Radiology 5, 6, And 7

Front 1

What 4 things do you need to produce an x-ray?

Back 1

Filimant(source of elrctrons), target(anode),

vacuum,

high potential energy difference

Front 2

What type of x- rays are produced(2)

Back 2

1)Bremsstrahlung- Comes close, stops, and changes direction

2)Characteristic- Outer shell electron colides with an innershell electron

Hint 2

Brem=break

Front 3

What percent of the electron interaction is actually converted to x-rays?

Back 3

<(less than) 1% =x-rays

99% =heat

Front 4

What's the relationship called between actual, and effective focal spots?

Back 4

Mind focus principal

Front 5

2 types of filtration?

Back 5

1)Adamant filtration

2)Inherent filtration

Front 6

What does an auto transformer do?

Back 6

Vary the voltage to the primary side to the step up transformer.

Front 7

What in the tube gives us or electrons?

Back 7

Filament in the cathode(negative)

Front 8

How much more efficient is the single phase from the three phase generators?

Back 8

40% more effective

Front 9

Three types of rectification

Back 9

1)self rectification

2)full wave

3)half wave

Hint 9

We don't normally use

Front 10

Kvp

Back 10

Higher kvp= long scale

Lower kvp= short scale

Front 11

Heterogeneous

Back 11

Different wave lengths & energies

Front 12

Hu factors (equations)

Back 12

••Single phase: Hu= mA×time×kvp

••Three phase: Hu= mA×time×kvp×1.35

••High frequency: Hu= mA×time×kvp×1.40

Front 13

Density

Back 13

Overall blackness

Front 14

What is the main purpose of filtration?

Back 14

To reduce patient dose.

Front 15

What is the x-ray tube housing made of?

Back 15

Pyrex glass

Front 16

The unit used to indicate the total quantity of x-rays in an exposure is:

Back 16

Milliampete seconds(mAs)

Front 17

The mass density of a body part is referred to as:

Back 17

Tissue density

Front 18

Roentgen discovered x-rays while working with a(n) _____ tube.

Back 18

Crookes tube

Front 19

An "electron cloud" surrounding the filament of the cathode is referred to as a:

Back 19

Space charge

Front 20

Free electrons for x-ray production come from the:

Back 20

Filament

Front 21

The creation of the space charge in the x-ray tube produces:

Back 21

Thermionic emission

Front 22

The majority of photons I the x-ray beam are created by which process?

Back 22

Bremsstrahlung interactions

Front 23

More than 99% of the energy of the electron stream is converted into:

Back 23

Heat

Front 24

The high-speed rotation (10,000 rpm) of the anode enables:

Back 24

Greater dissipation of heat from high technical factors.

Front 25

The degree of angulation of the x-ray tube target will determine the:

Back 25

Size of the actual and effective focal spot.

Front 26

A dual- focus x-ray tube has:

Back 26

Two filaments, and two focal spot sizes.

Front 27

The anode heel effect is a phenomenon of x-ray production that results in:

Back 27

Uneven distribution of radiation within the x-ray field.

Front 28

The penetrating power of the x-ray beam is controlled by varying the:

Back 28

Peak kilovoltage(kVp)

Front 29

The rate of current flow across the x-ray tube is measured in:

Back 29

mA(milliamperes)

Front 30

Doubling the mA will result in:

Back 30

Increased patient dose, twice as many photons in the x-ray beam, & increased radiographic density

Front 31

The unit used to indicate the total quantity of x-ray exposure is:

Back 31

Milliampere- seconds(mAs)

Front 32

An x-ray exposure is made using the following factors: 200 mA, 0.02 seconds, 70 kVp, 40 inches SID.

The value of the mAs for this exposure is:

Back 32

4

Front 33

The device for removing long- wavelength radiation from the primary x-ray beam is the:

Back 33

Filter

Front 34

The purpose of rotating the anode of the x-ray tube is to:

Back 34

Increase the heat capacity of the needle.

Front 35

Image sharpness is determined by the:

Back 35

Size of the effective focal spot.

Front 36

Above 70 kVp, what percentage of photons is created by the bremsstrahlung process?

Back 36

85%

Front 37

The amount of detail seen in the x-ray image is referred to as:

Back 37

Spatial resolution

Front 38

Tungsten

Back 38

•high melting pint

•high dissipation of heat

Front 39

What is meant by thermionic emission, and what is its purpose in the x-ray tube?

Back 39

Process that causes charged particles to be go in off when heat is applied.

Purpose= create x-rays

Front 40

What happens if any x-ray beam has an increase in kVp?

Back 40

•greater energy

•greater penetrating power

Front 41

Standard rotation speed of the x-ray tube's anode?

Back 41

3600rpm

Front 42

What is the percentage characteristic radiation that is produced below 70kVp?

Back 42

None, characteristic radiation can only be produced above 70kVp.

Front 43

Primary purpose of filtration?

Back 43

Reduce patient dose.

