X-Ray Interaction With Matter

Front 1

X-ray Interactions with Matter ((test))

What are the 5 different interactions with matter?

Back 1

1. Classical scattering

2. Compton Effect

3. Photoelectric Effect

4. Pair production

5. Photodisintegration

Front 2

Classical Scattering ((test))

Give the 3 names it is known as?

Back 2

1. Coherent

2. Thompson

3. Rayleigh scattering

Front 3

Classical Scattering ((test))

What type of energy is produced?

Back 3

Low

Front 4

Classical Scattering ((test))

Classical Scatter produce low- energy x-ray photons. How many kev is used?

Back 4

Below 10 kev

Front 5

Classical Scattering ((test))

Incident x-rays and scattered x-rays have equal?

Back 5

Wavelength and Energy

Front 6

Classical Scattering ((test))

As an incident x-ray slightly changes direction without changing it's energy, what type of x-ray will occur?

Back 6

Scattered x-ray occurs

Front 7

Classical Scattering

What happens in a Classical Scattering?

Back 7

1. Incident x-ray interacts with target atom

2. Incident x-ray changes direction without change in energy

3. Scattered x-ray occur

Front 8

Compton Effect

Give the 2 different names it is known as?

Back 8

1. Compton scattering

2. Modified scatter

Front 9

Compton Effect ((test))

Define Compton effect?

Back 9

Incident x-rays interact with outer shell electron, ejecting it from the atom and ionizing the atom causing the photon to change direction with less energy.

Front 10

Compton Effect

What is the ejected electron known as? Give 2 names...

Back 10

1. Secondary electron

2. Compton electron

Front 11

Compton Effect

The energy of a scattered x-ray equal to the difference between energies of ?

Back 11

Difference between the energy of incident x-rays and energy of ejected electron

Front 12

Compton Effect

Can be transmitted through the body, absorbed, scattered out of the body, what type of effect is this?

Back 12

Compton effect

Front 13

Compton Effect

The energy of ejected electron equal to?

Back 13

It's binding energy plus kinetic energy when leaving the atom.

Front 14

Compton Effect

Usually the scattered x-ray retains most of its energy. How much of it's original energy?

Back 14

Two thirds its original energy

Front 15

Compton Effect

Define Back scatter radiation

Back 15

X-rays that have interact with object and deflected backwards.

Front 16

Compton Effect

What is the probability of Compton effect dealing with energy?

Back 16

Decrease as energy increases because increase in penetration through tissue without interaction.

Front 17

Compton Effect

What is the probability of Compton effect related to?

Back 17

Photoelectric effect

Front 18

Compton Effect

What is the probability of a Compton effect if there is higher energy?

Back 18

Low Compton effect

Front 19

Compton Effect

What is the probability of Compton effect with atomic number?

Back 19

Compton effect is NOT dependent on atomic number.

Front 20

Compton Effect

How are x-ray effected with the probability of soft tissue or bone?

Back 20

Any x-rays is the same as soft tissue or bone because it is not dependent on atomic number.

Front 21

Photoelectric Effect (test)

What happens in Photoelectric effect?

Back 21

Incident x-ray interact with inner shell electron,and ionizes the atom. Ejects a photo-electron, but the x-ray is absorbed and not scattered.

Front 22

Photoelectric Effect ((test))

What do the photo-electrons kinetic energy equal to the difference between the energy of ?

Back 22

The difference between the energy of incident x-ray and binding energy of electron.

Front 23

Photoelectric Effect ((test))

What happens to the photoelectron?

Back 23

Electron is ejected from k-shell, an outer-shell electron will drop into the vacancy and emit a characteristic x-ray.

Front 24

Photoelectric Effect

How will a secondary radiation behave?

Back 24

Like scatter radiation

Front 25

Photoelectric Effect ((test))

What does a secondary radiation contribute to an x-ray image?

Back 25

Nothing useful to x-ray image.

