Radi 1130 1St Assesment

Front 1

Image acquisition

Back 1

Absorbed by tissue, scattered random radiation, and transmitted by hitting IR

Front 2

mAs

Back 2

Amount of radiation. More x-ray photons if mA or time is increased.
High mA= burnout
Low mA= speckles, quantum mottle

Front 3

kVp

Back 3

Strength of radiation.
Better for patient than mAs but worse for rad. tech.
Higher kVp= shorter wavelength=higher frequency

Too high kV= burnout
Low kV= no penetration

Front 4

X-rays

Back 4

Behave like particles when interacting with matter.
Ionizing and non-ionizing
No mass or charge
Travel in straight line
Can't be focused by lens

Front 5

Photons

Back 5

Bundle of energy. Each carry their own specific amount of energy, this depends on their frequency. Energy and frequency are directly proportional

Front 6

Excitation

Back 6

X-ray's transfer energy to atom. Electrons move to a higher energy level within atom and will drop back down to original energy level to maintain atom stability.

Front 7

Ionization

Back 7

X-ray with energy greater than the binding energy removes electron from atom. Can disrupt metabolic relationships within body ( atomically changes cells)

Front 8

Ionizing radiation

Back 8

Can be ionizing and excitation.
EMR ( X-ray, gamma)
Particulate (alpha, beta, neutron)

Front 9

Electromagnetic radiation (EMR)

Back 9

No mass or charge. X-rays are man made and gamma are from radioactive nuclei.

Front 10

Particulate radiation

Back 10

Mass and charge
Alpha= +, mass, can't travel far
Beta= -, almost no mass, from radio. Nuclei, like high speed electrons. Most dangerous.

Front 11

Radiation production

Back 11

Occurs when high speed electrons are stopped abruptly at target. 2 types
1) bremsstrahlung
2) characteristic

Front 12

Bremsstrahlung

Back 12

When incident electrons interact with force field of nucleus. Can't penetrate force field so the electron slows rapidly = 99% heat and 1%
x-rays emitted. The farther away the interaction from nucleus the weaker the xray. Creates various high and low energy X-rays
Creates 80-90% diagnostic X-rays.

Front 13

Characteristic radiation

Back 13

Radiation that relates to levels of shells.
Incident electron interacts with inner shell electron, electron is removed, this ionizes the atom making it unstable.
This causes electron from higher energy shell to drop and fill lower energy inner shell. Results in energy difference between the 2 shells.
The farther the electron drops the higher the X-ray energy.
Electrons continue dropping down from higher shells= characteristic cascade, until only outer shell missing electron.
Predictable but X-rays not very diagnostic 10-20%
More characteristic X-rays seen above 70kVp ( energy level needed to remove k shell electron from tungsten)

Front 14

Generators

Back 14

Converts mechanical energy to electrical energy.

Front 15

Generators

Back 15

Converts mechanical energy to electrical energy.

Front 16

Autotransformer

Back 16

Varies incoming voltage. Have primary and secondary coils

Front 17

Generators

Back 17

Converts mechanical energy to electrical energy.
AC to DC = rectification
Falling load generator

Front 18

Autotransformer

Back 18

Varies incoming voltage. Have primary and secondary coils

Front 19

Transformers

Back 19

1) step up = increase voltage to kilo-voltage

2) step down = decrease incoming voltage for filament

Front 20

3 types of phase generators

Back 20

1) 3 phase 6 pulse = ripple if 13-25%

2) 3 phase 12 pulse = ripple of 4-10%

3) high frequency = ripple of 3-4% most common and fastest

Front 21

3 types of phase generators

Back 21

1) 3 phase 6 pulse = ripple if 13-25%

2) 3 phase 12 pulse = ripple of 4-10%

3) high frequency = ripple of 3-4% most common and fastest

4) single phase = ripple of 100%

Front 22

Voltage ripple

Back 22

% of max. KV variation in high voltage. Causes variations in X-ray out put.

