Factors controlling the X-ray beam intensity

Question 1

: Total amount of energy contained in the x-ray beam

Answer 1

Intensity

Question 2

:Number of photons in the beam. Primarily related to tube current and exposure time and less so by tube voltage (kVp) Expressed as: tube current (mA) X time (sec) →mAs

Answer 2

Quantity

Question 3

In relation to quantity and quality, what is the formula for Intensity?

Answer 3

Intensity: Quantity x Quality

Question 4

:Average energy the x-ray beam.▪Controlled primarily by the tube voltage (kVp) X-ray of beam is heterogeneous.

Answer 4

Quality

Question 5

As tube voltage increases, how is number of photons affected?

Answer 5

Number of photons generated increases (increased quantity)

Question 6

As tube voltage increases, how is mean energy of photons affected ?

Answer 6

oMean energy of photons increases (increased quality)

Question 7

As tube voltage increases, how is max energy of photons affected ?

Answer 7

oMaximum energy of photons increases

Question 8

As exposure time increases, how is number of photons affected?

Answer 8

Number of photons generated increases (increased quantity)

Question 9

As exposure time increases, how is mean energy of photons affected?

Answer 9

oMean energy of photons is unchanged

Question 10

As exposure time increases, how is max energy of photons affected?

Answer 10

Maximum energy of photons is unchanged

Question 11

As mA increases, how is number of photons affected?

Answer 11

Number of photons generated increases (increased quantity)

Question 12

As mA increases, how is mean energy of photons affected?

Answer 12

oMean energy of photons is unchanged

Question 13

As mA increases, how is max energy of photons affected?

Answer 13

Maximum energy of photons is unchanged

Question 14

Selectively removes long wavelength (low energy) x-rays.

Answer 14

Filtration

Question 15

_____ x-rays increase the dose of radiation without producing images

Answer 15

Low energy x-rays

Question 16

As filtration increases, how is number of photons affected?

Answer 16

Number of photons decreases (reduced quantity)

Question 17

As filtration increases, how is mean energy of photons affected?

Answer 17

oMean energy of photons increases (increased quality)

Question 18

As filtration increases, how is number of max energy of photons affected?

Answer 18

Maximum energy of photons is unchanged

Question 19

\_\_\_\_ filtration:
o Glass envelope
o Immersion oil
o Metal housing
o Tube window

Answer 19

Inherent filtration

Question 20

_____ filtration:

o Aluminum disks

Answer 20

Added filtration

Question 21

Restricts the size and shape of the beam.

Answer 21

Collimation

Question 22

How does collimation affect number of photons?

Answer 22

oNumber of photons decreases

Question 23

How does collimation affect mean energy of photons?

Answer 23

oMean energy of photons is unchanged

Question 24

How does collimation affect max energy of photons

Answer 24

oMaximum energy of photons is unchanged

Question 25

Intensity of the beam varies inversely to the square of the source-to-receptor distance.

Answer 25

Inverse square law

Question 26

As distance increases, how is number of photons affected?

Answer 26

oNumber of photons decreases (decreased quantity)

Question 27

As distance increases, how is mean energy of photons affected?

Answer 27

oMean energy of photons is unchanged (unchanged quality)

Question 28

As distance increases, how is number of max energy of photons affected?

Answer 28

oMaximum energy of photons is unchanged

Question 29

_____ –altered by factors affecting Quantity of the beam

Answer 29

DENSITY

Question 30

–altered by factors affecting Quality of the beam

Answer 30

CONTRAST

Question 31

oAmount of blackness of an image →Related to how many x-rays reach the receptor
-How dark it is

Answer 31

Density

Question 32

Density is controlled by mAs or kVp?

Answer 32

mAs

Question 33

If the image is darker and has high density, are there more or less x-rays reaching sensor?

Answer 33

More x-rays

Question 34

How are mA and exposure time related?

Answer 34

Inversely proportional

Question 35

o The difference in densities between light and dark regions of a radiograph
o Primarily controlled by the voltage

Answer 35

Contrast

Question 36

Which contrast shows more gray scales?

Answer 36

Low contrast

Question 37

____ contrast:
▪Low kVp(long wavelengths, less penetrating)
▪Density differences between adjacent areas are greater; fewer shades of gray.

Answer 37

High Contrast (Short Gray Scale)

Question 38

_____ contrast:
▪High kVp(short wavelengths, more penetrating)
▪Density differences between adjacent areas are more subtle; more shades of gray.

Answer 38

Low Contrast (Long Gray Scale)

Question 39

High contrast requires ____ kVp

Answer 39

Low kVP

Question 40

Low contrast requires ____ kVp

Answer 40

High kVp

Question 41

If I want to see bone in an x-ray, do you use high or low contrast?

Answer 41

Low contrast

Question 42

If i want to see caries, do you want to use high or low contrast?

Answer 42

High contrast