Front 44

Three components of the x-ray tube that contribute to inherent filtration:

Back 44

•oil

•pyrex glass

•mirror

Front 45

Term used to describe the heating of an element to a hot temperature a d the expanding of elections in the atom?

Back 45

Thermionic emission

Front 46

High speed anode used for:

Back 46

Heat dissipation

Front 47

What are two rotation speeds for the anode?

Back 47

3,600, and 10,000

Front 48

All of the following devices are located within the low-voltage circuit and control console except the:

Back 48

Step up transformer

Front 49

The autotransformers primary purpose is to vary the:

Back 49

Voltage

Front 50

Which Transformer is located in the filament circuit?

Back 50

Step-down transformer

Front 51

The primary purpose of the filament circuit is to:

Back 51

Heat the X-ray tube filament for thermionic emission

Front 52

A timer that is capable of producing ultra-short short exposure times is typical of an

Back 52

Electronic timer

Front 53

The primary purpose of a rectifier in a X-ray circuit is to:

Back 53

Change alternating current(AC) into direct current(DC).

Front 54

The primary purpose of the high-voltage circuit is to:

Back 54

Supply the X-ray tube with voltage high enough to produce x-rays.

Front 55

The advantage of using high frequency generator instead of a single phase generator include:

Back 55

•producing xrays more efficiently

•requiring less exposure time to produce a given amount of exposure

• producing the greatest amount of x-rays for the same exposure technique.

Front 56

How much can the exposure time be decreased when using three phase X-ray equipment?

Back 56

40%

Front 57

Automatic exposure control(AEC) automatically varies the:

Back 57

Exposure time

Front 58

If the automatic exposure control fails during the exposure the _____will terminate the exposure:

Back 58

Rectifier

Front 59

For which type of X-ray exposure system can the technical factors be programmed into the system?

Back 59

Automatically programmed radiography(APR)

Front 60

How much higher is the percentage of x-rays produced in a 3-phase x-ray machine?

Back 60

40%

Front 61

In a high-frequency x-ray generator, the standard 60-Hz frequency is increased to about:

Back 61

6000 Hz

Front 62

The highest-power x-ray generator is the:

Back 62

High frequency generator

Front 63

Public law 90-602

Back 63

Public law 90-602 states that generators must terminate the exposure time at 600 mAs for exposure above 50 kvp.

Front 64

Full wave rectification

Back 64

•In full wave rectification, there are 120 pulses in 1 second

•Exposure time can be cut in half

Front 65

Ways the X-ray tube life can be extended:

Back 65

•Warm up the anode

•Do not hold down the rotor switch for a long periods of time

•Use low mA settings whenever possible

•Do not make repeated exposures near the tube limits

•Do not use a tube when you can hear the rotor bearings

Front 66

What is the name of the device used to provide rectification in the X-ray circuit?

Back 66

Diode

Front 67

Two things that occur when the rotor switch is activated:

Back 67

•Anode spins

•Thermionic emission

Front 68

The process of changing AC to DC:

Back 68

Rectification

Front 69

How many pulses of radiation occur in a full wave rectified x-ray machine?

Back 69

120 pulses per second

Front 70

What is the most modern x-ray generator used today?

Back 70

Full wave rectifier

Front 71

Which x-ray generator has the lowest power?

Back 71

Single phase

Front 72

The unit used to indicate the total quantity of x-rays in an exposure is:

Back 72

Milliampere- seconds(mAs)

Front 73

Which of the following will result in increased radiographic density?

Back 73

•Increased mA

•Increase exposure time

•Decreased Source image receptor distance(SID)

Front 74

The mass density of the body part is referred to as:

Back 74

Tissue density

Front 75

The primary controller of radiographic density is:

Back 75

mAs

Front 76

The difference in radiographic density between any two adjacent portions of the image is called:

Back 76

contrast

Front 77

The primary factor controlling radiographic contrast and x-ray penetration is:

Back 77

kVp

Front 78

High contrast produced by using low kVp results in an image with:

Back 78

A short scale of contrast

Front 79

Generalized unwanted exposure on the image called:

Back 79

Fog

Front 80

A decrease in SID will result in:

Back 80

Increased magnification

Front 81

A misrepresentation of the size or shape of the structure being examined is called:

Back 81

Distortion

Front 82

The fuzzy unsharpness at the edges of structures or body parts is called:

Back 82

Penumbra

Front 83

The smaller the effective focal spot, the _____ the penumbra, and the _____ the spatial resolution.

Back 83

Less, greater

Front 84

What a large OID used spatial resolution can be improved by:

Back 84

•Increasing the SID

•Maintaining the small focal spot

Front 85

Fog affects radiographic quality by causing:

Back 85

Decreased contrast

Front 86

A term used to describe a grainy or mottled image is:

Back 86

Quantum mottle

Front 87

One means of controlling distortion is by controlling the:

Back 87

Part position

Front 88

Which of the following will affect the quality of the X-ray beam?

Back 88

kVp