Spring 25: Exam 2

Question 1

Which sequence of events is correct concerning the production of a PSL signal?
Incorrect

A. Stimulate, expose, read, erase
B. Erase, stimulate, read, expose
C. Read, erase, stimulate, expose
D. Expose, stimulate, read, erase

Answer 1

D. Expose, stimulate, read, erase

Question 2

What takes place during the expose step in the production of a PSL signal?

A. The latent image is stimulated from the interactions of an infrared laser beam with the PSP
B. Residual metastable electrons are moved to the ground state by an intense light
C. The emitted light signal is detected and measured
D. An energy transfer results from the excitation of electrons into a metastable state

Answer 2

D. An energy transfer results from the excitation of electrons into a metastable state

Question 3

What takes place during the read step in the production of a PSL signal?

A. The latent image is stimulated from the interactions of an infrared laser beam with the PSP
B. The emitted light signal is detected and measured
C. An energy transfer results from the excitation of electrons into a metastable state
D. Residual metastable electrons are moved to the ground state by an intense light

Answer 3

B. The emitted light signal is detected and measured

Question 4

Which of the following are considered a source of image noise in computed radiography?

A. Fast or slow scan driver
B. Scatter of stimulating beam
C. Inadequate sampling
D. All of the options

Answer 4

C. