Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Rad Imaging/Protection Ch. 3 & 4 > Ch. 3-4 > Flashcards

Ch. 3-4 Flashcards

1
Q

What does kVp control

A

QUALITY, or penetrating power

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Name 3 ways X-Rays interact with human tissue

A
  1. Interact with the atoms of the patient and become ABSORBED
  2. Intersect with the atoms of the patient and become SCATTERED
  3. Pass through the patient WITHOUT interaction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

More Absorption =

A

Greater possibility of biological damage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Primary Radiation

A

What exits the tube

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Anode

A

Target

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Reasons tungsten/rhenium are used as target materials

A

High melting points
High atomic numbers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Inherent Filtration

A

Built-In

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Added Filtration

A

A certain thickness of added ALUMINUM to “harden” the beam within the collimator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Combo of X-Ray tube glass wall and added aluminum placed within the collimator may be called

A

Permanent Inherent Filtration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Primary Radiation happens (before/after) it has gone through filtration

A

AFTER

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

SINGLE PHASE

A

100% voltage ripple

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

3 phase (6 pulse)

A

13% voltage ripple

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

3 phase (12 pulse)

A

4% voltage ripple

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

High Frequency

A

1% voltage ripple

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Do all photons in a X-Ray beam have the same energy

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The energy of the average photon is about 1/3 of the energy of the most energetic photon

A

Example:
100 kVp beam contains photons having energies of 100 KeV or less, with an average energy of approximately 33 KeV
100 divided by 1/3=33

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Can the most energetic X-Ray photon have more energy than the set kVp

A

No, the photons can have no more energy than the set kVp

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Photons that travel through the patient without interacting & reach the image receptor

A

Direct Transmission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

(Possible/Impossible) to predict with certainty what will happen to a single photon when it enters human tissue

A

IMPOSSIBLE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

(Possible/Impossible) to predict what will happen on the average when a large number of photons enter the human body

A

POSSIBLE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Absorbed Dose

A

D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Coherent Scattering

A

Occurs with low-energy photons, less than 10 KeV (kVp’s 1-50)
Wavelengths of incident and scattered are the same, so no new energy is absorbed by the atom, because no kinetic energy is lost
Small angle scatter
May result in small amounts of fog

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Photoelectric Absorption

A

Interaction of a X-Ray PHOTON and an INNER SHELL ELECTRON
Involves ejection of an inner shell electron
Vacancy of inner shell is filled by an outer orbital shell electron
A difference in binding energies between the two electron shells forms a second photon
Photoelectron created ^
IMPORTANT MODE OF INTERACTION FOR PRODUCING USEFUL IMAGES

