Final Exam Questions Flashcards
1
Q
what is said to be directly proportional to receptor exposure?
mAS, OID, SID, or grid ratio
A
mAS
2
Q
what is the formula for mAS?
A
mA*time = mAS
3
Q
how do you define grid ratio?
A
the ratio of the height of the lead strips to the distance between the lead strips in a radiographic grid
4
Q
the construction of the grid provides for greater absorption of —- radiation than of —-
A
scatter, primary
5
Q
grids are recommended for body parts measuring greater than — cm
A
12
6
Q
The large number of exposures a DR detector can capture and display is its
A
dynamic range
7
Q
If all other things are constant, increasing mAS is required when the part gets thicker in order to maintain
A
receptor exposure
8
Q
what is the purpose of a beam restrictor?
A
minimizing scatter radiation, limit beam to precise anatomical area, and enhance contrast
9
Q
a lead shield placed over male gonads can reduce dosage by as much as:
A
90%
10
Q
more rows and columns will result in — pixels
A
smaller
11
Q
the radiographic quality that is defined as misrepresentation of size/shape is?
A
distortion
12
Q
what type of contrast is better for extremities and shows more detail?
A
high contrast
13
Q
Which element is associated with indirect capture DR?
A
cesium iodide
14
Q
Selecting from available shades of gray and assigning a numerical value to each pixel is known as;
A
quantization
15
Q
what element is associated with direct capture DR?
A
a-selenium
16
Q
what is not essential to the production of x-rays?
A
a rotating anode
17
Q
the target of a diagnostic x-ray tube is usually made of what element?
A
tungsten
18
Q
of total available energy, only about — % is converted to x-ray energy
A
less than 1%
19
Q
the vast majority of available energy is transformed into:
A
heat
20
Q
half-value layer
A
A materials half-value layer, or half thickness. Thickness of material at which the intensity of radiation entering it is reduced by one half
21
Q
The interaction that usually occurs in the K or inner electron shell is:
A
photoelectron effect with true absorption
22
Q
the acute dose of radiation that will result in the death of 50% of a group within 30 days (LD 50/30) is considered to be about – sv.
A
3
23
Q
what is the typical exposure from a PA chest radiograph?
A
0.1-0.2mGy (10-20 mR)
24
Q
the information for hereditary is contained in the:
A
nucleus
25
what stage of cell division is said to be the most sensitive time in cell life?
metaphase
26
an example of sensitive tissue is?
blood forming tissue, fast reproducing cells
27
the greatest contributor of exposure to radiation from manmade sources is:
medical x-rays
28
lead aprons are intended to protect the wearer from:
scattered radiation
29
an OSL radiation monitor can record exposures as low as --- mSv
0.01
30
the annual occupation dose limit is currently:
50 mSv
31
the plane that divides the body into equal right and left portions is?
median sagittal plane aka anteroposterior plane
32
coronal plane
aka frontal plane, divides body into front and back portions
33
transverse plane
horizontal plane that divides body into top and bottom portions, aka axial plane
34
when an object is moving, it can be said to possess what type of energy?
kinetic
35
The position of an element on the periodic table is determined by:
number of protons
36
isotope
atoms having the same number of protons but different numbers of neutrons
37
high energy radiations will possess:
high frequency - short wavelength
38
anode heel effect
variation in x-ray intensity between the anode and cathode ends of the x-ray tube
39
a device used to provide radiographs of similar density, regardless of the part thickness:
phototimer (AEC)
40
A device in the x-ray circuit used to increase supplied voltage to kilovoltage is
step-up transformer
41
A device in the x-ray circuit used to change supplied AC to pulsating DC through the x-ray tube is:
rectifier bridge
42
The range of exposure factors that can produce an acceptable image at a reasonable dose is known as
exposure latitude
43
As each digital image is recorded, the exposure is recognized and a ______ is created and then adjusted.
histogram
44
what is the preferred unit of measure for effective dose?
sievert
45
Gy-a
gray of alpha radiation
46
Gy-t
gray of tissue
47
what is used to make primary beam more homogenous?
filter
48
the most effective method of sterilization is?
moist heat
49
The production of x-rays occurs with the rapid deceleration of fast moving _________ in an x-ray tube.
electrons
50
Blood pressure may be expressed as 120/95. What phase of cardiac action occurs during the “95”?
the phase of relaxation of the cardiac muscle tissue
51
Of the four stages of infection, which is the stage during which the infection is MOST communicable?
disease phase
52
Bone projections vs. Depressions
Projection - grows out of bone surface, depressions - indentation or hollows in the surface
53
Condyle
Rounded process that forms part of a joint
54
Coracoid
A pointed projection
55
Coronoid
Beaklike projection
56
Crest
A bony ridge
57
Epicondyle
A projection above a condyle
58
Facet
A small, smooth process that forms part of a joint
59
Head
Rounded, wide end of a long bone
60
Malleolus
A club shaped projection
61
Process
A general term for projection
62
Protuberance
General term
63
Spine
A sharp process/ridge
64
Styloid
A long, sharp process
65
Trochanter
One of the large rounded processes of femur
66
Tubercle
A small rounded process
67
Tuberosity
A rounded process larger than a tubercle, often used interchangeably
68
Fissure
A linear depression, a groove
69
Foramen
Foramina, a hole in bone for the passage of blood vessels and nerves
70
Fossa
A pit or hollow
71
Groove
A shallow linear depression
72
Sinus
A cavity or hollow space
73
Sulcus
A trenching depression, deep
74
Synarthrosis
Joint that does not move
75
Ampiarthrosis
Joint with very limited motion
76
Diathrosis
A joint that can move freely
77
Prone
Lying face down
78
Recumbent
Lying down, further described with the plane of body
79
Supine
Lying on back
80
Upright
Erect
81
Decubitus
Recumbent with CR horizontal or parallel to the floor
82
mA formula if you know mAS and seconds
mA= mAS/seconds
83
How much is exposure increased when distance is halved?
4 times
84
What are the 3 types of filters?
Inherent, added, and compensating
85
what does a grid do?
absorbs scatter radiation after its produced and before it reaches the receptor
86
what are IP plates made out of?
barium fluorohalide
87
what are CR plates made out of?
photostimulable phosphor
88
what is indirect conversion x-ray?
2 step process in which x-ray is converted to light and then into electrical signal
89
what is a scintillator?
a device that glows when hit by high energy x-ray protons
90
what is a scintillator made out of?
cesium iodide
91
what do complementary metal oxide semiconductors do?
convert light into electrons
92
what is direct conversion x-ray?
one step process that converts x-rays directly into electric signal through amorphous selenium
93
how does quantum mottle happen?
occurs when not enough photons in the detector to provide high quality image, kVp set too low
94
what does PACS stand for?
picture archiving communication system
95
bit depth
number of bits per pixel
96
modular transfer function
(MTF) measurement of resolution
97
what is the pixel size on a 14x14in receptor?
12mm? 17mm
98
pixel pitch
distance from the center of one pixel to the center of the next
99
what is typical bit depth for digital images?
8, 10, or 12 bits
100
what shell in an atom is the most important in x-ray?
k-shell
101
what is the sine wave formula for velocity?
wavelength x frequency = velocity
102
why is tungsten used for a filament material?
high melting point and high mass (74 eletrons)
103
bremsstrahlung radiation
"braking radiation" 100% under 70 kVp, and 85% above 70
104
characteristic radiation
no photons below 70 kVp, 15% above 70 kVp
105
the wavelength and energy of the x-ray beam is said to be ------
heterogenous
106
where is filament located in cathode?
hollow area in cathode called focusing cup
107
what target angle is needed for a 14x17 IR?
12 degrees
108
To demonstrate a left lower anterior rib injury, should the exposure be taken after inhalation or exhalation?
the exposure should be made after the patient exhales completely
109
The ridge that marks the bifurcation of the trachea into right and left primary bronchi is the:
carina
110
Aspirated foreign bodies in older children and adults are MOST likely to lodge in the:
right main bronchus
111
how any pairs of false ribs are there?
4
112
A structure of the neck which functions both in the respiratory and digestive tracts is the:
pharynx
113
The air sacs of the lungs are called the:
alveoli
114
what position will best demonstrate the left axillary portion of the ribs?
LPO
115
The external (lateral) oblique of the elbow best demonstrated the:
Radial head
116
The clavicle is a long bone that articulates with the ________ of the scapula, and medially with the ______________ .
acromion process, sternum
117
The patient has pain and tenderness in the area of the base of the fifth metatarsal. Which view will best demonstrate the area?
30 degree medial oblique
118
the knee joint is located:
½ inch inferior to the apex of the patella
119
In which of the following positions/projections will the talocalcaneal joint be visualized?
plantodorsal projection of the os calcis
120
Which of the following projections of the ankle would best demonstrate the distal tibiofibular joint?
medial oblique 45°
121
What articulates with the bases of the metatarsals?
the cuneiforms
122
The ulna articulates with what portion of the humerus to help form the elbow joint?
trochlea
123
In a PA projection of the hand, the central ray should be directed vertically to the:
3rd MPJ
124
With which of the following does the trapezium articulate?
first metacarpal
125
In order to decrease the OID for a PA projection of the wrist:
the fingers should be flexed
126
That portion of a long bone where cartilage has been replaced by bone is known as the:
metaphysis
127
The most medial of the following structures of the humerus is the:
trochlea
128
The spine of the scapula runs obliquely across the posterior surface of the scapula and ends in a flattened, triangular projection called the:
acromion
129
A depression on the anterior surface of the distal humerus just above the trochlea is the:
coronoid fossa
130
The superior border to the patella is called the:
base
131
The round prominence on the anterior surface of the proximal tibia is the:
tibial tuberosity
132
what are short-term effects of a high dose of radiation?
erythema, radiation sickness, compromised immune system
133
what are short-term effects of a lower dose of radiation?
affects the blood and blood-forming system of bone marrow
134
what are the most common radiation effects called?
long-term, short-term, somatic, and genetic
135
when are short-term effects observed after exposure?
3 months
136
what is the absorbed dose greater than for short-term effects?
500mGy-t
137
when are long-term effects observed after exposure?
several years after exposure, sometimes up to 30 years
138
what are somatic effects?
affect the body and the tissues, both short-term and long-term effects
139
what are genetic effects?
damage to the reproductive cells if the irradiated person. defects are observed in children or grandchildren
140
what is the lethal dose of radiation?
5000 mGy-t, LD 50% within 30 days LD 50/30
141
which effects are predictable? long-term or short-term
short-term
142
threshold dose
a dose level below which there is no effect of radiation on the biological response
143
non-threshold dose
a term used to describe the linear-no-threshold (LNT) model, which assumes that any amount of radiation exposure can cause health effect
144
Why is it important to position the patient so that the heart demonstrates minimal magnification
magnification of the heart could be mistaken for pathologic coronary condition
145
What is the rationale for using 72 in SID when performing chest radiographs
72 in SID compensates for increased OID between the heart and the image receptor
146
place where central ray is lined up for a PA chest XR
midsagittal plane at level of T7
147
To ensure that the scapulae do not superimpose the lung fields when performing a PA chest radiograph, patients should be positioned with their
hands on their hips, with shoulders rolled forward
148
Which of the following structures can best be used to evaluate the degree of rotation on a PA chest
appearance of the SC joints
149
If the clavicles superimpose the apices of the lungs and the first rib on a PA chest radiograph, it can be stated
patients back was arched with the shoulders too far from the image receptor
150
what is the correct central ray entrance point for a lateral chest
midcoronal plane at level of T7
151
What is the correct kVp range for an adult chest radiograph
100-120kVp
152
Which of the following structures can be used to evaluate rotation on a lateral chest radiograph
superimposition of the posterior ribs
153
Which 2 structures are best demonstrated on a PA chest
tracheal bifurcation, manubrial extremity of clavicles
154
Which is a true statement regarding the retrocardiac space
it is best evaluated on a lateral chest radiograph
155
What is the primary indicator of full inspiration
minimum of 10 posterior ribs visible above the diaphragm
156
On a PA chest radiograph which of the following is an accurate statement in reference to the lungs vascular markings
vascular markings should be the same from superior to inferior lung
157
Which of the following conditions would demonstrate absence of the diaphragm contour and blunting of the costophrenic angle
pleural effusion
158
Pneumonitis is another term for which of the following pathologic conditions
pneumonia
159
Which of the following abnormalities would typically be found on a chest radiograph of a patient suffering from congestive heart failure
enlarged cardiac size, pulmonary edema
160
Which of the following are visualized on an AP lordotic chest
ribs are distorted with the anterior and posterior portions superimposed
161
central ray for an AP lordotic chest should be directed
3-4 in below the jugular notch
162
Correct patient positioning for the AP lordotic chest will have the patients coronal plane
leaning posterior 15-20 degrees from the vertical
163
a radiographer who discloses confidential information to unauthorized individuals may be found liable for
A. assault
B. battery
C. intimidation
D. defamation
defamation
164
A radiographer who performs an x-ray examination on a patient without the patient's consent, or after the patient has refused the examination, may be liable for
A. assault
B. battery
C. slander
D. libel
battery
165
The belief that one's own cultural ways are superior to any other is termed
ethnocentrism
166
Blood pressure is measured in units of
millimeters of mercury (mm Hg)
167
Lyme disease is a condition caused by bacteria carried by deer ticks. The tick bite may cause fever, fatigue, and other associated symptoms. This is an example of transmission of an infection by
a vector
168
The plane that passes vertically through the body dividing it into anterior and posterior halves is termed the
midcoronal plane
169
What is the relationship between the midsagittal and midcoronal planes?
perpendicular
170
Image identification markers should include
patients name/ID number, date, and a RT or LT marker
171
The best way to control voluntary motion is
a careful explanation
172
what view best demonstrates the cuboid, sinus tarsi, and tuberosity of the fifth metatarsal?
medial oblique foot
173
To demonstrate undistorted air/fluid levels, the CR must always be directed
parallel with the floor
174
Aspirated foreign bodies in older children and adults are most likely to lodge in the
RT main bronchus
175
what condition is characterized by a "flattening" of the diaphragm
emphysema
176
T or F, the lobes of the LT lung are separated by horizontal fissure
F, oblique fissure
177
The contraction and expansion of arterial walls in accordance with forceful contraction and relaxation of the heart is called
pulse
178
The apex of the heart is formed by the
left ventricle
179
The most likely risk of a dose of 15 rad to the fetus during the latter part of the third trimester of pregnancy is
a childhood malignant disease
180
How are wavelength and energy related?
inversely
181
what unit of measure is used to represents absorbed dose?
gray
182
The unit of measurement used to describe effective dose to biologic material is
sievert
183
In an AEC system, which component is responsible for avoiding overexposure of the patient and potential tube overload?
backup timer
184
The use of optimum kV for small, medium, and large body parts is the premise of
fixed kV, variable mAs technique chart
185
Which TWO of these components can collect and convert light into an electrical signal for image production?
1. Charge-coupled device (CCD)
2. Photodiode
3. Scintillation layer
4. Thin-film transistor (TFT) array
1. Charge-coupled device (CCD)
2. Photodiode
186
Radiation with a high rate of linear energy transfer (LET) will result in which two (2) of the following?
1. Concentrated tissue damage
2. Decreased tissue damage
3. Decreased risk of biologic harm
4. Rapid energy disposition
Concentrated tissue damage, rapid energy deposition
187
The philosophy that there is no safe dose of radiation refers to what kind of radiation effects?
1. Acute radiation syndrome
2. Deterministic effects
3. Stochastic effects
4. Linear threshold effects
Stochastic effects
188
What is the role of the image processing software in a digital radiography system?
1. To control the radiation dose administered to the patient
2. To convert raw data from the digital detector into viewable images
3. To adjust the imaging equipment for patient positioning
4. To maintain the operational efficiency of the x-ray generator
To convert raw data from the digital detector into viewable images
189
Chronic obstructive pulmonary disease (COPD) is a global term that encompasses which of the following conditions? (select two)
1. Chronic bronchitis
2. Chronic emphysema
3. Chronic pleural effusion
4. Chronic pneumonia
Chronic bronchitis, chronic emphysema
190
Which of the following is needed to move electrons through a circuit?
1. Amperes
2. Coulombs
3. Ohms
4. Volts
volts
191
What is the primary purpose of using a high-pass filter in digital image processing?
1. To increase sampling frequency
2. To suppress noise and smooth the image
3. To enhance the visibility of sharp edges
4. To decrease the image resolution
to enhance visibility of sharp edges
192
How does tissue density affect attenuation?
1. As tissue density decreases, attenuation decreases
2. As tissue density decreases, attenuation increases
3. As tissue density increases, attenuation decreases
4. Tissue density has no affect on attenuation
As tissue density decreases, attenuation decreases
193
When imaging an elderly patient with osteoporosis for a chest radiograph, which adjustment should be considered to account for decreased bone density?
1. Increase the kVp
2. Decrease the mAs
3. Increase the exposure time
4. Decrease the kVp
decrease kVp
194
A coherent scattering event may also be called:
1. Classical scattering
2. Compton scattering
3. Pair production
4. Photoelectric effect
classical scattering
195
What would be the expected effect on the exposure indicator if a technologist accidentally uses a grid for a pediatric patient where none was indicated without changing technical factors?
1. The exposure indicator would show higher than normal values
2. There would be no significant change in the exposure indicator
3. The exposure indicator would display lower than usual values
4. The indicator would initially decrease, then stabilize over time
The exposure indicator would display lower than usual values
196
Which factor directly influences the signal-to-noise ratio (SNR) in a digital radiographic image?
1. Pixel size
2. Detector material
3. Exposure time
4. Grid ratio
exposure time
197
A radiologic technologist is setting up a mobile radiographic until for a bedside check x-ray. Which component of the unit ensures appropriate beam intensity after selecting the mAs and kVp?
1. Use of a digital grid
2. Bucky assembly
3. X-ray generator
4. Compensating filters
x-ray generator
198
Which factor has the greatest impact on production of characteristic radiation in the x-ray tube?
1. Anode angle
2. Filament current
3. Target material
4. Focusing cup design
target material
199
Which two of these equipment factors affect spatial resolution in radiography? (select two)
1. Bit depth
2. Detector element (DEL) size
3. Fill factor
4. Grid ratio
Detector element (DEL) size, fill factor
200
When it comes to shielding, which material is most commonly used in personal protective equipment (PPE) to protect radiologic technologists from radiation exposure?
1. Al
2. Pb
3. Cu
4. Si
Pb
201
What is the advantage of using a LUT during image processing?
1. Reduces patient dose
2. Increases image acquisition speed
3. Enhances image contrast and brightness
4. Minimizes operator intervention
enhances image contrast and brightness
202
A trauma patient with suspected atelectasis after a motor vehicle accident requires a portable AP chest radiograph. What adaptation is needed to compensate for the patients condition?
1. Perform the exam supine, not semi-erect
2. Increase kVp to compensate for the condition
3. Perform a lateral decubitus instead
4. Increase mAs to compensate for the condition
Increase kVp to compensate for the condition
203
Which organ system response to whole-body radiation exposure has a minimum threshold dose of 2 Gy?
1. Central nervous system syndrome
2. Gastrointestinal syndrome
3. Hematopoietic syndrome
4. Tolerance syndrome
Hematopoietic syndrome
204
What is the recommended maximum dose limit for occupational radiation exposure for radiologic technologists in the United States?
1. 5 mSv per year
2. 10 mSv per year
3. 50 mSv per year
4. 100 mSv per year
50mSv per year
205
In examining the digital radiograph of a hand, a technologist notices that the carpal bones are not as sharply defined. What factor is most likely limiting the spatial resolution in this image?
1. Exposure time
2. Pixel size
3. Grid ratio
4. mA selection
pixel size
206
Increasing the focal spot size has what effect on spatial resolution?
1. Decreased spatial resolution
2. Increased spatial resolution
3. No change in spatial resolution
decreased spatial resolution
207
Dose equivalent is a measure that accounts for:
1. The energy absorbed per unit mass of tissue
2. The type of radiation and its energy absorbed per unit mass of tissue
3. The time rate at which energy is absorbed
4. The biological effectiveness of the absorbed energy
The type of radiation and its energy absorbed per unit mass of tissue
208
An image is taken using 25 mAs with an 8:1 grid. What mAs is needed to maintain image receptor exposure when switching to a 5:1 grid?
1. 9 mAs
2. 13 mAs
3. 56 mAs
4. 74 mAs
13 mAs
209
A radiograph with few shades of gray exhibits:
1. High contrast
2. Long scale contrast
3. Low contrast
4. Medium contrast
High contrast
210
Which of the following devices converts light photons into electrons in a flat panel detector?
1. Amorphous selenium (a-Se)
2. Photodiode
3. Scintillator layer
4. Thin-film transistor (TFT) array
Photodiode
211
When considering the impact on kVp on skin dose, which of the following statements is accurate?
1. Higher kVp settings decrease skin dose due to increased penetration
2. Lower kVp settings decrease skin dose by reducing photon energy
3. Higher kVp settings increase skin dose because of higher energy absorption
4. kVp adjustments have no direct effect on skin dose
Higher kVp setting decrease skin dose due to increased penetration
212
How does the distance between the x-ray tube and the patient affect the need for additional filtration?
1. Decreased distance reduces the need for additional filtration
2. Increased distance requires additional filtration
3. Increased distance reduces the need for additional filtration
4. Distance has no impact on the need for additional filtration
Increased distance reduces the need for additional filtration
213
What term describes a reduction of x-ray beam intensity through scatter and absorption?
1. Attenuation
2. Disintegration
3. Fogging
4. Transmission
attenuation
214
What is the primary outcome of coherent (classical) scattering in diagnostic radiography?
1. The photon is absorbed by the tissue, increasing patient dose
2. The photon is scattered with no energy loss, altering its path
3. The photon directly ejects an electron from the tissue, causing ionization
4. The photon increases in energy as it scatters, creating higher penetration
The photon is scattered with no energy loss, altering its path
215
What role does the choice of image receptor play in minimizing radiation exposure during digital radiography?
1. It determines the level of post-processing required to achieve diagnostic quality images
2. It influences the amount of scatter radiation produced during the examination
3. It varies in sensitivity and efficiency in capturing and converting x-rays
4. It dictates the speed of image acquisition, thereby affecting patient comfort
It varies in sensitivity and efficiency in capturing and converting x-rays
216
When imaging a patient with suspected bronchitis, how should the radiologic technologist adjust the exposure settings from the technique chart, if at all?
1. Increase the kVp to improve image penetration
2. Decrease the mAs to reduce radiation exposure
3. Maintain the same settings for a standard chest radiograph
4. Decrease the kVp to enhance lung detail
Maintain the same settings as for a standard chest radiograph
217
what is deterministic radiation effect?
short-term, threshold, results from high dose over a short time period. examples are skin reddening and radiation-induced cataract formation
218
A radiologic technologist is performing an abdominal radiograph on a pediatric patient. Which of the following techniques would minimize patient exposure while maintaining diagnostic image quality?
1. Using a lower mA and a longer exposure time
2. Using a higher mA and a shorter exposure ti8me
3. Increasing the kVp and reducing the mAs
4. Using a grid to reduce scatter radiation
increasing kVp and reducing the mAs
219
Which of the following measures effective dose?
1. Gray (Gy)
2. Sievert (Sv)
3. Coulomb per kilogram (C/kg)
4. Becquerel (Bq)
sievert
220
What is the effect of doubling the distance between the x-ray source and the image receptor on the quality of the digital image if the IR exposure is maintained?
1. Increased contrast resolution
2. Decreased spatial resolution
3. Increased spatial resolution
4. Increased noise
Increased spatial resolution
221
Bremsstrahlung interactions occur only when the incident electron interacts with:
1. An inner-shell electron
2. An outer-shell electron
3. The electric field of the atomic nucleus
4. The entire atom
the electric field of the atomic nucleus
222
If a radiograph was taken using a 40-inch SID and the image was repeated using an 80-inch SID, what change would be needed to maintain image receptor exposure?
1. Double the kVp
2. Double the mAs
3. Increase the kVp by a factor of 4
4. Increase the mAs by a factor of 4
increase the mAs by a factor of 4
223
What radiation effect is associated with a specific dose threshold?
1. Deterministic effect
2. Somatic effect
3. Stochastic effect
4. Genetic effect
deterministic
224
How does the orientation of the anode-cathode axis in the x-ray tube affect image sharpness during extremity imaging?
1. It has no effect on sharpness
2. Orientation parallel to the limb increases sharpness
3. Orientation perpendicular to the limb increases sharpness
4. Orientation impacts only the exposure time
orientation parallel to the limb increases sharpness
225
Which two of the following is an appropriate use of electronic annotation during digital radiographic imaging? (select two)
1. Indicating laterality (R/L)
2. Indicating technologists initials
3. Indicating the time of the exam
4. Indicating sequencing of the projections
Indicating the time of the exam, indicating sequencing of the projections
226
The SI unit to measure the equivalent dose is:
1. air kerma (Gy-a)
2. roentgen (R)
3. sievert (Sv)
4. gray (Gy-t)
sievert
227
Why is it recommended to increase the mAs when using a grid in radiographic imaging?
