast means the image has a lot of greyscale.
false
T/F - Low contrast means the image is mostly black and white.
false
Less than __% of the primary beam reaches the image receptor
5%
Exit radiation is directly used to create the ____ image
latent
T/F - Film-screen, CR, and DR all use cassette-based technology.
false
This form of digital radiography uses an imaging plate that is scanned in a reader.
computed radiography
In terms of dynamic range, a ____ range is preferred.
wide
T/F - Because digital algorithms can correct an image that has been over-exposed, it isn’t important for radiographers to be precise when selecting kVp and mAs.
false
Which of these items are preferred in a digital radiography image receptor?
small pixel size and large matrix size
T/F - It is best to have as small of a bit depth as possible.
false
T/F - Film-screen has a much wider dynamic range than digital radiography.
false
T/F - Fluoroscopy produces static images only.
false
T/F - Dynamic imaging allows us to see internal structures of the body in motion.
true
The x-ray tube of a fluoroscopy unit is typically ____
below the table top
