image production- image acquisition and evaluation quiz

Which of the following is a reason for the loss of spatial resolution in a radiograph? A. Large focal spot B. Increased OID C. Patient motion D. All of the above

all of the above

How many milliseconds are in 0.05 seconds? A. 5 B. 50 C. 500 D. 5000

50 There are 1000 milliseconds in 1 second. To find how many milliseconds are in 0.05 seconds, multiply 1000 times .05 which equals 50.

Which of the following affects shape distortion? A. SID B. OID C. Focal spot size D. X-ray tube angulation

xray tube angulation

Time can be decreased by 1/2 if the kVp is increased by what percentage? A. 10% B. 15% C. 25% D. 50%

15%

Scatter radiation will have the greatest effect on which of the following? A. Spatial resolution B. Receptor exposure C. Contrast resolution D. Distortion

contrast resolution

What is the greatest advantage of digital imaging? A. Contrast resolution B. Spatial resolution C. Decreased exposure D. Less distortion

contrast resolution

Which of the following is an advantage of the air gap technique? A. Easier to position the patient B. Greater exposure latitude C. Allows for a short SID D. Eliminates the need for a grid

eliminates the need for a grid

How will increasing SID affect the spatial resolution on a radiograph? A. Increase spatial resolution B. Decrease spatial resolution C. Eliminate spatial resolution D. Will have no effect on spatial resolution

increase spatial resolution

How are mA and seconds related to each other when used to maintain receptor exposure? A. Directly proportional B. Inversely proportional C. Mutually exclusive D. No relationship exists

inversely proportional

If the mA is set at 400 and the mAs obtained is 80, what is the exposure time? A. 0.1 second B. 0.2 second C. 0.4 second D. 0.8 second

0.2 second

Why is contrast needed in a radiographic image? 1. Makes detail visible 2. Increases sharpness of detail 3. Decreases need for distortion A. 1 only B. 2 only C. 3 only D. 1 & 2 only

1 only

What are the advantages of using high kVp techniques? 1. Less patient exposure 2. Longer tube life 3. All parts are well penetrated A. 1 only B. 1 & 3 only C. 2 & 3 only D. 1, 2 & 3

1,2,and3

Which of the following can be used to reduce unsharpness? 1. Increase SID 2. Decrease focal spot size 3. Decrease OID A. 1 & 2 only B. 1 & 3 only C. 2 & 3 only D. 1, 2 & 3

1,2,and3

If a technique of 300 mA, 1/10 second and 60 kVp is to be changed to 69 kVp, what would be the new time? A. 1/40 second B. 1/20 second C. 1/3 second D. 1/5 second

1/20 second

How many shades of gray can be displayed with a bit depth of 10 bits? A. 512 B. 1024 C. 2048 D. 4096

1024 10 bits is 2 raised to the 10th power or 1024. 2^10

Which of the following would be the most effective at absorbing scatter radiation? A. 5:1 grid B. 6:1 grid C. 8:1 grid D. 12:1 grid

12:1 grid

Geometric unsharpness is directly proportional to which of the following? 1. SID 2. OID 3. SOD A. 1 only B. 2 only C. 1 & 3 only D. 1, 2 & 3

2 only

What advantage is there to magnifying an object? 1. Spatial resolution increases 2. Small objects become visible 3. There is less distortion A. 1 only B. 2 only C. 1 & 2 only D. 1, 2 & 3

2 only

A technique of 400 mA, 0.25 seconds, non-grid could be converted to a technique of 200 mA, with an 8:1 grid and how many seconds? A. 0.50 B. 0.75 C. 1.0 D. 2.0

2.0

What is the magnification factor if an object measures 4 cm but the radiographic image is 8 cm? A. 2X B. 3X C. 4X D. 6X

2X

When an object is placed halfway between the tube and the image receptor the image will be how many times larger? A. 2X B. 3X C. 4X D. 8X