Front 26

Photoelectric Effect

A photoelectric interaction cannot occur unless?

Back 26

Incident x-ray had energy equal or greater than electrons binding energy.

Front 27

What do a characteristic radiation and photoelectric effect have in common?

((test))

Back 27

Interact with inner shell electron

Front 28

In the photoelectric effect, what does it do in the body?

Back 28

Absorbs

Front 29

Photoelectric effect

The probability of an x-ray that will undergo photoelectric interaction depends on what 2 things?

Back 29

1. x-ray energy

2. Atomic number

Front 30

Photoelectric effect

Energy:

The probability of photoelectric interaction is inversely or directly proportional to the third power of the x-ray energy?

Back 30

Inversely

Front 31

Photoelectric effect

Atomic number:

What is the probability of a photoelectric interaction is inversely or directly proportional to the third power of the atomic number of the absorbing material.

Back 31

Directly

Front 32

Photoelectric Effect

What is the probability of energy if there is a increase in kVp? List 2 things it will effect?

Back 32

Increase kVp=

1. Decrease x-ray energy

2. Less photoelectric effect

Front 33

Photoelectric Effect

What is the probability of energy if there is a decrease in kVp? List 3 things it will effect.

Back 33

Decrease kVp=

1. Increase x-ray energy

2. More x-rays absorb

3. More photoelectric effect

Front 34

Photoelectric Effect

What is the probability the atomic number of a photoelectric effect if there is an increase, what will happen to the atomic number?

Back 34

Increase in atomic number

Front 35

Photoelectric Effect

What is the probability of an atomic number if atoms with high atomic number will absorb______ x-rays?

Back 35

More x-rays

Front 36

Photoelectric Effect

Why bone absorbs more x-rays than soft tissue?

Back 36

Bone has high atomic number

Front 37

Pair Production

When does a pair production occur?

Back 37

Incident x-rays interact with field of the nucleus

Front 38

Pair Production

What happens in pair production?

Back 38

Interaction between x-ray and nucleus which causes the x-ray to disappear. In its place 2 electrons appear.

Front 39

Pair Production

Incident photon must have Mega Electron Volts (MEV) of energy of?

Back 39

1.02 MeV

Front 40

Photodisintegration

When does photodisintegration occur?

Back 40

Occurs when extremely high energy (10 MeV) is absorbed by the nucleus.

Front 41

Photodisintegration

What will happen to the nucleus?

Back 41

Nucleus is raised to an excited state and instantaneously emits a nucleon or other nuclear fragments.

Front 42

What interactions can happen?

Name 3 things x-rays can do? ((test))

Back 42

1. Absorbed- Photoelectric

2. Scattered- Compton scatter

3. Transmitted- Patient to image receptor

Front 43

A useful beam equals to the differences between...? ((test))

Back 43

Equal to the differences between absorbed photoelectrically and those transmitted

Front 44

Differential Absorption ((test))

List the things that give you differential absorption.

What are the 3 different absorption?

Back 44

1. Compton scattering

2. Photoelectric effect

3. X-ray transmitted through patient

Front 45

What will give you a diagnostic film?

Back 45

Transmitted or Scattered

Front 46

What will give you a useful beam?

Back 46

Transmitted or Scattered

Front 47

Differential Absorption ((test))

Define differential absroption?

Back 47

X-ray image results from difference between x-rays absorb photoelectrically in patient and those x-rays transmitted to image receptor.

Front 48

Differential Absorption ((test))

What happens in a photoelectric effect when anatomic structures that absorb the x-ray?

Back 48

Radiopaque (Useful information/ white image)

Front 49

Differential Absorption

Anatomic structures that transmit x-rays equal what type of image?

Back 49

Radiolucent

Front 50

Differential Absorption

In differential absorption an x-ray image results from what 2 things?

Back 50

X-rays absorbed photoelectrically in patient and x-rays transmitted to image receptor.

Front 51

Differential Absorption

Difference in x-ray interaction equal to?

