Midterm Test Flashcards
What is the most effective method to reduce image blur due to pt movement?
Good Communication
Which of the following techniques will result in the highest pt dose?
Low kvp, high grid ratio
Which of the following describes grid ratio?
The height of the lead strips divided by the distance between them.
Which of the following will increase xray beam attenuation?
Increased tissue density & lower kvp
As mAs decreases, the quantity of radiation reaching the IR?
Decreases
Which interaction results in the most pt dose in diagnostic imaging?
Photoelectric effect
Which of the following interactions results in the production of fog?
Compton
For characteristic radiation, an orbital electron must be removed from which shell to produce a useful xray photon?
K Shell
How much total filtration is required for xray tubes that operate above 70kvp?
2.5mm Al
What mA is necessary to produce 24 mAs if you select 0.06 seconds?
400mA
What can the radiographer do to reduce the appearance of noise on a radiographic image
Increase mAs & decrease grid ratio
Which of the following materials is commonly used for beam filtration?
Aluminum
1Which of the following interactions between xray phtons & tissue results in the production of secondary xray photon?
Compton interaction
Why is PBL useful in radiography?
To reduce pt dose by limiting the size of the exposure to the size of the receptor.
A tech receives an exposure of40 mR at a distance of 6 feet from the source of exposure. What is the exposure if they were 3 feet from the source of the exposure?
160 mR
To keep pt dose to a minimum, the tech should use?
Higher kVp, lower mAs.
An xray beam passes through tissue and loses some of its energy. This is known as?
Attenuation
During a photoelectric interaction, the energy of the photoelectron ejected is = to?
Incident photon energy – binding energy.
If the SID Is doubled, what happens to the intensity of the xray beam?
Intensity decreases by a factor of 4.
What happens to the xray emission spectrum when the kvp is increased?
The amplitude increases and the spectrum shifts to the right.
Which of the following occurs when a projectile electron undergoes a characteristic interaction?
An inner shell electron is ionized.
Which interaction, within the diagnostic range, does not involve the removal of an orbital electron?
Classical scattering.
Given the following set of exposure factors (40” SID, 200mA, 0.05 seconds, 70kvp, 0.5” OID), which change would result in the greatest increase in magnification?
4” OID
All of the following are true about Compton scattered photons, except?
If the scattered photon strikes the IR, it will provide useful info.
Which factor listed results in images with a long scale of contrast?
Increased kVp
If the mAs is too low and the number of photons reaching the IR is too few, the image will display which of the following?
More noise
Which of the following is the term used to describe the blurring around the periphery of the image?
Penumbra
The energy of a scattered xray photon is?
less than the energy of the primary beam
Which of the following is a measure of beam quality?
Half value layer
Which of the following describes the production of xrays due to a collision between an incident electron and a k shell electron?
Characteristic interaction