2X

How much mAs will be generated if the control panel is set at 200 mA and 1/5 second? A. 20 mAs B. 40 mAs C. 80 mAs D. 100 mAs

40 mAs

How will adding filtration affect the primary beam? 1. Increase penetrating quality 2. Decrease x-ray quantity 3. Increase patient skin dose A. 1 & 2 only B. 1 & 3 only C. 2 & 3 only D. 1, 2 & 3

A. 1 & 2 only Beam filtration removes the low energy x-rays in the primary beam, reducing quantity but increasing penetrating quality by producing a beam of mostly high energy x-rays. Low energy x-rays add to patient skin dose, so removing them by adding filtration is a form a radiation protection for the patient.

An underexposed radiograph may be caused by which of the following? 1. Grid cutoff 2. SID too low 3. Grid ratio too low A. 1 only B. 2 only C. 3 only D. 1 & 3 only

A. 1 only

Which of the following CR imaging plates should be selected to produce an image with the best spatial resolution? A. 18 cm x 24 cm (8 x 10) B. 24 cm x 30 cm (10 x 12) C. 30 cm x 35 cm (11 x 14) D. 35 cm x 43 cm (14 x 17)

A. 18 cm x 24 cm (8 x 10)

The SID should be reduced by 1 inch for every _______ degrees of CR angle. A. 5 B. 10 C. 15 D. 20

A. 5

How much should kVp be increased when radiographing a part in a fiberglass orthopedic cast? A. 5 kVp B. 10 kVp C. 15 kVp D. 25 kVp

A. 5 kVp

An image needs to be repeated due to patient motion. If exposure time is decreased, what must be done to the mA in order to maintain the same exposure? A. Increase mA B. Decrease mA C. Keep the mA the same D. Lower mA by half

A. Increase mA

When using AEC, which of the following methods can be used to control motion by reducing exposure time? A. Increase mA B. Decrease kVp C. Increase SID D. Decrease OID

A. Increase mA

How will beam filtration affect the primary beam? A. Make it more homogeneous B. Make it more heterogeneous C. Make it less penetrating D. Reduce its quality

A. Make it more homogeneous

What are the two types of distortion that can reduce the quality of a radiograph? A. Size and shape B. Wide and narrow C. High and low D. Long and short

A. Size and shape

Which of the following will have the greatest effect on reducing motion on an abdomen radiograph? A. Suspend respiration B. Compression device C. Low mA D. Increased SID

A. Suspend respiration

A digital image that is underexposed due to an insufficient amount of mAs would exhibit: A. quantum noise. B. size distortion. C. shape distortion. D. ghosting artifacts

A. quantum noise.

Which of the following causes elongation on an image? A. Part not parallel to the IR B. Central ray not perpendicular to the IR C. X-ray tube not in detent D. Part not in contact with the IR

B. Central ray not perpendicular to the IR

Which of the following affect subject contrast? 1. Part thickness 2. mAs 3. Part density A. 1 & 2 only B. 1 & 3 only C. 2 & 3 only D. 1, 2 & 3

B. 1 & 3 only Subject contrast refers to the difference in tissue density between adjacent anatomical parts. Part thickness, energy of the beam (kVp) and part density will have an effect on how x-rays are absorbed and scattered.

When motion is a problem, time can be reduced by 1/2 if the kVp is increased by what percentage? A. 5% B. 15% C. 25% D. 35%

B. 15%

Which of the following will produce the largest image? A. 40" SID, 3" OID B. 40" SID, 5" OID C. 72" SID, 3" OID D. 72" SID, 5" OID

B. 40" SID, 5" OID

Which of the following radiographic procedures requires a long scale of contrast? A. Lumbar spine B. Chest C. Ribs D. Thoracic spine

B. Chest Rib radiographs should have a short scale of contrast to demonstrate the bones; chest images should have a long scale of contrast to visualize the lungs.

