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Flashcards in Radiology Deck (188):
1

Personnel who restrain animals should never do what?

sit on or lean over the x-ray table

2

T/F Radiographers must allow as much distance as possible between themselves and patients.

true

3

All personnel present in the radiography room when an exposure is made should wear?

appropriate protective lead apparel: gloves, gown, thyroid

4

T/F Genetic damage is not detectable until further generations are produced.

true

5

When radiographing a long bone, which joints must be included?

the joints immediately distal and proximal to the bone

6

T/F The smallest field size possible should be used for any given area of the body.

true

7

T/F Positional terms are named according to where the primary x-ray beam enters and exits the anatomic area of interest.

true

8

T/F As a general rule of thumb, canine patients tend to resist too much restraint and feline patients respond to a calm, authoritative approach to restraint.

false

9

Why should the patient's coat always be checked before taking radiographs?

to ensure that it is dry and as clean as possible

10

What is the purpose of the x-ray tube?

to produce a controlled x-ray beam

11

T/F Low kilovoltage peak (kVp) and high milliamperage second (mAs) techniques should be used as often as possible to prevent damage to the anode.

false-low kVp and low mAs

12

X-ray tube failure is usually a result of what error?

technical error, x-ray tubes should be cared for properly

13

The electrical components of the x-ray machine consist of?

the transformer, the generator, the line-voltage compensator, the timer, and the rectifer

14

Energy travels in ____ the length of which is measurable.

waves

15

How do short wavelengths differ from longer ones?

shorter wavelengths have a higher frequency and penetrate farther than rays having longer wavelengths

16

______ is a form of electromagnentic radiation produced when electrons moving with great speed collide with matter.

x-radiation

17

The ability of x-rays to excite and ionize molecules within cells can cause what?

severe damage or death to those cells

18

The first written report concerning x-rays and their use for medical and surgical diagnosis was made in _____. The author and discovered was ____ _____

1895, Wilhelm Roentgen

19

The kVp controls what? What does the mAs control?

the wavelength and penetrating power of x-radiation, the number of x-rays produced

20

What is the most common artifact in veterinary radiography?

motion

21

T/F Radiation of a longer wavelength has better penetrating ability and therefore produces a higher-quality radiograph.

false

22

A foam wedge should be placed under the sternum to elevate it to the same horizontal level as the spine for what views?

a lateral thoracic and thoracolumbar view

23

To obtain optimal radiographs of the spine, the disk spaces must be nearly _____ to the tabletop and in _____ alignment with each other.

perpendicular, parallel

24

T/F Manually extending a patient's front and rear limbs for a spinal view is not contraindicated if the patient has a spinal column injury.

false

25

T/F A ventrodorsal thoracic view is contraindicated in a patient in respiratory distress.

true

26

When subtle lung metastasis is suspected what is recommended?

both right and left lateral views of the thorax (3 views)

27

The thorax should be radiographed during peak _____, and the abdomen should be radiographed during peak _______

inspiration, expiration

28

When viewing a radiograph of an animal's abdomen in a ventrodorsal or dorsoventral position, the animal's head is _____ of the viewbox and the patient's right is on the ____

top of, viewers left

29

T/F A slight difference in density is low contrast(long scale), a high difference in density is high contrast(short scale)

true

30

What is the most important questions to answer when evaluating the technique of a radiograph?

"is the film overpenetrated or underpenetrated(an indication of kVp)" in otherwords are the outlines of structures visible

31

For soft tissue what contrast is desirable? For bone tissue?

low contrast(many shades of gray), high contrast

32

The state of chemicals and screen-film combinations can affect the quality of what?

of radiographs and mimic inappropriate exposures

33

The darkroom must be clean, organized, and what else?

completely light proof

34

All chemicals must be kept at the same temperature to prevent what?

reticulation

35

T/F Bacterial, fungal, and algal growth are a common problem in hand-processing tanks and can be controlled by cleaning tanks with 1% chlorine bleach when they are drained.

true

36

T/F The legal requirement for keep radiographs is 7 years; however, it is advisable to keep them until the patient dies.

true

37

T/F Approximately 95% of the exposure recorded on a film is due to the light emitted from the intensifying screens. Only 5% of the exposure of the film results from the ionization of x-rays.

true

38

T/F A cassette must contain close contact between the intensifying screens and the film.

true

39

The primary function of the ____ is to reduce the amount of radiation exposure required to produce a diagnostic radiograph

intensifying screen

40

____ screen speeds require a small exposure and produce less detail; ___ screens require a larger exposure and produce greater detail.

faster, slow

41

T/F Screens don't have to be cleaned regularly because dirt and hair do not get on the screen.

false

42

What can cause artifacts on the screen and lead to a wrong diagnoses?

dirt and hair

43

X-ray film is manufactured with ____ and ____

various speeds and latitude

44

The purpose of a ____ is to reduce the amount of scatter radiation and increase the quality of the radiographic image.

grid

45

What is the most effective way to reduce backscatter?

to limit the size of the x-ray beam to include only the image receptor

46

Exposure to the radiographic film to x-rays makes the film ____

black

47

T/F The higher the tissue density, the higher the radiographic density.

false-lower radiographic density

48

What is the most common cause of poor radiographic contrast?

inappropriate exposure factors (kVp, mAs, exposure time)

49

There are 5 radiographic densities with the exception of ____.

air

50

How does air appear on a radiograph? Where is it?

black, commonly seen in lungs and as gas in the intestines

51

How does fat appear on a radiograph? Where?

white, usually found in the abdomen and under the skin

52

How does soft tissue appear on an radiograph? Where?

white, consists of internal organs like the liver, kidney, and intestines

53

How does bone appear on a radiograph?

whiter

54

How does metal appear on a radiograph?

vivid white, an example is lead

55

One of the densities called ____ can be difficult to visualize if not surrounded by fat.

soft tissue

56

What tissues are most sensitive to radiation induced damage?

all living cells, rapidly dividing cells (bone marrow), reproductive organs (no pregnant women)

57

How old do you have to be to be involved in radiographic procedures?

18 or over

58

Other tissues that are readily sensitive to radiation are?

bone, lymphatic, dermis, leukopoietic, hemopoietic, and epithelial tissues

59

What are 3 primary method by which personnel are exposed to radiation during radiography?

primary beam, secondary (scatter) radiation caused by interaction of the primary beam with objects in its path, and leakage radiation from x-ray tube housing

60

Damage to the body induced by radiation that becomes manifest within the lifetime of the recipient is?

somatic damage

61

What are 10 things you can do to decrease your radiation exposure?

1. never hold the x-ray tube
2. wear film or TLD badges near the collar
3. maintain darkroom chemicals in good operating condition
4. have the x-ray machine calibrated annually
5. don't aim the x-ray beam directly at any personnel
6. use a 2.5mm aluminum filter to remove soft x-rays
7. use collimation whenever possible to decrease field size and scatter radiation
8. never let any part of the body within the primary beam
9. use mechanical restraints whenever possible (sandbags)
10. use chemical restraint whenever possible (anesthetize)

62

What is the name of the radiation monitoring device you wear?

film badge a type of dosimeter

63

What is the MPD? and who is responsible for setting dose limits?

maximum permissible dose is the maximum dose of radiation that a person may receive in a given period, NCRP national committee on radiation protection and measurements

64

The unit of absorbed dose is?

Gy gray

65

1 Gy =

100 rad

66

The quantity of energy imparted by ionizing radiations to matter per unit of mass of the matter

absorbed dose

67

The quantity obtained by multiplying the absorbed dose in tissue by the quality factor.

dose equivalent

68

The unit of dose equivalent is?

Sv sievert

69

1 Sv=

100 rem

70

What lead equivalent do gloves and gowns need to be in order to be safe?

at least 0.5mm thickness

71

How do you maintain protective gear?

aprons are hung vertically over a sound surface(not 3< cm in diameter) or laid flat when not in use, gloves are placed on vertical holders that allow air to circulate throughtout the inside, lead aprons and gloves should be inspected periodically for damage

72

Secondary radiation caused by interaction of the primary beam with objects in its path.

scatter radiation

73

The amount of scatter radiation is determined by what 4 factors?

intensity of the beam, the composition of the structure being radiographed, the kVp level, and the thickness of the patient

74

What is primary radiation?