Front 23

Falling load generator

Back 23

Designed for 3 phase or high frequency.
Shorter exposure time and simple operation. But has shorter tube life ( high mA values= increased filament wear), can't select mA or do breathing techniques

Front 24

Tabletop

Back 24

Weight capacity(400 lbs.), radiolucent ( plastic), scratch resistant and smooth, fixed or tilting, floating or moving, height adjustable

Front 25

Falling load generator

Back 25

Designed for 3 phase or high frequency.
Shorter exposure time and simple operation. But has shorter tube life ( high mA values= increased filament wear), can't select mA or do breathing techniques

Front 26

Tabletop

Back 26

Weight capacity(400 lbs.), radiolucent ( plastic), scratch resistant and smooth, fixed or tilting, floating or moving, height adjustable

Front 27

Tube supports

Back 27

Ceiling tube mount
Floor " "
Mobile
C-arm ( pedestal)
Floor to ceiling

Front 28

Tube components

Back 28

Absolutely need!!
Sources of electrons (Filament)
Target(anode/focal spot)
KV
Vaccum( no air molecules to hit)

Front 29

Protective housing

Back 29

Controls leakage( off focus radiation ) and scatter ( anything X-rays interact with ex. Patient, table...) and isolates high voltage parts
Provides means to cool tube =oil
X-ray tube inside

Front 30

Envelope

Back 30

Encases cathode and anode but not stator
Made of Pyrex
Maintains vacuum
X-rays leave envelope through a window segment

Front 31

Cathode

Back 31

- charge. Made of filament, focusing cup,and wiring. Focuses electron stream towards anode.

Front 32

Cathode

Back 32

- charge. Made of filament, focusing cup,and wiring. Focuses electron stream towards anode.

Front 33

Filament

Back 33

Provides resistance = thermionic cloud(thermionic emission, cloud if electrons around cathode). Made of molybdenum = hard to melt/vaporize.
Usually 2 filaments(dual focus)
1) smaller=increased image detail
2) larger=more hear less detail( penumbra= fuzzy area around image)

Front 34

Anode

Back 34

KV
+ charge
Target surface
Primary thermal conductor Consists of anode, stator and rotor
Conducts high volt. back into circuitry

Front 35

Anode

Back 35

KV
+ charge
Target surface
Primary thermal conductor Consists of anode, stator and rotor
Conducts high volt. back into circuitry

Front 36

Statir

Back 36

Series of electromagnets
Outside envelope( high volt. would destroy magnets)
Magnetic field from electromagnet effect turns rotor

Front 37

Anode

Back 37

KV
+ charge
Target surface
Primary thermal conductor Consists of anode, stator and rotor
Conducts high volt. back into circuitry

Front 38

Statir

Back 38

Series of electromagnets
Outside envelope( high volt. would destroy magnets)
Magnetic field from electromagnet effect turns rotor

Front 39

Rotir

Back 39

Inside envelope (within stator)
Hollow copper cylinder affected by elecmag. Field from stator and causes anode to turn
Moves on silver(lubricant) plated ball bearings

Front 40

Anode

Back 40

KV
+ charge
Target surface
Primary thermal conductor Consists of anode, stator and rotor
Conducts high volt. back into circuitry

Front 41

Statir

Back 41

Series of electromagnets
Outside envelope( high volt. would destroy magnets)
Magnetic field from electromagnet effect turns rotor

Front 42

Rotir

Back 42

Inside envelope (within stator)
Hollow copper cylinder affected by elecmag. Field from stator and causes anode to turn
Moves on silver(lubricant) plated ball bearings

Front 43

Anode disc

Back 43

Focal track= circular path on anode struck by electrons
Target/focal point= WHERE X-RAYS CREATED!!! Where the X-rays hit the focal track

Front 44

Anode

Back 44

KV
+ charge
Target surface
Primary thermal conductor Consists of anode, stator and rotor
Conducts high volt. back into circuitry

Front 45

Statir

Back 45

Series of electromagnets
Outside envelope( high volt. would destroy magnets)
Magnetic field from electromagnet effect turns rotor

Front 46

Rotir

Back 46

Inside envelope (within stator)
Hollow copper cylinder affected by elecmag. Field from stator and causes anode to turn
Moves on silver(lubricant) plated ball bearings

Front 47

Anode disc

Back 47

Focal track= circular path on anode struck by electrons
Target/focal point= WHERE X-RAYS CREATED!!! Where the X-rays hit the focal track

Front 48

Line focus principle

Back 48

Reduce area of focal spot= best resolution of detail while having largest actual focal spot.
Viewing a sloped surface at an angle reduces it's apparent size.

Front 49

Anode

Back 49

KV
+ charge
Target surface
Primary thermal conductor Consists of anode, stator and rotor
Conducts high volt. back into circuitry

Front 50

Statir

Back 50

Series of electromagnets
Outside envelope( high volt. would destroy magnets)
Magnetic field from electromagnet effect turns rotor

Front 51

Rotir

Back 51

Inside envelope (within stator)
Hollow copper cylinder affected by elecmag. Field from stator and causes anode to turn
Moves on silver(lubricant) plated ball bearings

Front 52

Anode disc

Back 52

Focal track= circular path on anode struck by electrons
Target/focal point= WHERE X-RAYS CREATED!!! Where the X-rays hit the focal track

Front 53

Line focus principle

Back 53

Reduce area of focal spot= best resolution of detail while having largest actual focal spot.
Viewing a sloped surface at an angle reduces it's apparent size.

Front 54

Actual Focal spot

Back 54

ACTUAL TARGET/FOCUS POINT= ACTUAL AREA OF ELECTRONS HITTING AND X-RAY CREATION.
Size controlled by filament length.

Front 55

Anode

Back 55

KV
+ charge
Target surface
Primary thermal conductor Consists of anode, stator and rotor
Conducts high volt. back into circuitry

Front 56

Statir

Back 56

Series of electromagnets
Outside envelope( high volt. would destroy magnets)
Magnetic field from electromagnet effect turns rotor

Front 57

Rotir

Back 57

Inside envelope (within stator)
Hollow copper cylinder affected by elecmag. Field from stator and causes anode to turn
Moves on silver(lubricant) plated ball bearings

Front 58

Anode disc

Back 58

Focal track= circular path on anode struck by electrons
Target/focal point= WHERE X-RAYS CREATED!!! Where the X-rays hit the focal track

Front 59

Line focus principle

Back 59

Reduce area of focal spot= best resolution of detail while having largest actual focal spot.
Viewing a sloped surface at an angle reduces it's apparent size.

Front 60

Actual Focal spot

Back 60

ACTUAL TARGET/FOCUS POINT= ACTUAL AREA OF ELECTRONS HITTING AND X-RAY CREATION.
Size controlled by filament length.

Front 61

Effective focal spot

Back 61

Area of focal spot projected out of tube towards IR

Front 62

Anode

Back 62

KV
+ charge
Target surface
Primary thermal conductor Consists of anode, stator and rotor
Conducts high volt. back into circuitry

Front 63

Stator

Back 63

Series of electromagnets
Outside envelope( high volt. would destroy magnets)
Magnetic field from electromagnet effect turns rotor

Front 64

Rotor

Back 64

Inside envelope (within stator)
Hollow copper cylinder affected by elecmag. Field from stator and causes anode to turn
Moves on silver(lubricant) plated ball bearings

Front 65

Anode disc

Back 65

Focal track= circular path on anode struck by electrons
Target/focal point= WHERE X-RAYS CREATED!!! Where the X-rays hit the focal track

Heat management= speed, materials, thickness, warmup procedure

Front 66

Line focus principle

Back 66

Reduce area of focal spot= best resolution of detail while having largest actual focal spot.
Viewing a sloped surface at an angle reduces it's apparent size.

Front 67

Actual Focal spot

Back 67

ACTUAL TARGET/FOCUS POINT= ACTUAL AREA OF ELECTRONS HITTING AND X-RAY CREATION.
Size controlled by FILAMENT length, focusing cup, distance from anode to cathode.

Front 68

Effective focal spot

Back 68

Area of focal spot projected out of tube towards IR. Size affected by actual focal spot and an side target angle.