How will increasing the OID affect the spatial resolution on a radiograph? A. Increase spatial resolution B. Decrease spatial resolution C. Eliminate spatial resolution D. Will have no effect on spatial resolution

B. Decrease spatial resolution

How will increasing the focal spot size affect the spatial resolution on a radiograph? A. Increase spatial resolution B. Decrease spatial resolution C. Eliminate spatial resolution D. Will have no effect on spatial resolution

B. Decrease spatial resolution

Saturation in a digital image refers to which of the following? A. Extreme underexposure B. Extreme overexposure C. Excessive quantum mottle D. Excessive distortion

B. Extreme overexposure

A fixed-kVp technique chart uses which of the following? A. Fixed kVp and fixed mAs B. Fixed kVp and variable mAs C. Fixed mAs and variable kVp D. Variable mAs and variable kVp

B. Fixed kVp and variable mAs

Which of the following occurs when the OID is increased? A. Image size is reduced B. Image is magnified C. Image is elongated D. Image is foreshortened

B. Image is magnified

The quality or energy of an x-ray beam is determined by which of the following? A. mAs B. kVp C. SID D. Focal spot size

B. kVp

To avoid shape distortion, which of the following must be paid close attention to? A. SID B. Part angulation C. Part-to-table top distance D. SOD

B. Part angulation

Which of the following factors is the best for reducing the risks of motion? A. Lowest practical mAs B. Shortest possible exposure time C. Lowest ratio grid D. Highest practical kVp

B. Shortest possible exposure time

Modulation transfer function is associated with which of the following? A. Contrast resolution B. Spatial resolution C. Look-up table D. Histogram

B. Spatial resolution Modulation transfer function describes how well an imaging system reproduces an actual object.

Which of the following radiographic qualities determines the sharpness of detail in the finished radiograph? A. Spatial resolution and receptor exposure B. Spatial resolution and distortion C. Receptor exposure and contrast resolution D. Contrast resolution and distortion

B. Spatial resolution and distortion

If the SID is halved, which of the following changes must be made in order to maintain the same exposure? A. mAs halved B. mAs reduced by 4X C. mAs doubled D. mAs increased by 4X

B. mAs reduced by 4X

Sharpness of structural edges will increase when increasing which of the following? 1. SID 2. OID 3. SOD A. 1 only B. 2 only C. 1 & 3 only D. 1, 2 & 3

C. 1 & 3 only

Which of the following will produce the greatest receptor exposure? A. 50 mAs, 80 kVp, 40" SID B. 50 mAs, 80 kVp, 72" SID C. 100 mAs, 80 kVp, 40" SID D. 100 mAs, 80 kVp, 72" SID

C. 100 mAs, 80 kVp, 40" SID

Which of the following techniques will produce the greatest image receptor exposure? A. 100 mA, 0.50 second, 80 kVp B. 200 mA, 0.50 second, 70 kVp C. 300 mA, 0.33 second, 80 kVp D. 400 mA, 0.25 second, 70 kVp

C. 300 mA, 0.33 second, 80 kVp

If the kVp is increased 15%, how much must the mAs be reduced in order to maintain the same receptor exposure? A. 15% B. 25% C. 50% D. 100%

C. 50%

In order to obtain the most spatial resolution the OID should be what? A. The same for every image B. As long as possible C. As short as possible D. Equal to the SID

C. As short as possible

Because digital imaging systems have a wide dynamic range, which of the following is said to be the greatest advantage of digital radiography? A. Fewer repeat exposures B. Spatial resolution C. Contrast resolution D. Less distortion

C. Contrast resolution

Misrepresentation of the true size or shape of an object is the definition of which of the following? A. Spatial resolution B. Elongation C. Distortion D. Magnification

C. Distortion

How will decreasing the focal spot size affect spatial resolution? A. It will increase blur B. It will increase unsharpness C. It will decrease unsharpness D. It will decrease recorded detail

C. It will decrease unsharpness

What is the main reason why beam filters are used in radiography? A. Improves contrast resolution B. Improves spatial resolution C. Reduces patient exposure D. Prolongs tube life

C. Reduces patient exposure

Which of the following may be the cause of an overexposed image? A. mAs too low B. OID too high C. SID too low D. Grid ratio too high

C. SID too low

A flat-panel detector's detector element (DEL) size determines which of the following? A. Dynamic range B. Detective quantum efficiency (DQE) C. Spatial resolution D. Contrast resolution

C. Spatial resolution

Which of the following will occur when the OID is decreased? A. The image will be magnified B. The image will be foreshortened C. The image is closer to actual size D. The image will be elongated

C. The image is closer to actual size

In radiography, an object that is larger than its true size is said to be: A. exaggerated. B. extended. C. magnified. D. intensified.

C. magnified.

The ability of an imaging system to record or capture details (expressed as the number of line pairs per millimeter) is called: A. signal to noise ratio. B. receptor exposure. C. spatial resolution. D. contrast resolution.

C. spatial resolution.

The size of the pixel produced when a CR imaging plate is read depends on which of the following? 1. The speed of the imaging plate as it passes through the reader 2. The frequency with which the data is sampled 3. The dimensions of the laser beam A. 1 only B. 1 & 2 only C. 1 & 3 only D. 1, 2 & 3

D. 1, 2 & 3

Which of the following affect subject contrast? 1. Part thickness 2. kVp 3. Part density A. 1 & 2 only B. 1 & 3 only C. 2 & 3 only D. 1, 2 & 3

D. 1, 2 & 3

Which of the following effects will result from precise collimation? 1. Less biological tissue is exposed 2. Less scatter radiation is produced 3. Radiographic quality is improved A. 1 & 2 only B. 1 & 3 only C. 2 & 3 only D. 1, 2 & 3

D. 1, 2 & 3

Which of the following may be used to control motion during a radiographic examination? 1. Positioning sponges 2. Precise verbal instructions to the patient 3. Shortest possible exposure time A. 1 only B. 1 & 3 only C. 2 & 3 only D. 1, 2 & 3

D. 1, 2 & 3

Which of the following types of information must be on all radiographs? 1. Patient's name 2. Date of exam 3. Right or left markers A. 1 & 2 only B. 1 & 3 only C. 2 & 3 only D. 1, 2 & 3

D. 1, 2 & 3

Why is automatic exposure control (AEC) useful in controlling receptor exposure? 1. Receptor exposure remains constant based on patient thickness 2. AEC shuts off the beam when proper exposure is attained 3. Proper exposure reduces repeat rate A. 1 only B. 1 & 3 only C. 2 & 3 only D. 1, 2 & 3

D. 1, 2 & 3

Which of the following statements is true? 1. A short grayscale has many shades of gray 2. A short grayscale has few shades of gray 3. A short grayscale is high contrast A. 1 only B. 2 only C. 1 & 3 only D. 2 & 3 only

D. 2 & 3 only

If 50 mAs provides an optimum exposure at 40" SID, how much mAs is necessary at 80" SID? A. 12 mAs B. 25 mAs C. 100 mAs D. 200 mAs

D. 200 mAs

Which of the following distances (SID) would produce the least distortion? A. 40" B. 55" C. 60" D. 72"

D. 72"

Density was the term used to describe the overall blackening of a film-screen radiograph. What term is used in digital imaging to describe this radiographic quality? A. Window width B. Exposure C. Contrast D. Receptor exposure

D. Receptor exposure

Motion has the greatest effect on which of the following? A. Distortion B. Receptor exposure C. Contrast resolution D. Spatial resolution

D. Spatial resolution

Which of the following is the most important factor in controlling size distortion? A. Focal spot size B. SID C. OID D. Exposure time

OID

Which of the following will have the greatest effect on size distortion? A. SID B. OID C. Focal spot size D. Image size

