Exam 2 Flashcards
X-rays were discovered by:
Roentgen
The first ever x-ray was of:
A hand
Which factors if changed, change x-ray quantity?
(1) mAs
(2) kVp
1 and 2
Which factors affect x-ray quality?
(1) kVp
(2) mAs
- kVp
At a higher kilovoltage (kVp) the percentage of photoelectric interactions:
-Decreases
-Increases
-Does not change
Decreases
Which of the following tissue interactions is responsible for patient dose of ionizing radiation?
Photoelectric
Interaction between a projectile electron and the nucleus of the target atom
Bremsstrahlung interaction
Interaction between a projectile electron and an inner shell electron
Characteristic interaction
X-rays photons are produced at any projectile electron energy creating a continuous emission spectrum.
Bremsstrahlung interaction
Interaction creates a discrete emission spectrum.
Characteristic interaction
Requires at least 70 kVp.
Characteristic interaction
In the diagnostic range, most X-ray are created from the _____.
Bremsstrahlung interaction
the energy of the primary beam (quality or quantity)
x-ray quality
the number of X-rays in the primary beam (quality or quantity)
x-ray quantity
T/F: interactions in the x-ray tube that produce x-rays occur at the atomic level, and the nature of the x-ray photon produced depends on how an electron interacts with an atom
True
T/F: interactions between the x-ray photons and the human body occur at the atomic level, determining both the radiation dose delivered and how the body part will be imaged
True
T/F: x-ray photons interact at the atomic level of the image receptor to generate the manifest image.
True
The shift of the characteristic x-ray spectrum to higher energy occurs because of [x] in kVp.
an increase
The probability of the incident photon having a Compton scattering interaction is influenced principally by:
-the atomic number of the tissue
-energy of the incident photon
-both the atomic number of the tissue and the energy of the incident photon.
The energy of the incident photon
The photoelectric effect is principally associated with the [absorption/ scattering] of an x-ray photon.
Absorption
The percentage of Compton interaction [x] with increasing energy (higher kVp) of the incident x-ray photon.
Increases
The Compton interaction involves outer shell electrons due to their [x] binding energy.
Low
In reference to target interactions, only kVp settings of [x] or greater will produce K characteristic photons
70
Increasing kVp [z] x-ray beam quality.
Increases
In the characteristic interaction, a [a] interacts with an anode atom.
Filament electron
In order to remove an inner shell orbital electron, the filament electron must have kinetic energy [x] than the binding energy of the electron with which it interacts
greater
Changes in kVp have a/an [direct/indirect] effect on beam quality and penetrability.
Direct
Beam [z] refers to the energy level or penetrability of the x-ray beam.
Quality
After Compton scattering, the scattered x-ray has [less/more] energy than it had before the interaction.
less
The photoelectric interaction is an interaction with [o].
an inner-shell electron
T/F: A change in mA changes the number of electrons flowing from the cathode to the anode.
True
T/F: A change in mA changes the kinetic energy of electrons flowing from cathode to anode.
False
X-ray transmission decreases, which also means that the x-ray beam becomes [more/less] penetrating
Less
a decrease of intensity of the x-ray beam
Attenuation
varies the size of the radiation field
collimator
stops a moving part in a specific location
Detent
Unseen image
latent image
Seen image
manifest image
surrounds x-ray tube, lead lined
tube housing
source of x-rays
x-ray tube
direction and location of radiation; predictable and controllable
Primary radiation
Radiation difficult to control
scatter radiation
pattern creates the x-ray image
exit radiation
squared area of the x-ray beam that strikes the patient
radiation field
beam that is unattenuated
primary
what remains of the beam after it has been attenuated
remnant
travels in all directions from the patient
scatter
area of radiation protection (where does the technologist go to make the exposure?)
Control booth
Anatomic structures that do not readily transmit x-rays are called [z].
Radiopaque
Anatomic structures that readily transmit x-rays have a [x] atomic number.
low
Decreasing tissue atomic number [x] beam attenuation.
Increases
Increasing kVp [z] transmission.
Increases
Differential absorption is the difference between those x-rays that are absorbed and those that are [z].
Transmitted
[z] refers to x-rays leaving the patient that did not interact with atoms as it passed through the patient.
Transmission
What is the source of energy that results in characteristic photons?
Potential energy of the electron filling the vacancy
The attenuation of x-rays occurs:
Exponentially
As kVp increase, the
1. wavelength is shorter
2. wavelength is longer
3. more of the beam is in the higher energy range (in regards to the primary beam spectrum)
1 and 3
An x-ray beam is heterogeneous, this means
the beam consists of different energy levels