Front 69

Anode target angle

Back 69

Smaller the target angle = smaller focal spot can be achieved.
Smaller target angles can limit size of beam field at short SIDs.
Less than 45*= effective FS smaller than actual FS

Front 70

Focal spot blooming

Back 70

As mA increases focal spot size increases ( due to # of electrons given off, increased beam size, resulting larger actual and effective focal spot

Front 71

Anode heel effect

Back 71

Radiation intensity is higher at cathode side of tube.
Caused by line focus principle.
More noticeable with lager cassette, shorter SID, steeper anode angles

Front 72

Off focus radiation

Back 72

X-ray photons not produced at the focal spot ( ghost image) not part of the primary beam.

Front 73

3 types of rating charts

Back 73

1) radiographic charts
2) anode cooling charts
3)housing cooling charts

Front 74

Power rating generator

Back 74

Defines max. KV and mA at 0.1sec.

Watts=V * A

Front 75

Heat units (HU)

Back 75

HU=mA*kV*time * rectification constant

Rectification constant = generator type 1 phase=1
3 phase = 1.35
High frequency = 1.4

Front 76

Anode cooling chart

Back 76

Anode storage capacity.
Calculates cooling time between series of exposures. Measured in HU/watt-sec/J

Ex. In single phase how many HU?

If at 100 and doing 4 exposure...

350/100=3 so can't do the 4th exposure

3 exposures at 100 kHU =300 kHU

350-100=250

Would need to cool to 250 to do the 4th exposure.

Front 77

Housing cooling charts

Back 77

Calculates time necessary for housing to cool

Front 78

Tube failure

Back 78

1)Filament thinning/vaporization
So.. Use low mAs, gentle handling of tube, don't ride rotor
2)envelope aging= less photons leaving tube, HVL increase so... Use low mAs and rotor at a minimum
3)focal track aging/damage=pitted, decreased photon output from FS so....low mAs, do warmup, and avoid tube loading limits
4)anode disk warping/cracking= increased FS size and more bearing wear so.... Use tube rating limits, handle tube gently
5)bearings distortion/roughened= motor noise, slow rotor speed so...run rotor at minimum
6) stator/rotor failure
Electrons overheat anode and tungsten drips onto the glass envelope=crack
7) overall failure= exposure over tube limit, not warming up, filament vaporization

Front 79

Warmup procedure

Back 79

'Vacuum pump' to maintain strong vacuum, without warm up can crack anode

Front 80

Attenuation

Back 80

Reduction of the number of X-ray photons in beam and subsequent loss if energy as beam passes through matter

Front 81

5 possible X-ray interactions with matter

Back 81

1) photoelectric absorption ( most important and common)

2)Compton scattering
3)coherent scattering
4) pair production
5)photo disintegration

Front 82

Warmup procedure

Back 82

'Vacuum pump' to maintain strong vacuum, without warm up can crack anode

Front 83

Attenuation

Back 83

Reduction of the number of X-ray photons in beam and subsequent loss if energy as beam passes through matter

Front 84

5 possible X-ray interactions with matter

Back 84

1) photoelectric absorption ( most important and common)

2)Compton scattering
3)coherent scattering
4) pair production
5)photo disintegration

Front 85

Photoelectric absorption

Back 85

1) interaction with inner shell electron ( photon must have higher energy than the binding energy)
2)incident photon ejects the electron and is totally absorbed ( ejected electron called photo-electron)
3)ionized atom
4) vacancy filled by another electron (secondary radiation)(characteristic and cascade radiation)

3 rules 1) incident photon must have energy higher than binding energy of inner shell electron 2) PE interaction more likely if photon energy slightly higher than atom binding energy ( as X-ray energy increases ( increased kV) PE affect decreased) 3) more likely to occur with high atomic numbers ex. Bone and barium

1-2mm of tissue absorption

Front 86

Warmup procedure

Back 86

'Vacuum pump' to maintain strong vacuum, without warm up can crack anode

Front 87

Attenuation

Back 87

Reduction of the number of X-ray photons in beam and subsequent loss if energy as beam passes through matter

Front 88

5 possible X-ray interactions with matter

Back 88

1) photoelectric absorption ( most important and common)

2)Compton scattering
3)coherent scattering
4) pair production
5)photo disintegration

