Chapters 6 and 7

Question 1

Which of the following makes up the majority of the x-ray beam?

Answer 1

Bremsstrahlung.

Question 2

Most of the electrical energy used to produce x-rays results in

Answer 2

heat

Question 3

Filament electrons interact with target atoms to produce x-rays in the following two ways

Answer 3

-charecteristics interactions

-bremsstrahlung (brem) interactions
-majority of x-rays have brems

Question 4

Excess energy is immediately given off as what radiation

Answer 4

infrared (heat)

Question 5

Characteristics interactions involve what?

Answer 5

-filament electrons

-an orbital electron of a target atom

Question 6

What shell is most important

Answer 6

k shell

Question 7

What is the binding tungsten energy for the k shell

Answer 7

69.5 keV

Question 8

Energy

Answer 8

a characteristic or dependent on the difference in binding energy between the shells involved

Question 9

The closer the interaction with the nucleus =

Answer 9

more energy lost (brems photon)

Question 10

higher kVp=

Answer 10

higher brem photon

Question 11

Highest number of x-ray photons produced will be ____ of the kVp you select

Answer 11

1/3

Question 12

Quantity

Answer 12

-number of photons in x-ray

-intensity

Question 13

Inherent filtration

Answer 13

-housing
-window absorbs some of the x-rays

-the target window is the primary contributor

Question 14

Added filtration

Answer 14

-comes in the form of another 2.0 Al placed between the target window and the top of the collimator

Question 15

Total filtration

Answer 15

-2.5 mm is the total filtration needed

Question 16

Beam Quantity

Answer 16

-kVp has bigger impact =15% rule

-the total number of x-ray photons in a beam

-affected by mAs, kVp, distance, & filtration

-varies inversely as the square of the distance

Question 17

Quantity is associated with

Answer 17

radiation dose

Question 18

To adjust quantity you adjust the

Answer 18

mAs
-first to adjust-least effect

Question 19

If kVp is doubled then intensity (quantity) increases by a factor of _____

Answer 19

four

Question 20

Filtration

Answer 20

reduces patient dose by filtering out low energy x-ray photons

Question 21

Beam Quality

Answer 21

-the penetrating power of the x-ray beam

-affected by kVp and filtration

Question 22

Penetration

Answer 22

-refers to those x-ray photons that are transmitted through the body and reach the image receptor

Question 23

Beam Quality Relationship

Answer 23

-goes up in kVp means increased frequency &
shorter wavelength =more penetration

Question 24

As kVp increases, the beam’s ability to penetrate matter also _________

Answer 24

increases

Question 25

Half Value Layer (HVL)

Answer 25

the thickness of absorbing material necessary to reduce the energy of the beam to one half its original intensity

Question 26

What is the normal HVL of a diagnostic beam

Answer 26

3-5 Al

Question 27

Higher kVp =

Answer 27

higher HVL

Question 28

Primary Beam

Answer 28

refers to the x-ray beam as it is upon exiting the collimator and exposing the patient controlled by quantity (mAs) and quality (kVp)

Question 29

Remnant Beam

Answer 29

-refers to the x-ray bean that remains after interaction with the patient and is exiting the patient to expose the image receptor

Question 30

Remnant beams are made of

Answer 30

primary and secondary radiation

Question 31

X-ray Emission Spectrum

Answer 31

-SID and OID does nothing with the emission spectrum or graph -grid does not have to do with emission spectrum

Question 32

Emission Spectrum: characteristic photons are

Answer 32

discrete

Question 33

Emission Spectrum: Brems photon are

Answer 33

continuous

Question 34

Continuous Emission Spectrum

Answer 34

-majority of emission spectrum -brems photons create a bell-shaped continuum

Question 35

Increase mAs =

Answer 35

-increase amplitude -also increases photons -direct relationship

Question 36

5 Factors that change the appearance of the x-ray emission spectrum:

Answer 36

-mA -kVp -tube filtration -generator type -target material

Question 37

An increase in mA increases the amplitude of both the ___________&_____________ portions of the spectrum

Answer 37

-continuous -discrete

Question 38

Changes in kVp effect beam

Answer 38

-quality & quantity -increases the amplitude of continuous & discrete and shifts the wave to the right

Question 39

Process of outer-shell electrons filling inner-shell vacancies continues down the line creating a cascade effect called

Answer 39

characteristic cascade

Question 40

So long as kVp is greater than 69.5, what will happen?

Answer 40

characteristic

Question 41

Bremsstrahlung means?

Answer 41

braking radiation

Question 42

Penetration

Answer 42

x-ray photons that are transmitted through the body and reach the image receptor

Question 43

What are the interactions that happens in the tube

Answer 43

-Bremsstrahlung -Characteristic

Question 44

Classical interactions (coherent or thomson scattering)

Answer 44

-decreases contrast in image (more grey) -no ionization -low kVp = low energy -minimal patient dose

Question 45

Compton interactions

Answer 45

-has ionization -higher kVp -has scatter -has occupational dose (tech gets radiation dose) -has patient dose -creates secondary photon -does not depend on atomic number, it relates to the energy of the photon

Question 46

Photoelectric interactions (very low probability)

Answer 46

-no scatter, everything gets absorbed in the body -has ionization -lower kVps -increases patient dose -has secondary photon (not good for the patient, no effect on operator, image quality is good)

Question 47

Differential absorption

Answer 47

difference between the x-ray photons that are absorbed photoelectrically and those that penetrate the body

Question 48

Transmission

Answer 48

x-ray photons that pass through the body and reach the image receptor

Question 49

Absorption

Answer 49

photons that are attenuated by the body and do not reach the image receptor

Question 50

Radiopaque (spine)

Answer 50

body structures that readily absorb x-rays

Question 51

Radiolucent (lungs)

Answer 51

less dense structures have a much lower probability of absorption