1. To compensate for the increased image contrast
2. To adjust for the attenuation of the primary photons
3. To reduce overall radiation dose to the patient
4. To enhance the spatial resolution of the image
To adjust for the attenuation of the primary photons
228
Deterministic effect
Observable adverse biological effects caused by radiation exposure. the severity of change in tissues depends on the radiation dose.
229
In the computed radiography (CR) imaging plate, the response of the phosphor layer when interacting with x-ray photons is to release:
1. A latent image
2. An electrical signal
3. Light photons
4. X-ray photons
light photons
230
Which factor has the greatest impact on the production of characteristic radiation in the x-ray tube?
1. Anode angle
2. Filament current
3. Target material
4. Focusing cup design
target material
231
empyema
pus in the pleural cavity
232
The resistance to electric flow through a circuit is measured in:
1. Amperes
2. Hertz
3. Ohms
4. Volts
ohms
233
Which two of these processes corrects for slight underexposure or overexposure errors caused by incorrect technical factors settings? (select two)
1. Histogram analysis
2. Look-up table (LUT) adjustments
3. Quantization
4. Rescaling
Look-up table (LUT) adjustments, Rescaling
234
Walls that are considered to be secondary barriers should consist of:
1. 0.8 mm (1/32 in) of lead thickness
2. 1.6 mm (1/16 in) of lead thickness
3. 3.2 mm (1/8 in) of lead thickness
4. 4.8 mm (3/16 in) of lead thickness
0.8 mm (1/32 in) of lead thickness
235
What occurs when an incident electron interacts with the force field of an atomic nucleus?
1. Characteristic radiation
2. Photoelectric effect
3. Pair production
4. Bremsstrahlung
Bremsstrahlung
236
Which two of the following should be used to evaluate the spatial resolution of a chest radiograph? (Select two)
1. Heart and associated vasculture
2. Lung markings
3. Visibility of spinous processes of the thoracic vertebrae
4. Trabecula of the bone
Heart and associated vasculture, lung markings
237
When speed is essential in completing an imaging examination, the preferred IR is:
1. CR
2. DDR
3. Film-screen
DDR
238
Which of the following materials is essential to latent image production in computer radiography (CR) imaging systems?
1. Amorphous selenium (a-Se)
2. Carbon fibers
3. Photostimulable phosphor (PSP)
4. Rare-earth metals
Photostimulable phosphor (PSP)
239
Which biological effect of radiation exposure is described by the linear no-threshold model?
1. Deterministic effects
2. Stochastic effects
3. Immediate effects
4. Localized tissue effects
stochastic effects
240
Which is true of a scintillator?
1. Absorbs x-ray energy and emits part as visible light
2. Absorbs x-ray energy and emits that energy as electrons
3. Converts visible light to electrons
4. Converts electrons to visible light
Absorbs x-ray energy and emits part as visible light
241
Photoelectric effect
when light shines on a material causing electrons to be ejected
242
The SI unit for measuring absorbed dose is:
1. air kerma (Gy-a)
2. roentgen (R)
3. sievert (Sv)
4. gray (Gy-t)
gray (Gy-t)
243
What is the purpose of a grid?
1. To remove scatter radiation from the primary beam
2. To decrease radiographic contrast
3. To remove scatter radiation from the remnant beam
4. To decrease dose to the patient
To remove scatter radiation from the remnant beam
244
How many half-value layers (HVL) are required to decrease beam intensity from 100% to 12.5%?
1. 2
2. 3
3. 4
4. 5
3
245
What adaptation to technical factors should be made for a patient with known empyema?
1. Increase mA
2. Decrease exposure time
3. Increase kVp
4. Decrease kVp
increase kVp
246
The ability to produce quality radiographs using a wide range of technical factors is called:
1. Bit depth
2. Dynamic range
3. Exposure latitude
4. Spatial resolution
exposure latitude
247
The ability of an x-ray photon to to penetrate matter is described as the:
1. Attenuation
2. Exposure
3. Quality
4. Quantity
quality
248
What is the linear no-threshold model? (LNT)
direct proportional relationship between radiation exposure and cancer risk