the path that the x-rays follow as they leave the tube

75

Several important factors must be considered if an accurate reproduction is to be made:

welfare of the patient, restraint and immobilization of the patient, minimal truama to the area of interest, and the least risk of exposing those assisting with the examination to radiation

76

What instrument is used to measure the anatomic area of interest? Measurements are in what increments?

a caliper measures part thickness in centimeters

77

What are the required views?

two views of each anatomic area taken at right angles to each other minimum

78

T/F X-rays produce a radiograph

true

79

The amount of electrical energy being applied to the anode

mA milliamperage

80

The amount of electrical energy being applied to anode and cathode to accelerate the electrons from the cathode to the anode

kV kilovoltage

81

A number of x-rays traveling together through space at a rapid speed

x-ray beam

82

A visible photograph record on film produced by x-rays passing though an object

radiograph

83

A restricting device used to control the size of the primary beam

collimator

84

A decrease of x-ray intensity on the anode side of the x-ray beam caused by the anode target angle

heel effect

85

Difference in density and mass of two adjacent anatomic structures

contrast

86

The distance between the source of x-rays and the image receptor or film

source image distance (SID) formerly called FFD

87

How does energy travel?

fast moving electrons is produced at the cathode(filament) and directed to the anode->as electrons collide and interact with the atoms of the target on the anode energy is produced

88

T/F 99% is the form of roentgen radiation and 1% is a great amount of heat.

false

89

_____ is the result of the interaction of the electrons and the atoms in the target.

heat

90

What are the two electrodes found in an x-ray tube? What role do they play in the movement of the electrons?

anode and cathode, the negative charge at the cathode are attracted to the positive anode and collide producing x-rays and heat

91

What are the two types of anodes?

stationary and rotating anode

92

the _____ cannot withstand large amounts of heat, and the angle can range from 15 to 23 degrees altering the "focal spot" size.

stationary anode

93

_____ has a spindle that contains molybdenum which dissipates heat, but the smallness of the angle is limited to 20 degrees vertical

rotating anode

94

What is the purpose of the cathode? What metal is used to form the filament?

to provide a source of electrons and direct them toward the anode, a coiled wire filament that emits electrons when heated

95

How are x-rays produced?

1. a source of electrons
2. a method of accelerating the electrons
3. an obstacle-free path for the passage of the electrons
4. a target in which the electrons can interact releasing energy in the form of x-rays
5. a envelope(tube) to provide a vacuum environment to prevent rapid oxidation of the elements

96

How does the collimator help reduce unnecessary radiation exposure?

by controlling the size of the primary x-ray beam

97

What features are found on the control panel of an x-ray machine?

on/off switch, voltage compensator, kilovoltage selector, milliamperage selector, timer, exposure button, warning light

98

The mA is only up to how fast?

300 mA

99

20mA X 1/2 sec =

10 mA

100

300 mA X 1/60 sec =

5 mA

101

_____ controls degree of darkness, ____ controls contrast shades of gray

mA, kVp

102

Quality of x-rays change ____, quantity of x-rays ____

kVp, mA

103

Describe how to collimate for lateral thoracic

right side down, inspiration, manubrium to last rib, sternum elevated, 7th cervical vertebral body to the first lumbar vertebral body

104

Describe how to collimate for ventrodorsal thoracic.

all thoracic vertebrae from c-7 to l-1, crainial legs extended, beam center over caudal border of scapula t-6, at highest point sternum

105

T/F Always have a marker on an x-ray in the field of view.

false

106

The degree of blackness or “darkness” on a radiograph

radiographic density

107

A device made of lead strips embedded in a spacing material, placed between the patient and the film, designed to absorb non-image-forming radiation.

grid

108

This distortion occurs when the x-ray beam is not directed perpendicular to the film surface

elongation

109

Distortion of anatomic structure because the anatomic area is far from the image receptor

magnification

110

Distortion of anatomic structures when the image appears shorter than actual size due to the plane of interest not being parallel to the film surface

foreshortening

111

A lightproof encasement designed to hold x-ray film and intensifying screens in close contact

cassette

112

Sheets of luminescent phosphor crystals bound together and mounted on a cardboard or plastic base

intensifying screen

113

The total number of x-rays that reach the film, the penetrating power of the x-rays, the developing time, or the temperature of the developer effect what?

radiographic density

114

Subject contrast, kVp level, scatter radiation, film type, and film fog effect what?

radiographic contrast

115

How does scatter radiation effect radiograph?

Since inappropriate areas of the film are being exposed, contrast is decreased and radiation arising from sources behind the image plane may be scattered back to the image or backscatter

116

A _____is a device placed between the patient and the radiographic film that is designed to absorb non-image-forming x-rays (scatter radiation).

grid

117

What are factors that affect radiographic detail?

image sharpness, clarity, distinctness, and perceptibility

118

What are the 3 properties that determine the efficiency of a screen?

1. They must have a high level of x-ray absorption
2. They must have high x-ray-to-light conversion with suitable energy and color
3. There must be little or no “afterglow” once radiation has ceased

119

How is an intensifying screen constructed?

it has four integral layers: a base or support, a reflective layer, a phosphor crystal layer, and a protective coat

120

T/F Damage to the intensifying screen surface is permanent and cannot be repaired.

true

121

Name three things that x-ray film are sensitive to

light, humidity, moisture

122

What metal can be retrieved the developing solutions?

metallic black silver

123

Always store cassettes how?

vertically upright, lid on, lights off

124

if film is black what does it mean? Clear? Trees?

exposed, never exposed, static electricity

125

Collimation for abdomen ventrodorsal view

right side down, diaphragm to femoral head, expiration, beam center/meaurement should be caudal aspect of 13th rib

126

Collimation for abdomen later view

right side down, pull hind limbs caudally, foam pad placed between femurs, foam pad placed under the sternum, diaphragm to caudal femoral head, expiration, beam center/measurement caudal aspect of 13th rib

127

When taking a lateral thoracic where should the x be over? Where is the diaphragm located?

heart (caudal border of scapula), 6 ribs up or 7 ribs down

128

Heat resistant metal used in the filament of the cathode

tungsten

129

This term refers to how easily details can be perceived on a radiograph

radiographic quality

130

Primary factor affecting density is ____

mAs

131

Example of ________ damage include cancer, cataracts, aplastic anemia, sterility

somatic

132

Outer shadow of an object being radiographed

pneumbera

133

As the number of electrons increased this increases

mA

134

The higher the ______, the faster the electrons accelerate increasing the energy of the x-rays produced when the electron cloud collides with the anode (target)

kV

135

Some pathologic conditions including ascites, pleural effusion, and cardiomegaly require an increase in ___ up to 50% to increase radiographic density.

mAs

136

T/F When radiographing the pelvis in a lateral position, a foam wedge should be placed between the patient's stifles to keep the femurs parallel.

true

137

Measurement for the lateral pelvic view should be taken over the ____, and measurement for the ventrodorsal view should be taken at the ____.

trochanter, acetabulum

138

T/F To use the PennHIP method of diagnosing canine hip dysplasia, the veterinarian and technician must receive special certification.

true

139

T/F Sedating the patient is not often used to take radiographs to diagnose hip dysplasia.

false-is often

140

What should be on the film label?

1) name and address of the hospital practice or veterinarian
2) date the radiograph was taken
3) patient identification-name of owner, patient, age, sex, and breed

141

Why is it important to label film correctly?

so it can identified at a later date, and for legal reasons

142

T/F The only legal labeling of a radiograph is what is in the film emulsion.

true

143

What are the views and extremities?

ventrodorsal, lateral, craniocaudal, palmer, planter

144

State the four factors that must be considered for accurate reproduction of an anatomic area:

1) welfare of the patient
2) restraint and immobilization of the patient
3) minimal trauma to the area of interest
4) the least risk exposing those assisting with the examination to radiation

145

If a radiographer is unsure where to measure a particular part, the measurement should be made where?

over the thickest area

146

When there is a large difference in thickness in a particular area, it is advisable to make two separate radiographs with different?

exposures

147

T/F If only a small difference in tissue density exists, a compromise should be made.

true

148

Exposing a large area that is not necessary increases the amount of scatter radiation which decreases _________

radiographic contrast

149

When a marker is placed on a cassette for craniocaudal or caudocranial views, it should be placed on the _____ aspect of the extremity.

lateral

150

T/F In dorsoventral or ventrodorsal views, the marker should be placed on the cassette to identify one side or the other.

true

151

When a lateral projection of the abdomen or thorax is taken, the marker should indicate?

the side that is down on the table or cassette

152

When a lateral projection of an extremity is taken, the marker should be placed?

cranially to (in front of) the leg

153

T/F A radiograph is a two-dimensional picture of a three-dimensional structure.

true

154

T/F Two views of each anatomic area are taken at right angles to each other.

true

155

The importance of two views is exemplified when radiographing a ____.

fractured bone

156

How should a lateral thorax radiograph be placed on the view box for viewing?

all laterally positioned anatomy should face the viewer's left, with the spine at the top

157

What should the film look like for OFA(Orthopedic Foundation for Animals)?

extended view of the pelvis: wing of the ilium to stifle joint of long bone and the joint below it too (all three bones must be seen)

158

What is the purpose of the OFA?

lowering genetic diseases for breeders

159

How old must a patient be for OFA? PennHip?

24 months old, no age requirement

160

Which is better OFA or PennHip why?

PennHip because it gives a better evaluation by checking joint laxity with 3 different views

161

What is hip dysplasia?

abnormal formation of the hip socket

162

What does it mean for film to be "blue-sensitive?"

highly responsive to ultraviolet, violet, and blue spectrum of light

163

What is nonscreen film sensitive to?

ionizing radiation and pressure

164

List and describe the 6 developer components?

1) developing agents(chemical compounds that convert grains of silver into black metallic silver)
2) accelerators(chemicals that increase the activity of the developer)
3) preservatives(prevent rapid oxidation/prevent staining of emulsion layer)
4) restrainers(limit the action of the developing agent to the exposed silver crystals)
5) hardeners(harden film and prevent excessive swelling of the emulsion)
6) the solvent(has water to dissolve the chemicals)

165

What does the rinse bath do?

stops the developing process, rinses the developer from the film, prevents carryover contamination to the fixer

166

What are the purposes of the fix bath?

to clear the unexposed silver halide crystals from the film and it hardens the gelatin coating so it can be dried without damaging the film

167

What metal is retrieved from the developing soultions?

black metallic silver

168

What are the three solutions? What are they affected by?

developer, water, fixer based on temperature

169

A warmer temperature makes the developer?

faster

170

How is a film developed?

develop->water->fixer(x2)->water(rinse bath 20 mins)->must dry it

171

T/F The duration of the fixation process is usually twice the clearing time and until after the film has lost its "milky" appearance.

true

172

Putting the film back into the fix tank after evaluation for a total of ___ is important to allow maximum hardening of the film.

10 minutes

173

How do you know if you've taken a good view of the pelvis? Field of view?

if the obterator foreman are the same size, tubercoles same size, femurs are straight and parallel, patellas are on top, FOV-pelvis, femurs, stifle joints

174

What are the two basic questions you ask yourself?

1) is the film too light or too dark
2) is there proper penetration

175

If you skip the rinse bath and go to the next chemical what color does the film turn?

green

176

For a dorsalventral view where should the heart be?

closet to the plate

177

Where should the area you're most interested in be?

as close to the image receptor as possibel

178

If bone is too dark than what needs to be decreased?

mAs

179

If bone is too white increase?

mA

180

What does a bent film look like?

crescent/black circle

181

What do you look for on a radiograph?

collimation, artifacts, marker there and on correct side, label, straightness

182

What does a development issue look like on film?

streaks

183

How do you collimate for a lateral pelvis view?

the side of interest closest to the cassette, foam wedge placed between the stile joints to keep the femurs parallel with the cassette, the limb closest to the cassette should be pulsed slightly cranial and the top leg slightly caudal, it includes the entire pelvis and a portion of the lumbar spine and the femurs

184

The _______ view of the pelvis is standard for the evaluation of hip joints for hip dysplasia.

extended

185

What does the mAs control?

darkness (30-50%)

186

What does the kVp control?

penetration (10-15%)

187

What does the mAs control?

darkness (30-50%)

188

What does the kVp control?

penetration (10-15%)