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Rad Tech Test 2 > Test 2 > Flashcards

Test 2 Flashcards

0
Q

What’s the general purpose of Cassettes?

A
  • has a pair of intensifying screen (1 on front and 1 on back), and are used with dual emulsion film.
  • allows the film exposure to double with a given x-ray
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1
Q

What do cassettes provide?

A
  1. light-tight holder for film during use
  2. rigid support (avoids damage while handling)
  3. suitable mounting for the intensifying screens while in contact with film
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2
Q

Special systems for high detail work (e.g., mammography) use what kind of cassettes?

A

they’re special cassettes only having a single screen and single-emulsion film.

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3
Q

What are Intensifying Screens coated with?

A

*Flourescent crystals

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4
Q

What are Phosphors?

A

Florescent crystals

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5
Q

What happens when Phosphors are exposed to x-rays?

A

Fluoresce (Give off light)

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6
Q

What percentage of the image is formed by the screen light?

A

99%

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7
Q

What’s the purpose of the intensifying screen?

A

Reduce the amount of exposure required (dec. patient dose)

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8
Q

What is the composition of the Intensifying screen?

A 
Support Layer
Reflective Layer
Adhesive Layer
Phosphor Layer
Protective Layer
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9
Q

What is screen speed?

A
  • The efficiency of a screen in converting x-rays to light

* Greater efficiency=less exposure necessary=”faster screen”

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10
Q

What’s industry standard screen speed?

A

100

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11
Q

What screen speed would be 2x’s as fast as a 100-speed screen and require 1/2 as much exposure?

A

200

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12
Q

What’s the screen speed for general purpose radiography?

A

300-400 (good for spinal application)

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13
Q

Screen speed for Extremity radiograph?

A

100

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14
Q

Screen Speed: ultra detail (extremity, non-bucky use)?

A

50

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15
Q

Screen Speed: detail (extremity, non-bucky use)

A

100

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16
Q

Screen Speed: Exceptional detail for routine work?

A

200

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17
Q

Screen Speed: Good detail for routine work?

A

400

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18
Q

Screen speed: Moderate detail for routine work?

A

600

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19
Q

Screen Speed: very high speed, lowdetail?

A

800-1200

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20
Q

Best speeds used for NMS?

A

100 & 600

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21
Q

What happens to the radiographic detail when the speed is greater (fast=50, 100)?

A

More x-rays expose the thick phosphor layer’s large crystals; therefore, LESS radiographic detail

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22
Q

What are the screen phosphors composition?

A

Rare Earth Phosphors (gadolinium, lanthanum, yttrium)

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23
Q

Are Rare Earth Phosphors more efficient?

A

Yes, 4x more efficient than old technology

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24
Q

What is Spectral Emission?

A

*Refers to color of light emitted by a phosphor.

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25
Q

What are typical colors of Spectral Emission?

A
  • green or yellow-green

* blue or blue-violet

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26
Q

Does the light of the screen need to match the spectral sensitivity of the film?

A

Yes

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27
Q

What are the characteristics of the typical Modern Regular/Rapid Screen?

A

Rare Earth Crystals, Moderate Crystal Size, Medium Phosphor Thickness, Reflective Layer, Relative Speed: 200-600

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28
Q

What are the modern screen characteristics of a Detail/Extremity Screen?

A

Rare Earth Crystals, small crystal size, thin phosphor thickness, reflective layer, relative speed: 50-100

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29
Q

What screen has Moderate Crystal Size, Medium Phosphor Thickness, and 200-600 speed?

A

Regular/Rapid Screen

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30
Q

What Screen has Small Crystal Size, Thin Phosphor Thickness, & 50-100 speed?

A

Detail/Extremity

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31
Q

What does this equation represent:

Speed1/Speed2 X mAs1 = mAs2

A

Adjusting Exposure for Variations in Screen Speed

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32
Q

If 10 mAs and 100 speed is good for an ankle radiograph; however, you change the speed to 400. What will the new mAs be?

A 
speed1/speed2 X mAs1 = mAs2
speed1 = 100
speed2 = 400
mAs1 = 10
mAs2 = 2.5
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33
Q

Rules for routine care of screen?

A
  1. handle carefully (no dropping/bumping corners)
  2. never leave cassette lying open
  3. hands ALWAYS are clean & dry
  4. minimize environmental dust
  5. clean screens promptly when dirty (Monthly or more frequent)
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34
Q

Consequence for dirty intensifying screens?

A

Blocks the screen light from reaching the film, creating “screen dirt artifacts”

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35
Q

T or F: Screen builds up static electricity charge which attracts dust and dirt.

A

True

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36
Q

Is it important to have good Film and Screen contact? Why or why not?

A

Yes; if there’s space then light divergence from the screens causes blurring of the film image.

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37
Q

What are some causes of poor film-screen contact?

A
  • pocket of trapped air
  • foreign material in the cassette or screen
  • dents outside or inside cassette
  • damage from improper mounting of screen
  • pad layer deterioration
  • warping of screen from being wet
  • warping of cassette frame due to dropping or rough hangling
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38
Q

What are the following descriptors describing:
*a permanent record of the x-ray image, similar to a photographic film, has emulsion on both sides (duplitized), decreases exposure time/patient dose by 1/2?

A

Radiographic film

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39
Q

How is the film constructed?

A

Has photographic emulsion at each end (dual emulsion) AND polyester base in the center

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40
Q

What are characteristics of the Film Base?

A

Strong/flexible, optically clear, blue tint (reduce eye strain), consistent thickness (for even exposure)

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41
Q

What makes up the photographic emulsion?

A
  • Gelatin (support medium)
  • SILVER HALIDE MICRO-CRYSTALS (active ingredient); silver bromide is 90% & silver iodide is 10%
  • Silver sulfide (catalyst)
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42
Q

How does the emulsion respond to light or x-rays?

A
  • silver halide crystals undergo a physical change
  • when placed in a developer solution the exposed crystals are reduced to black metallic silver and the unexposed crystals are unaffected
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43
Q

What is the pattern of exposed and unexposed crystals on a film?

A

Latent Image

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44
Q

What physical stimuli can expose film?

A

Light, x-ray, heat, certain chemicals or fumes, pressure, age, improper storage (results in “fogging”)

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45
Q

How should a film be stored?

A

clean and dry location, 50-70 degrees Fahrenheit, away from fumes and radiation, standing on edge, expired date clearly visible

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46
Q

What characteristics influence the sensitivity/speed of the film?

A

size of silver halide crystals AND thickness of the emulsion

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47
Q

What does latitude mean with reference to film?

A

wide range of densities can be recorded on the film

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48
Q

What characteristic is inversely related to latitude?

A

Contrast (low contrast film has longer latitude-more grays)

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49
Q

What represents the Y & X-axis of the Sensitometric (H & D) curve?

A

Y-axis is Density of the body

X-axis is a logarithm of relative exposure

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50
Q

What is optical density?

A

Numerical representation of the film’s ability to transmit light.

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51
Q

What is the Toe at the bottom of the H&D curve?

A

the measure of light absorbed by film base, plus any fog

the length of the toe indicates sensitivity of film to fog

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52
Q

What does the Shoulder/D-Max at the top of the H&D curve represent?

A

film’s maximum density (further exposure doesn’t make more density)

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53
Q

The location of the Body of the H&D curve indicates what?

A

Film speed (closer to the left = faster film)

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54
Q

What does slope indicate on the H&D curve?

A

Film contrast (steep = short scale/high contrast)

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55
Q

What is spectral sensitivity?

A

portion of electromagnetic spectrum the film is most sensitive to (green or blue light)

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56
Q

What does the spectral sensitivity of the film match on the screen?

A

Spectral Emission of the screen (inappropriate matching increases exposure required)

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57
Q

What are Film types?

A

Dual emulsion vs. Single emulsion; contrast vs. latitude; spectral sensitivity; speed vs. detail film; duplicating film

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58
Q

A single emulsion film is used for special exposures (ie. mammography) where detail is important; therefore, what is dual emulsion used for?

A

General-purpose radiography (typically quite fast, and moderate to high contrast)

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59
Q

Latitude film provides lots of grays and less__________?

A

Contrast

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60
Q

What type of film is used for examination of body parts (ie. chest) with high subject contrast?

A

Latitude film

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61
Q

Blue films and green films are what type of films?

A

Spectral sensitivity

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62
Q

What is a function of crystal size?

A

Speed vs. detail

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63
Q

What does small and large crystals provide?

A

Small crystals = better detail sharpness

Large crystals = greater speed

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64
Q

Duplicating film uses _________emulsion and has notch on the top edge.

A

Single

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65
Q

When establishing a Processor Quality control program there are 2 necessary equipment?

A

Sensitometer AND Densitometer

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66
Q

What baseline standards should be established when processor is operating optimally?

A
  • chemical change within the past week
  • films have been coming out well
  • sensitometric films have been consitent
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67
Q

What does a sensitometer do?

A
  • Exposes film in darkroom to create a gray scale

* precisely controlled light source

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68
Q

What’s the purpose of a densitometer?

A

*used to measure radiographic densities on sensitometric strip

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69
Q

How are film contrast and latitude related?

A

Inversely (Wide latitude is low contrast-for chest; High contrast is short contrast)

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70
Q

H&D curve: Steep slope with the shoulder at density=4 represents what kind of speed, latitude, and contrast?

A 
Speed = fast
Latitude = short/narrow
Contrast = high
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71
Q

H&D curve: A gradual curve that has a shoulder of 2 represents what kind of speed, latitude, contrast?

A

speed=slow
latitude=long/wide
contrast=low/short

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72
Q

How do you set the Speed Index?

A

Expose a fresh 8x10” film with sensitometer. Measure the radiographic steps with the densitometer, then choose the optical density closest to 1 on the sensitometric stip to equal the speed index.

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73
Q

How do you find the Contrast Index?

A

It’s the difference in the radiographic density between the speed index reading and the optical density reading (using the densitometer) that is 2 steps darker on the sensitometric strip

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74
Q

How do you you identify the Gross Fog Index?

A

It’s the the Base of the H&D curve plus any fog (usually 0.15-0.20). It is the inherent optical density of the film before it has been exposed.

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75
Q

Is a higher Gross Fog Index a faster or slower film?

A

Faster

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76
Q

When processing film Safe Lights inside a dark room need to be?

A
  • at least 4 feet from work area
  • proper bulb size (can’t exceed 15 watts)
  • filter on light that doesn’t allow a spectral emission within the sensitive range of film being used (don’t want to expose film)
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77
Q

Film processing: The film should not be exposed to more than ________ minutes of “safe light”

A

3

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78
Q

If the “safe light” filter has a spectral emission of cherry-red then what is the spectral sensitivity?

A

green- or blue- sensitivity

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79
Q

Manual Film Processing: What’s the optimum time and temperature for immersion of film in developer?

A

5 minutes and 68 degree Farenheit

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80
Q

Manual Film Processing: After rinsing the developer off the film you want to immerse the film in fixer for how long?

A

10 minutes

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81
Q

Manual Film Processing: After fixing the film, washing, and rinsing you’ll dry for how long?

A

20-30 minutes

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82
Q

The Developer qualities are: Activator, Reducing Agent, Preservative, and Restrainer. What are the characteristics of the Activator?

A

The Sodium Carbonate softens the gelatin protective cover on the film

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83
Q

How does the Developer act as a Reducing Agent?

A

The Hydroquinone Reduces EXPOSED silver halide to black metallic silver

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84
Q

What preserve the developer by preventing oxidation?

A

Sodium Sulfite

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85
Q

What chemicals in the Developer act as a Restrainer (prevent over development)?

A

Potassium Bromide and Acetic Acid

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86
Q

Clearing agent is the Fixer is__________ and it dissolves undeveloped____________.

A

Ammonium thiosulfate; silver halides

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87
Q

The Tanning Agent of the Fixer is______ _____.

A

Potassium alum

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88
Q

The Activator of the Fixer is _____ _____, which neutralizes the developer, stopping the development process & maintains the _____.

A

Acetic Acid; acid pH

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89
Q

Automatic developers are a clean, convenient method. The temperature is higher or lower than the manual developer?

A

Higher (92-96 degrees F vs. 68 degree F)

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90
Q

With automatic developer systems there’s constant agitation of chemicals and rapid through-put of film (90-180 seconds). This is good if you take a lot of films. What’s the consequence if you don’t take a lot of films & the processor is running all day?

A
  • Increased rates of chemical replenishment (b/c chemicals degrade faster)
  • If under-replenishment there will be loss of contrast (more gray) and loss of film density
91
Q

What’s the consequence if the chemicals in an Automatic Developer system are over-replenished?

A

loss of contrast (increased fog) and waste of chemical

92
Q

In the dark room, what are causes of lowered contrast (more gray) on a film?

A
  • safe light fog (over 3 min, sensitive to spectral emission)
  • room temp/humidity too high
  • chemical fog from processor (too hot)
  • chemical fog from chemicals (too concentrated)
  • film is expired
93
Q

What are 4 quality control steps that should be done every 1-2 months?

A
  1. complete chemical change and tank cleaning
  2. check replenisher rates
  3. check cycle time (adequate warm-up and temp. check)
  4. sensitometric evaluation
94
Q

What are 3 interaction of X-rays with matter?

A
  1. Coherent Scattering
  2. Compton Effect
  3. Photoelectric Effect
95
Q

What happens with Coherent Scattering?

A
  1. photon enters atom
  2. photon’s energy transferred to atom, causes an excited state
  3. energy given up as a photon of the same energy, but with an altered direction
    (low energy photon changes direction. wavelength is unchanged)
96
Q

What happens with the Compton Effect?

A

Impact with outer orbital electron results in a lower energy photon with a new direction. This is the most common radiation interaction in the body.

97
Q

What happens in the Photoelectric Effect of radiation and matter?

A

Photon collides with inner orbital electron causing outer orbital electron to change shells. Creates Character Radiation.

98
Q

What does Tissue Volume do to affect scatter radiation production?

A

The greater the tissue volume -> the greater the interactions ->increase scatter

99
Q

How does increased kVp affect scatter (Secondary radiation/fog) production?

A

Increased energy increases the # and energy of scattered photons. Also, scatter is more able to escape subject without being reabsorbed (each photon can cause multiple scattered photons of various types with sufficient energy)

100
Q

How does increasing mAs affect scatter production?

A

Increases the # of photons = increases interactions = increases scattered photons

101
Q

What does a grid device (placed b/t patient and film) to scatter radiation?

A

It controls/reduces scatter on film by absorbing scatter

102
Q

What is the Air Gap technique and what’s the purpose?

A

It decreases scatter by increasing the OID

103
Q

When OID increases the magnification (penumbra) increases. How is magnification reduced when OID is increased?

A

Increase the SID

104
Q

Would the field size be increased or decreased to control/reduce scatter?

A

Decrease

105
Q

How does kVP reduce scatter?

A

When decreased

106
Q

What is the Grid ratio?

A

Height(lead strip)/Width(interspacing material) = H/D

107
Q

What grid ratio is best for spinal anatomy?

A

10:1 or 12:1

108
Q

How is effectiveness of a grid determined?

A

By the Grid Ratio (H/D)

109
Q

What are the results of higher grid ratios?

A
  • decrease direction variation permitted
  • require more precise alignment of x-ray beam
  • require more exposure
110
Q

What is the grid Frequency?

A

Number of lead strips per inch

111
Q

What kind of grid aligns the lead strip with the direction of the diverging primary x-ray beam?

A

Focus Grid

112
Q

When the focus grid is aligned at a specific SID what is that called?

A

Grid Radius

113
Q

What is the distance at which the primary beam is parallel to lead strips?

A

Grid Radius

114
Q

What is the range of SID’s which the grid will work acceptably (another way said: the range of distances the grid won’t absorb remnant radiation)?

A

Grid Focal Range (example a grid with a 40” radius may have a focal range of 36-48”)

115
Q

What kind of grid has lamination of 2 grids with lead strips perpendicular to each other?

A

Cross-hatch grid

116
Q

What is a moving grid called?

A

Bucky

117
Q

What does moving the bucky during exposure do to the exposure?

A

Blurs the image of the grid lines so the grid image is not visible on the film

118
Q

What happens with stationary grids?

A

They don’t move during exposure, many very fine lines per inch to avoid objectionable grid lines

119
Q

How many lines per inch do stationary grids have?

A

103 lines/inch

120
Q

What is the undesirable attenuation of the primary x-ray beam (due to misalignment between the grid and x-ray beam)?

A

Grid Cut-Off

121
Q

When do you not have a Grid Cut-Off?

A

When x-ray beam is off-center to one side of the grid (rather than the focal center line)

122
Q

What happens when the grid is tilted, x-ray beam is angled across grid, when SID is outside focal range, grid is reversed?

A

Grid Cut-Off

123
Q

When do you absolutely have to use a grid?

A

When the body part exceeds 12 cm

124
Q

What happens to density when increase mA?

A

Increases

125
Q

When increased time what happens to density?

A

Increase

126
Q

When decrease kVp what happens to density?

A

Decreases

127
Q

When decreasing the grid ratio what happens to density?

A

decreases

128
Q

When increasing film speed (sensitivity) what happens to density?

A

Increases

129
Q

When increase screen speed what happens to density?

A

Increases

130
Q

When patient or part size increase what happens to the density?

A

decreases

131
Q

When developer time &/or temperature increases what happens to density?

A

Increases

132
Q

When developer strength increases what happens to density?

A

Increases

133
Q

When does a developer decrease density?

A

When it’s weak or exceptionally strong (due to over-action of glutaraldehyde preventing full development)

134
Q

Increased SID _________ density.

A

Decreases

135
Q

Increased OID will _________ density.

A

decrease (somewhat due to decreased secondary radiation)

136
Q

A major reduction in field size ________ radiographic density due to decreased secondary radiation.

A

decreases

137
Q

How is contrast primarily controlled?

A

kVp and by controlling secondary radiation fog

138
Q

What reduces contrast?

A

Fog

139
Q

What produces fog?

A

secondary radiation, accidental radiation, processing chemicals, exposure to darkroom chemical fumes, safelight, film age, poor film storage

140
Q

Contrast suffers when patient size increases or decreases?

A

Increases

b/c have to increase mAs creating more scatter/fog AND inc. tissue volume absorbs more radiation creating more scatter

141
Q

Scatter has more energy when kVp is ___________, which increases contrast and reduces fog.

A

Higher

142
Q

Increasing the OID (Air Gap), reducing the amount of scatter and _________ contrast.

A

Increasing

143
Q

Reducing the field size reduces the amount of scatter and __________contrast.

A

Increases

144
Q

Grid prevents scatter from reaching film, thus ________ contrast.

A

Increasing

145
Q

Increasing the grid ratio improves efficiency of scatter control, thus_________contrast.

A

Increasing

146
Q

What happens to kVp and mAs when trying to increase contrast?

A

dec. kVp by 15% and multiply mAs by 2

147
Q

What happens to kVp and mAs when decreasing contrast?

A

Increase kVp by 15% And Divide mAs by 2

148
Q

When measuring radiation exposure and dose what are the conventional units?

A

Roentgen (R), rad, rem, Curie

149
Q

When measuring radiation what are the international (SI) units of exposure and dose?

A

Coulombs/kilogram (C/kg), Gray (Gy), Sievert (Sv), Beckquerel

150
Q

What SI unit matches the Roentgen (R)?

A

Coulombs per kilogram (C/kg)

151
Q

What SI Unit = rad?

A

Gray (Gy)
1 rad = 0.01 Gy
1 Gy = 100 rad

152
Q

What SI unit = rem?

A

Sievert (Sv)
1 rem = 0.01 Sv
1 Sv = 100 rem

153
Q

What SI unit = Curie?

A

Becquerel

154
Q

What is the measurement of the ionization of dry air when and x-ray beam passes through?

A

Roentgen

155
Q

What is rad?

A

Radiation absorbed dose (measures dose to a specific tissue)

156
Q

What is rem?

A

Radiation equivalent in man

157
Q

X-ray photons have a quality factor of ______.

A

one (the higher the number the more efficient at ionizing a tissue)

158
Q

Explain why 1 Roentgen = 1 rad = 1 rem for clinical purposes?

A

Since QF x rad = rem and QF for x-ray is 1. (QF = quality factor & rem = R in man)

159
Q

1 mr (milliroentgen) = ______ ; 1 mrad (millirad) = ______ ; 1 mrem (millirem) = _______

A

0.001 r; 0.001 rad; 0.001 rem

160
Q

Entrance skin exposure (ESE) doses are highest in what kind of radiographs compared to other plain film studies?

A

Spinal radiography

161
Q

What imaging has a much higher ESE than plain film?

A

CT

162
Q

To determine focus to skin distance: measure patient (in inches) and the OID then summate, then subtract from what?

A

SID

163
Q

To calculate patient dose use the focus-skin distance on graph to find exposure (mr/mAs). How would the ESE be calculated?

A

mr/mAs (graph) x mAs (used/known) = mR

164
Q

What’s the percentage of cellular damage (from photon interaction) that is repaired within 3 days?

A

95%

165
Q

What Laws describe Cell sensitivity?

A

The Laws of Bergonie and Tribondeau

166
Q

Cell sensitivity affects the age of cells when young or old?

A

The young cells are more sensitive

167
Q

How is the differentiation of a cell affected by cell sensitivity?

A

High differentiated cell is less sensitive.

Simple cells are more sensitive.

168
Q

How does cell sensitivity affect Mitotic rate?

A

Rapidly dividing cells are more sensitive

169
Q

What type of Metabolic rate is most cellularly sensitive to radiation?

A

Cells that use energy rapidly are more sensitive

170
Q

What are types of radiation effects?

A
  • Somatic (affecting the irradiated individual)
  • Genetic (passed on to future generation)
  • Early (observed w/in months of exposure)
  • Late (latent, manifest after 5-30 years)
  • Stochastic (probabilistic, random)
  • Nonstochastic (deterministic, predictable-due to exposure)
171
Q

What affect of radiation is random and probabilistic (proportional to exposure volume) but the severity is not really affected?

A

Stochastic affect (causing: Cancer, Leukemia, Mutagenesis)

172
Q

Low dose exposure effects are generally _________ .

A

Stochastic

173
Q

Are Stochastic effects somatic or genetic?

A

Can be Either

174
Q

Severity of Nonstochastic affect from radiation is proportional to _______.

A

Dose (generally after large dose)

175
Q

What are 3 short-term nonstochastic effects?

A
  1. GI syndromes
  2. Hematopoietic syndrome
  3. CNS syndrome
176
Q

Late nonstochastic effects are?

A

Cataracts, fibrosis, organ atrophy, loss of parenchymal cells, reduced fertility, sterility

177
Q

Nonstochastic effects are somatic or genetic?

A

Somatic

178
Q

What does Human mortality (LD 50/30) = ~300 rad mean?

A

LD 50/30 = death to 50 percent of an exposed population within 30 days when exposed to catastrophic whole body doses

179
Q

Low dose is now considered to be an exposure to ionizing radiation of _____ rem.

A

0-20

180
Q

At what trimester of pregnancy is there an increased risk of spontaneous abortion with radiation exposure?

A

Trimester 1

181
Q

At what trimester of pregnancy is there an increased risk of birth defects with radiation exposure?

A

Trimester 2

182
Q

What effect model says there is a dose below which no negative effect occurs?

A

Threshold model

183
Q

What effect model suggests there is no safe dose and all exposure is deleterious?

A

Non threshold model

184
Q

We use the threshold model does that mean it’s accurate?

A

No, we use because we opt for better safe than sorry perspectives

185
Q

What hypothesis states that a little bit of radiation can be good for you?

A

Hormesis

186
Q

Is there a human model that backs up Hormesis?

A

No, only an animal model

187
Q

How is Hormesis controlled when applying to humans?

A

Relies on threshold model for radiation exposure. (i.e. ALARA and Risk/Benefit Ratio)

188
Q

What was the annual radiation dose per capita in the early 80’s that was comprised largely by natural causes?

A

360 mrem per capita (~1 mrem per day)

189
Q

In 2006, man made radiation exposure rose to about 1/2 of annual radiation dose per capita, why?

A

Mostly due to diagnostic imaging dose per capita, which rose about 600% or 6 times the amount from the 80’s

190
Q

What does ALARA stand for?

A

As Low As Reasonably Achievable

191
Q

What are 6 important strategies to comply to ALARA?

A
  1. take imaging only with potential patient benefit
  2. use machinery that is working properly and possesses up to date dose-reduction technologies
  3. AVOID retakes
  4. collimate to area of clinical interest
  5. use appropriate shielding
  6. use low dose techniques
192
Q

What are 2 modern technological ways to reduce dose/exposure to patient?