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

PHOTOELECTRIC ABSORPTION/Auger Effect

A

When an inner electron is removed (inner-shell vacancy) the energy given off by another electron filling his void can go on to eject another electron in the same atom
Instead of filling the “hole” , it ejects another electron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Probability of photoelectric absorption depends on
Energy (E) of the incident photons Atomic number (Z) of the atoms comprising the body part
26
Energy of the incident photon decreases as
kVp decreases
27
Bone Atomic #
13.8
28
Soft Tissue Atomic #
7.4
29
Air Atomic #
7.6
30
Absorption vs kVp As kVp decreases
Absorption increases
31
The whiter areas on radiographs
The higher the absorption (Bone, Lead, Medal, Barium, ETC)
32
(Darker/Whiter) Less attenuation by the body part
Darker
33
(Darker/Whiter) More attenuation by the body part
Whiter Ex: Knee replacements show up really bright because they absorb more
34
Increase window level =
Brighter, white, increased brightness
35
Decreased window level =
Darker, black, decreased brightness
36
Use of positive contrast medium- Iodine/Barium
Appears lighter because it increases photoelectric effect
37
Use of negative contrast medium-Air
Appears darker
38
Compton Scattering
Interaction with a loosely bound outer shell electron X-Ray photon dislodges the electron from its outer shell, ionizing the atom The freed electron is able to ionize other atoms and bounces around unit it finds an atom in need of another electron The incident X-Ray photon that kicked out the electron continues on its way but in a new direction Very Bad- Degrades image ‼️
39
Compton scattering scatter type
All-Directional scatter
40
Pair Production
Occurs when a high-energy photon interacts with the NUCLEUS of an atom The photon disappears and the energy is converted into a NEGATRON (ordinary electron) and a POSITRON (positively charged electron) Positron and electron will annihilate each other
41
Examples of unstable nucleus in PET
Fluorine-18 Carbon-11 Nitrogen-13
42
WHAT DOES PET SCANNING DO Ibuprofen
Reveals how tissues and organs are functioning Utilizes a radioactive drug Used a radioactive drug- may be injected, swallowed, inhaled depending on study Collects in areas of body that have higher levels of chemical activity , showing up as “bright spots”
43
Photodisintegration
Interaction that occurs at more than 10 MeV (3,000 kVp) High energy photon is absorbed by a nucleus; completely destroying nucleus
44
Higher mA=
Higher number of electrons being produced
45
<5 rad
No immediate observable effects
46
~5 to 50 rad
Slight blood changes
47
~50 to 150 rad
Slight blood changes Symptoms of nausea, fatigue, vomiting, etc..
48
~150 to 1,110 rad
Severe blood changes Could die within two weeks Infection likely May need a bone marrow transplant
49
~1,100 to 2,000 rad
The probability of death increases 100% within one to two weeks Symptoms are immediate Gastrointestinal system is destroyed Once GI System ceases to function, nothing can be done, care for comfort only
50
>2,000 rad
Death Central Nervous System can no longer control anything including breathing and blood circulation Nothing can be done, care for comfort only
51
When were X-Rays discovered
November 8, 1895
52
Somatic Damage
Result of excessive occupational radiation exposure for early pioneers and excessive exposure of patients Cancer Blood Disorders
53
Unit used from 1900 to 1930 to measure radiation exposure
Skin Erythema Dose
54
Was the Skin Erythema Dose accurate?
No Tammy; “It’s like being out in the sun until you get a sunburn and then determining that you shouldn’t be in the sun that long or you will burn” Everybody’s different
55
SECOND INTERNATIONAL CONGRESS OF RADIOLOGY 1928 (The first was unable to make any decisions about the measuring effects of radiation) 1925
Acceptance of Roentgen (R)
56
Early Tissue Radiation Reactions
Nausea Fatigue Loss of hair Fever Blood disorders
57
Late Tissue Radiation Reactions
Cataracts Reduced fertility Sterility Organ Atrophy (decrease in size due to cell shrinkage)
58
Stochastic-Probabilistic
Mutational or randomly occurring biological changes, INDEPENDENT OF DOSE
59
Stochastic effects
Cancer Genetic effects
60
When does ROENTGEN become internationally accepted
1937
61
1934- committee recommendations of what daily limit dose
.2 roentgen 83x higher than what it is today‼️
62
1936-committee recommendations of what daily limit dose
.1 roentgen 40x higher than what it is today
63
Max permissible dose (MPD) replaces tolerance dose for radiation protection purposes When?
Early 1950s
64
When is (R) redefined to increase accuracy and acceptability
1962
65
Is tolerance dose still accepted
No NO DOSE IS SAFE‼️
66
INTERNATIONAL COMMISSION ON RADIATION UNITS AND MEASURES (ICRU) What did they adopt and when?
Adopted SI units for use with ionizing radiation in 1980
67
National Council on Radiation Protection (NCRP) What did they adopt and when?
Adopted SI units for use in 1985
68
International Commission on Radiological Protection What did they adopt and when?
Adopted the term EFFECTIVE DOSE in 1991 ✅
69
Exposure
Radiation quantity that expresses the concentration of radiation delivered to a specific area, such as the surface of the human body
70
Precise Measurements of Radiation Exposure
Total amount of ionization a X-Ray beam produces in a known mass of air Accomplished in a lab by using an ionization chamber
71
Ampere
SI unit of electrical charge
72
Air Kerma
SI quantity used to express how energy is transferred from a beam of radiation to a material (patient’s skin) Can be used to express X-Ray tube output and inputs to image receptors ❗️K❗️inetic ❗️E❗️nergy ❗️R❗️eleased PER UNIT ❗️MA❗️ss
73
Unit used to measure the quantity of air kerma
Gray (Gy)
74
Air Kerma
Metric units of JOULE (energy) per kilogram (J/kg) May be stated in Gy
75
When Gy is used to indication kinetic radiation energy absorbed in a MASS OF AIR, it is written as (X-Ray Tube Output)
GYa AIR-a
76
When the Gy is used to indicate kinetic radiation energy absorbed in a MASS OF TISSUE, it is written as (Transmitted X-Rays absorbed)
GYt Tissue-t
77
Dose Area Product (DAP)
Sum total of air kerma over the exposed area of the patients surface or, a measure of the amount of radiant energy that has been thrust into a portion of the patients body surface Specified in units of nagy-cm2 Example: Air kerma dose of 20mGy Surface area exposed is 100cm2 DAP; 20mGy X 100cm2=2,000mGy/cm2
78
What’s Absorbed Dose responsible for
Any biological damage resulting from exposure of the tissues to radiation
79
X-Ray Photon, Beta, Gamma quality factor
1
80
Thermal Neutron Quality Factor
5
81
Fast neutron quality factor
20
82
Low energy internal protons, Alpha particles, Multiple charged particles of unknown energy quality factor
20
83
High energy external protons quality factor
1
84
EqD
Product of the average absorbed dose in a tissue or organ in the body and it’s associated with awe chosen for the type and energy of the radiation in question
85
Biological effects may be determined and expressed in..
Sv
86
EqD=
D X Wr
87
Sv=
Gy X Wr
88
Radiation Weighting Factor (Wr)
Must be used when determining EqD Used for radiation protection purposes to account for differences in biological impact among various types of ionizing radiation Places risks associated with biological effects on a common scale
89
Annual Whole Dose Limits General Public
1mSv
90
EfD
Measure of the overall risk of exposure to humans from ionizing radiation Both the effect of type of radiation and the variability in radio-sensitivity of the part
91
EfD=
D X Wr X Wt
92
mSv to mrem
X100
93
Collective EfD
Used in radiation protection to describe internal and external dose measurements Quantity used to describe exposure of a POPULATION OR GROUP Person-Sievert
94
Total Effective Dose Equivalent (TEDE)
Radiation dosimetry quantity that was defined by the NRC to monitor and control human exposure to ionizing radiation
95
TEDE
Designed to take in account ALL possible sources of radiation exposure

Rad Imaging/Protection Ch. 3 & 4 (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions