Radiation Biology

Front 1

Name the 3 principal parts of an atom

Back 1

proton neutron and electron

Front 2

Know where each of the following are located in the atom

1. neutron

2. proton

3. electron

Back 2

1. nucleus

2. nucleus

3. orbit the nucleus in shells or orbits

Front 3

Know the charge of each of the following

1. neutron

2. proton

3. electron

Back 3

1. no charge

2. positive charge

3. negative charge

Front 4

Know what particles must be equal for an atom to be in its most stable state

Back 4

protons and electrons

Front 5

Orbiting electrons are bound to the nucleus by a force of attraction

Back 5

binding energy

Front 6

The closer the electrons orbit to the nucleus the tighter it is bound which does what to the binding energy

Back 6

Higher binding energy

Front 7

Know which shell/orbit has the highest binding energy

Back 7

K shell

Front 8

Energy that corresponds to what orbit the electron is in

Back 8

Energy State

Front 9

Which shell/orbit has the greatest energy

Back 9

outer shell

Front 10

Know how many electrons the following shells/orbits may contain

1. K

2. L

3. M

4. N

5. O

6.P

Back 10

1. K= 2

2. L= 8

3. M= 18

4. N =32

5. O = 50

6. P = 72

Front 11

What is the equation to determine the number electons in a shell or orbit

Back 11

2n^2

Front 12

5 interactions that are possible between ionizing radiation photons and tissue atoms within the patient

Back 12

1. Coherent or unmodified scatter (classical)

2. Compton or modified scattering

3. Photoelectric or Photoelectric absorption

4. Pair Production

5. Photodisintegration

Front 13

3 possible interactions between ionizing radiation and tissues which occur at energies within the diagnostic range of 20 to 150 kVp

Back 13

1. Coherent or unmodified

2. Compton or modified

3. Photoelectric or photoelectric absorption

Front 14

Name the two primary types of interaction that occur betweem xray photons and tissue in the diagnostic xray range of energeries (70kVp and above)

Back 14

1. Compton scattering

2. photelectric absoption

Front 15

Know which interactions take place outside the diagnostic xray range

Back 15

1. Pair production

2. Photodisintegration

Front 16

Know which electron shell the incoming photon/incident photon interacts within the photoelectric interaction

Back 16

inner shell electron

Front 17

Occurs when an incident xray photon interacts with an inner shell electron of an atom. The x-ray photon knocks an inner shell electron out of orbit, which causes the atom to ionize. The electron that is ejected from the inner shell is now called a _______

Back 17

Photoelectric Interaction

ejected inner shell electron-photoelectron

Front 18

Know how photon energy affects the per cent of photoelectric intereaction

Back 18

Lower energy/kVp equals greater percent of photoelectric interaction

Front 19

Know how the atomic number affects the percent of photoelectric interactions

Back 19

higher atomic number = greater % of photoelectric interactions

(ex. bone greater than soft tissue)

Front 20

Know how much of the incident photon's energy in the photoelectric interaction is lost when it interacts with an orbital electron

Back 20

all of its energy

Front 21

Electron ejected from the inner shell

Back 21

photoelectron

Front 22

Low energry x-rays that are emitted by the patient

Back 22

Characteristic radiation

Front 23

Know another name for characteristic radiation

Back 23

Secondary Radiation

Front 24

Know why the emitted photon is called a characteristic photon during a photoelectric interaction

Back 24

Because it's energy is characteristic of the difference between energies of the two shells the electron dropped between

Front 25

Know which interaction contributes to significantly to patient dose and explain why

Back 25

Photoelectric because incident photon is totally or completely absorbed

Front 26

Know which scale of contrast (Gray scale) the photoelectric interaction generally produces

Back 26

short gray scale

lower kVp and higher contrast

Front 27

Know another name for the Compton interaction

Back 27

modified scattering

Front 28

Know which electron shell the incoming photon interacts with in a compton interaction

Back 28

outer shell electrons

Front 29

Know if the incoming photon loses all or only part of its energy in a Compton Interaction

Back 29

Part of its energy

Front 30

List two names for the electron removed from the orbit in a Compton Interaction

Back 30

Compton or recoil electron

Front 31

Know what happens to the ejected electron in both the Photoelectric and Compton Interaction

Back 31

Loses all of its kinetic energy through ionization and exicitation and drops into a vacancy in an electron shell previously created by some ionizing event

Front 32

Know how photon energy affects the Compton interaction

Back 32

higher photon energy (higher kVp) = more likely compton interaction

Front 33

Know how the atomic number affects the compton interaction

Back 33

lower atomic number = more likely for compton interaction

Front 34

Know which interaction is mainly responsible for the radiation that exits the patient and may fog the radiographic image

Back 34

Compton interaction or Compton scattering

Front 35

Know which interaction contributes signficantly to the exposure of a radiographer

Back 35

Compton

Front 36

Know which scale of contrast (Gray scale) the Comton interaction mainly produces

Back 36

Long gray scale

Front 37

Know which interaction results in no ionization of the atom

Back 37

Coherent

Front 38

List another name for Coherent Scatter

Back 38

Classical, Thompson, Rayleigh, or unmodified scatter

Front 39

Interaction at low x-ray energies. Interaction b/w x-ray photons and matter in which no ionzation or lose of energy occurs

Back 39

Coherent Scatter

Front 40

X-ray photons are absorbed by the orbital electron and immediately released in a new direction

Back 40

Coherent Scatter

Front 41

Different degrees of absorption in different tissues that result in the image contrast (gray-scale) and formation of the x-ray image

Back 41

Differential absorption

Front 42

Know how kVp affects differential absorption

Back 42

differential absorption increases; as kVp decreases

Front 43

Name three patient variables that affect the quality of an x-ray beam

Back 43

part thickness, atomic number, or tissue density

Front 44

Know how part thickness affects signal intensity to the image receptor and the quality of an x-ray beam

Back 44

Increased part thickness= decreased signal intensity, and increased compton interactions

Front 45

Number of protons in the nucleus of an atom or Z number

Back 45

Atomic number

Front 46

Know how atomic number affects the absorption of the x-ray beam

Back 46

Increased atomic number = increase in the absorption of the x-ray beam(shorter scale)

Front 47

Know the most common interaction that occurs between x-rays and contrast media placed inside a patients body

Back 47

Photoelectric interaction

Front 48

Name a negative contrast media

Back 48

air

Front 49

Name a positive contrast media

Back 49

barium or iodinated contrast media

Front 50

Name the four major tissues in the human body

Back 50

bone, muscle, air, fat

Front 51

Know which of the four major body tissues has the highest effective atomic number

Back 51

bone

Front 52

Know which interaction occurs most often between x-rays and bone tissue

Back 52

photoelectric interaction

Front 53

Know which interaction occurs most often between xrays and muscle

Back 53

Compton

Front 54

Know which interaction occurs most between x-rays and adipose tissue

Back 54

Compton

Front 55

Know the most common interaction that occurs between x-rays and a metal prosthesis surgically placed inside a patient's body

Back 55

Photoelectric

Front 56

Which particle has the smallest mass and which has the largest

Back 56

smallest =electron

largest= neutron

Front 57

The orbits correspond to energy levels and electrons can only move between levels when they ______ or ______ just the right amount of energy

Back 57

absorb or release

Front 58

The energy is absorbed or released in the form of __________ _________, the frequency of which depends on the difference in energy between the two levels

Back 58

electromagnetic radiation

Front 59

In a stable state how are the shells filled

Back 59

from the nucleus outward

Front 60

To ionize an atom, the x-ray must have _____ equal to or greater than the ______ ______ of the electrons with which it interacts

Back 60

energy

binding energy

Front 61

This requires that each outer shell electron expend energy to occupy a shell closer to the nucleus. The excess energy is in the form of an x-ray photon. This process occurs regardless of whether the atom is in the x-ray tube or the human body

Back 61

NO ANSWER

Front 62

At what energies will pair production and photdisintegration occur and are used only in

Back 62

1.02mEv - 10 mEv

Radiation Therapy

Nuclear Medicine

Positron Emission Tomography (PET)

Front 63

As kVp increases what happens to the probability of photoelectric absorption

Back 63

decreases; due to it is less likely to be absorbed by the body

Front 64

When the electron is knocked out of orbit, an outer shell electron falls down to take its place and emits a very weak x-ray. So in effect, the patient emits an x-ray for a very short time, although the radiation rarely makes it outside of the body

Back 64

NO ANSWER

Front 65

The x-ray (Scattered x-ray) continues in a different direction with less energy

what is the wavelength, frequency and penetrating power like

Back 65

longer wavelength, lower frequency, and less penetrating

Front 66

What usually retains most of the energy of the incident photon

Back 66

scattered x-ray

Front 67

Comptom scattered x-rays can be deflected in any direction; however, the least amount of scattered radiation takes place at _____ from the scattering object (patient

Back 67

90 degrees

Front 68

The Compton electron loses all of its kinetic energy through ionization and excitation and drops into a vacancy in an electron shell previously created by some ionizing event

Back 68

NO ANSWER

Front 69

transfers enough energy to an orbital electron to displace it further away from the nucleus

Back 69

Excitation

Front 70

Electron is removed from the atom

Back 70

Ionization

Front 71

Is CR or DR more affected by scattered radiation

Back 71

CR

Front 72

A Compton interaction may cause a

Back 72

Photoelectric interaction

Front 73

Why does differential absorption occur

Back 73

because of the Photoelectric effect, Compton Scattering, and x-rays transmitted through the patient

Front 74

4 Factors that affect differential absorption

Back 74

kVp

Part thickness

Atomic Number

Tissue Density

Front 75

The chance that an incident x-ray will strike an inner shell orbiting electron increases greatly when the number of inner shell electrons _______

Back 75

increase

Front 76

Due to air being easy to penetrate what happens with photoelectric absorption

Back 76

it decreases

Front 77

Bone has the greatest tissue density which means that bone attenuates x-rays more than any of the other tissues found in the body

Back 77

NO ANSWER

Front 78

Air tissue density is much, more lower than muscle or fat. Therefore, this very, very low tissue density means that air absorbs virtually none of the x-ray beam making that area very black

Back 78

NO ANSWER

Front 79

the reduction in intensity of an x-ray beam as it passes through an object due to the absorption and scattering of photons.

Back 79

Attenuation

Front 80

QUALITY of the x-ray beam produced

Back 80

kVp

Front 81

Quantity of the x-ray beam produced

Back 81

mAs