Front 89

Photoelectric absorption

Back 89

1) interaction with inner shell electron ( photon must have higher energy than the binding energy)
2)incident photon ejects the electron and is totally absorbed ( ejected electron called photo-electron)
3)ionized atom
4) vacancy filled by another electron (secondary radiation)(characteristic and cascade radiation)

3 rules 1) incident photon must have energy higher than binding energy of inner shell electron 2) PE interaction more likely if photon energy slightly higher than atom binding energy ( as X-ray energy increases ( increased kV) PE affect decreased) 3) more likely to occur with high atomic numbers ex. Bone and barium

1-2mm of tissue absorption

Front 90

K-edge

Back 90

When incident X-ray photon overcomes binding energy of atoms k shell (inner)
= increases PE effect, increased X-ray absorption and ionization

Front 91

Warmup procedure

Back 91

'Vacuum pump' to maintain strong vacuum, without warm up can crack anode

Front 92

Attenuation

Back 92

Reduction of the number of X-ray photons in beam and subsequent loss if energy as beam passes through matter

Front 93

5 possible X-ray interactions with matter

Back 93

1) photoelectric absorption ( most important and common)

2)Compton scattering
3)coherent scattering
4) pair production
5)photo disintegration

Front 94

Photoelectric absorption

Back 94

1) interaction with inner shell electron ( photon must have higher energy than the binding energy)
2)incident photon ejects the electron and is totally absorbed ( ejected electron called photo-electron)
3)ionized atom
4) vacancy filled by another electron (secondary radiation)(characteristic and cascade radiation)

3 rules 1) incident photon must have energy higher than binding energy of inner shell electron 2) PE interaction more likely if photon energy slightly higher than atom binding energy ( as X-ray energy increases ( increased kV) PE affect decreased) 3) more likely to occur with high atomic numbers ex. Bone and barium

1-2mm of tissue absorption

Front 95

K-edge

Back 95

When incident X-ray photon overcomes binding energy of atoms k shell (inner)
= increases PE effect, increased X-ray absorption and ionization

Front 96

Compton scattering

Back 96

1)Photon interacts with loose outer shell electron
2)removes electron ( Compton/recoil electron)
3)photon proceeds in different direction
4)photon less energy once scattered
5) continues to scatter until absorbed

Occurs more at high kV= more scatter
'Noise' on IR/ quantum mottle

Pose a radiation hazard to pt and tech

Front 97

Warmup procedure

Back 97

'Vacuum pump' to maintain strong vacuum, without warm up can crack anode

Front 98

Attenuation

Back 98

Loss of photons from moving through matter

Caused by scatter and absorption

Front 99

5 possible X-ray interactions with matter

Back 99

1) photoelectric absorption ( most important and common)

2)Compton scattering
3)coherent scattering
4) pair production
5)photo disintegration

Front 100

Photoelectric absorption

Back 100

1) interaction with inner shell electron ( photon must have higher energy than the binding energy)
2)incident photon ejects the electron and is totally absorbed ( ejected electron called photo-electron)
3)ionized atom
4) vacancy filled by another electron (secondary radiation)(characteristic and cascade radiation)

3 rules 1) incident photon must have energy higher than binding energy of inner shell electron 2) PE interaction more likely if photon energy slightly higher than atom binding energy ( as X-ray energy increases ( increased kV) PE affect decreased) 3) more likely to occur with high atomic numbers ex. Bone and barium

1-2mm of tissue absorption

Front 101

K-edge

Back 101

When incident X-ray photon overcomes binding energy of atoms k shell (inner)
= increases PE effect, increased X-ray absorption and ionization

Front 102

Compton scattering

Back 102

1)Photon interacts with loose outer shell electron
2)removes electron ( Compton/recoil electron)
3)photon proceeds in different direction
4)photon less energy once scattered
5) continues to scatter until absorbed

Occurs more at high kV= more scatter
'Noise' on IR/ quantum mottle

Pose a radiation hazard to pt and tech

Front 103

SID to IR intensity

Back 103

Inverse squared
I1/I2 = (D2)2 / (D1)2

More SID=more pt dose