Saia Unit 3 Flashcards
(143 cards)
1
Q
the 3 cardinal rules for xray:
A
time, distance, shielding
2
Q
inverse square law:
A
I1/I2=D2^2/D1^2
3
Q
primary protective barrier:
A
direct impact, 1/16” lead or equivelent; 7 feet high
4
Q
secondary protective barrier:
A
scatter/leakage, 1/32” lead equivelent
5
Q
xray must scatterat least:
A
2 times before hitting the control booth
6
Q
protective tube housing enclosed by lead lined metal covering:
A
1/16 lead, reduces leakage
7
Q
leakage from the tube housing should exceed:
A
100mR/hr at 1 meter
8
Q
time of occupancy factor:
A
amount of time an area is ossupied and by whom
9
Q
workload:
A
radiation activity level (max kvp and max mas)
10
Q
Use:
A
the amount of time xray is “on” during the day
11
Q
Lead underwear keep radiation and are used for:
A
brachytherapy of the prostate
12
Q
mobile unit switch
A
should allow tech to obtain at least a distance of 6’ from patient
13
Q
fluoroscopy drapes and bucky slot cover should have a minimum:
A
.25mm pb/eq
14
Q
fluoroscopy deadman switch:
A
only emits radiation when constant pressure is applied
15
Q
c-arm source to tabletop must not be less than:
A
12”
16
Q
source to tabletop for fixed fluoro unit must not be less than:
A
15”
17
Q
Total filtration of fluoroscopy equipment must be at least:
A
2.5mm al/eq
18
Q
cumulitive timing device in fluoro creates an audible sound after:
A
5 minutes
19
Q
lead used in fluoroscopy must be at least:
A
.5mm pb/eq
20
Q
Fluoroscopy xray intensity at tabletop must not exceed:
A
10R/min
21
Q
Fluoroscopy uses a high KV and low MA to
A
minimize dose
22
Q
Fluoroscopy MA must not exceed:
A
5MA
23
Q
Air exposure is measured in:
A
Traditional - Roentgen (R) ; SI - Air Kerma - grays in air (gyA)
24
Q
Absorbed dose is measured in:
A
Traditional - RAD; SI - grays in tissue (gyT)
25
1 Gray is equal to:
100 Rads
26
Dose equivelent (tissue damage due to dose) is measured in:
Traditional - REM; SI - Seivert
27
RAD X QF =
REM
28
Activity is measured in:
Traditional - Curie; SI - Bacquerel
29
Roentgen (T) =
Air Kerma (SI)
30
RAD (T) =
Gray (SI)
31
REM (T) =
Sievert (SI)
32
Curie (T) =
Bacquerel (SI)
33
Quality Factor for Xray. Gamma, Beta =
1
34
Quality Factot for Alpha:
20
35
An Optically Stimulated Luminescence (OSL) Badge:
Uses Aluminum Oxide and is accurate to 1 mREM (like our badge)
36
A film badge uses:
Real film (old school)
37
A Thermoluminescent Dosimeter (TLD) badge uses:
lithium fluoroide - used in nuclear medicine
38
A pocket dosimeter uses:
ionization chamber, has an immediate readout, but not highly accurate
39
EMR - Elecrtromagnetic Energy:
Bundles of pure energy, no mass, no charge, moves at speed of light, waveform movement
40
Photon:
smallest quantity of any type of EMR;
| AKA quanta or ray
41
ionizing radiation:
energy with the ability to disrupt atomic structure thereby creating ions
42
Energy Based:
```
low LET;
XRAY/Gamma;
bundles of pure energy;
no mass/charge;
travel at speed of light;
waveform movement
```
43
Matter Based:
```
high LET;
Alpha, Beta, Photon, Neutron;
have matter/mass/charge;
travel slower than the speed of light;
straight line movement
```
44
Primary radiation:
radiation produced in xray tube, AKA useful beam
45
secondary radiation:
a brand new xray produced in the patient
46
Scatter:
re-directed primary radiation due to interraction with matter
47
remnant radiation:
portion of the primary beam that survives the trip through the patient
48
leakage radiation:
X-ray that escapes the tube housing at a point other than the tube window
49
off focus radiation:
X-ray produced at points of the anode other than the true/actual focal spot
50
Annual dose limit (Occupational) for whole body:
5 rem (50 mSv)
51
Annual dose limit (Occupational) for lens of eye:
15 rem (150 mSv)
52
Annual dose limit (Occupational) for skin/extremities:
50 rem (500 mSv)
53
Annual dose limit (Occupational) for whole body cumulitive:
Age x 1 rem (age x 10 mSv)
54
Annual dose limit (Occupational) for fetus (9 month):
0.5 rem (5 mSv)
55
Annual dose limit (Occupational) for fetus (1 month):
.05 rem (0.5 mSv)
56
Annual dose limit (Occupational) for Student less than 18 years old:
0.1 rem (1 mSv)
57
Annual dose limit (PUBLIC Exposure) for Infrequent Exposure:
0.5 rem (5 mSv)
58
Annual dose limit (PUBLIC Exposure) for Frequent Exposure:
0.1 rem (1 mSv)
59
3 things for xray production:
source of free electrons, acceleration of electrons (kv); Halting of accelerated electrons (Tungsten)
60
Photon:
smallest quantity of any type of electromagnetic energy
61
Amplitude:
one half the range from crest to valley
62
Frequency:
number wavelenths that pass a given point per second
63
frequency is measured in:
Hertz (Hz)
64
Wavelength:
the distance from one crest to the next or valley to valley
65
wavelength is measured in:
Meters
66
Velocity:
All EMR's travel at the speed of light (c)
67
speed of light =
frequency x wavelength (c = f x ?) - symbolized by the figure "lambda"
68
Velocity is
constant
69
Speed of light:
3 x 10^8 m/s
70
xray tube consists of:
a cathode and anode encapsulated within a glass envelope and then encased in a protectuve housing
71
why a glass envelope?
to maintain a vacuum within
72
Why a vacuum?
so electrons accelarated from cathode to anode dont bump into anything AND to prevent the filament from burning
73
Cathode:
the negative side of the xray tube whose function is to emit electrons
74
Cathode consists of
a filament (tungsten), a focusing cup, and associated wiring
75
Thermionic Emission:
electron emission from a heated source
76
Electron cloud/space charge:
collection of electrons "hover" off of the filament when prep/rotor pressed
77
focusing cup:
cup that encases the filament, possesses a negative potential focusing electrons away from the cathode side
78
Anode:
positive side of the xray tube whose function is to receive the stream of high speed electrons
79
Anode consists of
Anode, stator, rotor, associated wiring
80
metallic housing:
protects the xray tube within, absorbs unusable xrays
81
oil-filled tube housing:
protects from unnecessary radiation, electrical risk, conducts heat away
82
Tungsten:
high melting point, high atomic number (74), good conductor of heat/electricity
83
Incident electrons:
electrons boiled off the filament accelerated toward the anode disk, possess massive kinetic energy
84
KE =
1/2m x V^2 (kinetic energy)
85
Voltage -
the force that propels electrons
86
KVP -
the force of electron propulsion from cathode to anode
87
As KVP goes up, the force ofelectron propulsion:
goes up
88
MA:
the number of electrons thermionically emitted from cathode filament per second
89
Amperage:
the number of electrons
90
1 Ampere:
6.3 x 10^18 electrons
91
MAS:
the number of electrons accelerated from cathode to anode
92
MAS has primary control of:
image density
93
Density:
overall image blackness
94
Bremstrahlung Interaction:
BRAKING; strength exactly equal to the amount of electron kinetic enegy lost
95
A vast majority of xrays created are:
Bremstrahlung
96
Characteristic Interaction:
COLLISION; strength equal to the difference in binding energies collision
97
Tungsten Binding Energies: K Shell -
69.5 KEV
98
Tungsten Binding Energies: L Shell -
12.1 KEV
99
Tungsten Binding Energies: M Shell -
2.8 KEV
100
Tungsten Binding Energies: N Shell -
0.6 KEV
101
Tungsten Binding Energies: O Shell -
0.08 KEV
102
Tungsten Binding Energies: P shell -
0 KEV
103
Classical or Coherent -
AKA Thomson or Rayleigh - SPONGE; secondary xray = primary xray
104
Photoelectric Interaction -
inner shell collision, characteristic cascade
105
Linear graph -
dose and response are proportional (straight line)
106
nonlinear graph -
dose and response not proportional (curved line)
107
threshold -
a certain dose is required before a response occurs
108
nonthreshold -
any exposure will cause a response
109
radiation protection is based upon:
nonlinear, nonthreshold
110
somatic effect:
damage sustained by a living organism as a result of exposure to ionizing radiation
111
stochastic effect:
doubt (probabilistic)
112
nonstochastic:
no doubt (deterministic)
113
fractionation:
several low dose exposures delivered over a long period of time
114
protraction:
single high dose exposure over a short period;
115
a single high dose is:
more harmful than several low doses
116
LET -
amount of energy transferred to tissue per unit of distance traveled in tissue
117
High LET:
have matter, mass, charge, straight line movement, slower than the speed of light
118
Low LET:
no charge, no mass, travel at speed of light, waveform movement
119
high LET:
Alpha (dangerous)
120
OER:
Oxygen Enhancement Ratio
121
As OER goes up, biological damage
goes up
122
RBE: Relative Biological Effectiveness -
biological damage produced by radiation in tissue
123
Quality factor for Xray, Gamma, & Beta =
1
124
Quality factor for Alpha =
20
125
Direct Action =
high LET
126
Indirect Action =
low LET
127
Single strand break -
point mutation (low LET)
128
Double strand break =
rupture of both DNA side rails
129
Mutation -
Alteration of DNA base sequence
130
Target theory:
master molecule within a cell; unique or key molecule, cannot be replaced
131
Apoptosis:
programmed cell death, occurs during interphase
132
Law of Bergonie and Tribondeau:
cells most sensitive to radiation injury/death include least mature/specialized, high reproduction activity, longest mitotic phase
133
Radiosensitive cells:
erythroblasts, lymphocytes, epithelial/endothelial tissue, oocytes, sperm, intestinal
134
Radioinsensitive cells:
muscle, nerve, bone, cartilage, tendons, ligaments
135
ARS - acute radiation syndrome:
a collection of symptoms associated with a high level of radiation to the whole body in a short period of time
136
4 Stages of ARS -
Prodromal stage (initial); Latent; Manifest Illness; Recovery/Death
137
Prodromal stage occurs:
within hours, after a whole body dose of 100 Rads ++
138
Latent stage occurs:
after prodromal, no symptoms, appearance of feeling better
139
Manifest stage:
symptoms visible, 3 types - hemaopoeitic, gastrointestinal, cerebrovascular
140
Hematopoeitic:
100+ Rads of whole body dose; AKA bone marrow syndrome; death in 6-8 weeks
141
Gastrointestinal:
600+ Rads of whole body dose; death within 3-10 days as a result of epithelial damage to GI tract
142
Cerebrovascular:
5000+ Rads of whole body dose; death within a couple hours-days due to increased intra cranial pressure due to damaged vessls leaking
143
X-ray was discovered
11/8/1895 by Roentgen