A
  1. use rare earth screens (only 25% exposure vs. calcium tungstate)
  2. use high frequency generators (reduce dose by 30-50%, compared to single phase generators)
193
Q

How do radiation control inspectors look for evidence of collimation?

A

There must be at least 3 margins of collimation on every radiograph

194
Q

How do you ID patients benefit for taking x-ray?

A

ID diagnostic needs by taking history and physical exam, consider pregnancy, consider other diagnostic procedures, obtain previous diagnostic exams, “treat and wait” (wait for x-ray to not affect treatment)

195
Q

How do you avoid retakes?

A

keep equipment and accessories in good working order, processor quality control, MEASURE CAREFULLY, have a reliable technique chart, establish good routines and follow them

196
Q

When collimation to “spine only” on an AP thoracic view how much does it reduce exposure (vs. a full-film exposure)?

A

Reduces by 50%

197
Q

When gonads are in primary beam and shield must be used if:

A

it will not interfere with examination

198
Q

Is contact or shadow shielding more effective?

A

Contact

199
Q

Which view is better for females to reduce breast and ovary dose?

A

PA views (vs. AP)

200
Q

What are other sensitive organs that are important to shield?

A

Eyes & Thyroid

201
Q

When are fastest screens and films with acceptable resolution used?

A

Low dose technique

202
Q

Low dose technique increases or decreases kVp?

A

Increases (up to an acceptable contrast)

203
Q

What is the minimum SID?

A

40” (for low dose)

204
Q

What is the minimum filtration for low dose technique?

A

2.5 mm Al equiv

205
Q

Decreasing Fog levels are important after exposure of film to x-ray. There can be increased fog when the temperature of the___________increases.

A

Developer (maintain proper temperature of developer)

206
Q

Research shows potential for harm when exposure occurs at any stage of pregnancy. When are fetal doses highest?

A

With lumbar and pelvic radiography

207
Q

What is the 10 day rule?

A

Direct pelvic radiation to fertile females should be done only during the first 10 days of the menstrual cycle (day 1=blood flow/menses)

208
Q

What is the exception for the 10 day rule?

A

Emergencies

209
Q

If pregnancy can occur during any part of the menstrual cycle then what does that say for the 10 day rule?

A

It is not valid

210
Q

When is personnel radiation exposure monitoring legally required?

A

When a radiation monitoring expert deems it possible that an individual would receive as much as 25% of the maximum permissible dose.

211
Q

What are some ways to monitor personnel exposure?

A
  • Pocket dosimeters (ionization chambers)
  • film badges (dental film packets in badge)
  • TLDs (thermoluminescent dosimeters utilizing lithium fluoride crystals
  • OSL (optically stimulated luminescence)
212
Q

What monitor is most economical, but least accurate?

A

Film badge

213
Q

What personnel monitor is most precise?

A

Pocket dosimeters

214
Q

What are the most practical and more highly used device by occupationally exposed individuals in medicine?

A

OSL’s (optically stimulated luminescence)

215
Q

What’s a newer name for Maximum permissible dose (MPD)?

A

Effective Dose Equivalent (EDE)

216
Q

What are the EDE limits for an adult non-pregnant worker?

A

5 rem/year (limited to 1.25 rem/calendar quarter)

217
Q

What is the EDE for pregnant workers?

A

0.5 rem/9 months

218
Q

What is the EDE for workers under 18 years old?

A

0.5 rem/year (a little higher than pregnant worker)

219
Q

What is a safety rule for workers in outpatient x-ray facilities that says they should NEVER ______ patients or _____ during exposures.

A

hold; films

220
Q

Who owns the radiographs?

A

The facility/practitioner who took the film

221
Q

What information is HIPAA covered materials?

A

All information (practitioner/facility is responsible to ensure the safety and security of the image )

222
Q

Is it okay to lend films to other practitioners?

A

Yes, but there must be a record of who has the film and they must be returned.

223
Q

What does Radioparent mean?

A

Not having the hapbit of absorbing X-Rays

224
Q

What is the reflective layer of intensifying screen made of?

A

Titaneum Dioxide

Rad Tech Test 2 (1 decks)

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