Back 51

Differential absorption

Front 52

Differential Absorption

Differential absorption in bone and soft tissue equal to?

Back 52

Equal to Photoelectric interactions, which depends greatly on atomic number.

Front 53

Differential Absorption

To achieve optical difference absorption, what must you do?

Back 53

You must have proper kVp selection.

Front 54

Depending on Atomic Number

Low energies most x-ray interactions equal to?

Back 54

Photoelectric

Front 55

Depending on Atomic Number

High energies most x-ray interactions equal to?

Back 55

Compton

Front 56

Depending on Atomic Number

Increase in energy will increase or decrease the chances of interactions?

Back 56

Decrease chances of interactions

Front 57

Depending on Atomic Number

Small images difference in what 2 things?

Back 57

1. Soft tissue-Ex: Mammography

2. Low kVp- Results in maximum differential absorption.

Front 58

Depending on Atomic Number

Example:

How much more likely is an x-ray to interact with soft tissue than bone?

Bone: 13.8

Soft tissue: 7.4

Back 58

Bone: (13.8)^3

Soft tissue: (7.4)^3

2628 Bone / 405 Soft tissue

= 6.5 interaction

Front 59

Dependence of Mass Density (test)

What is mass density?

Back 59

Quality of matter per unit volume (kg/m^3) OR (gm/cm^3).

Front 60

Dependence of Mass Density

What is it related to?

Back 60

Related to mass of each atom

Front 61

Dependence of Mass Density

What does it tell?

Back 61

How tightly the atoms are packed together

Front 62

Dependence of Mass Density

Which has a higher mass density, bone or soft tissue?

Back 62

Bone

Front 63

Dependence of Mass Density

Interactions between x-rays and tissue being imaged is directly or indirectly proportional to the mass density of the tissue.

Back 63

Directly proportional to the mass density of the tissue

Front 64

Contrast Examination

Define Contrast Agent?

Back 64

A compound used as an aid for imaging internal organs with x-rays.

Front 65

Contrast Examination

Why must the contrast medias need to have a high atomic numbers?

Back 65

So that differential absorption to occur.

Front 66

Double Contrast Examinations ((test))

Why do you do this?

Back 66

Exam for the colon that uses Air and Barium for contrast.

Front 67

Single Contrast Examination

Why do you do this?

Back 67

Single contrast Barium Enema

Front 68

Exponential Attenuation

What is it?

Back 68

Relative frequency of interaction of each mechanism depends primarily on the atomic number of those atoms and x-rays energy.

Front 69

Exponential Attenuation

What is Attenuation?

Back 69

Total reduction in number of x-rays remaining in x-ray beam after penetration through a given thickness of tissue.

Front 70

Exponential Attenuation

What does attenuation equal to?

Back 70

Absorption + Scattering.

Front 71

Exponential Attenuation

Absorption is what type of interaction?

Back 71

All-or Nothing interaction

Front 72

Exponential Radiation

Define Remnant Radiation?

Back 72

Beam that exits tissue and interacts with film or IR.

Front 73

Radiation Protection: Shielding

When should shielding be used? Name 4.

Back 73

1. Patient is child- bearing years

2. When gonads lie in or near useful beam

3. As long as it will not interfere with x-ray taken

4. It is is requested by the patient

Front 74

Occupational Exposure

Define?

Back 74

Dose received by any individual in the course of employment.

Front 75

Occupational Exposure

Where can techs. get the most exposure? Name 6.

Back 75

1. Portables

2. Fluroscopy

3. C- arm surgery

4. Fluroscopy in department

5. Angiography

6. Cardiac Cath lab

Front 76

Occupational Exposure

Where can rads and personnel get less exposure? Name 2.

Back 76

1. Tube under table

2. C- arm tube under table

Front 77

Occupational Exposure

If you are helping in fluroscopy , what kind of gloves may you use?

Back 77

Lead gloves