OID

Which of the following is NOT one of the three elements that affect shape distortion? A. Central ray B. SID C. Object D. Image receptor

SID

Which of the primary factors will always have an effect on spatial resolution? A. Seconds B. SID C. mA D. kVp

SID

Which of the following would describe the amount of detail in a digital image? A. Contrast resolution B. Receptor exposure C. Spatial resolution D. Magnification ratio

Spatial resolution

What is the correct name for the loss of sharpness due to the use of a large focal spot? A. Umbra B. Mottle C. Blur D. Unsharpness

Unsharpness

Because of the anode heel effect, where is the intensity of the x-ray beam the greatest? A. At the anode end B. At the cathode end C. At the rotor end D. In the center of the beam

at the cathode end

How will an increase in radiographic fog affect contrast? A. Contrast will be higher B. Contrast will be lower C. Contrast will be eliminated D. Contrast will remain the sam

contrast will be lower

If the mA is increased, how must the time be changed in order to maintain the same receptor exposure? a) increased d) decreased c) doubled d) reduced by half

decreased

Changing the shape of an object is called what? A. Magnification B. Distortion C. Minification D. Definition

distortion

If the exposure time is cut in half, how must the mA be adjusted to maintain the same receptor exposure? A. Cut in half B. Reduced 2 times C. Doubled D. Increased 4 times

doubled

Spatial resolution can be improved by reducing which of the following? A. SID B. SOD C. Focal spot size D. Patient size

focal spot size

If the central ray is perpendicular to the image receptor, but the part is angled, what will be the result? A. Foreshortening B. Elongation C. Minification D. Magnification

foreshortening

How would an image with just a few shades of gray be described? A. High spatial resolution B. Low spatial resolution C. High contrast D. Low contrast

high contrast high contrast means there is a big difference between light and dark areas

Subject contrast will be the lowest with which of the following body types? A. Sthenic B. Asthenic C. Hyposthenic D. Hypersthenic

hypersthenic

If it is impossible to get the part close to the image receptor, what can be done to compensate? A. Increase exposure time B. Increase SID C. Decrease kVp D. Decrease mA

increase SID

Which of the following will keep size distortion to a minimum? A. Increase kVp B. Increase grid ratio C. Increase SID D. Increase focal spot size

increase SID

Spatial resolution is NOT affected by which of the following? A. SID B. SOD C. OID D. kVp

kVp

The quantity of x-rays produced is dependent upon which of the following? A. mAs B. SID C. OID D. SOD

mAs

Spatial resolution can be improved by which of the following? A. Maximum OID B. Maximum SID C. Minimum SID D. Minimum SOD

maximum SID

How well an imaging system reproduces the actual object is referred to as what? A. Modulation transfer function B. Resolving power C. Lines per inch D. Linear image transfer

modulation transfer function

Which of the following conditions would be considered "hard to penetrate"? A. Emphysema B. Osteoporosis C. Osteosclerosis D. Pneumothorax

osteosclerosis

Each cell of an image matrix is called what? A. A square B. A pixel C. An element D. A byte

pixel

Which of the following occurs when the imaging plate or flat-panel detector is grossly overexposed? A. Saturation B. Intensification C. Dynamic quantum D. Dynamic inefficiency

saturation

Spatial resolution can be improved by which of the following? A. Adjusting kVp B. Adjusting mAs C. Selecting the small focal spot D. Using the air gap technique

selecting the small focal spot

Which of the following will occur when the tube angle is decreased? A. The image will be foreshortened B. The image will be elongated C. Shape distortion will decrease D. Size distortion will increase

shape distortion will decrease

The measure of the amount of detail in a digital image defines which of the following? A. Brightness B. Spatial resolution C. Distortion D. Contrast resolution

spatial resolution

Which of the following statements would define spatial resolution in digital imaging? A. The contrast in an image B. The lack of distortion in an image C. The measure of the amount of detail in an image D. The number of gray tones in an image

the measure of the amount of detail in an image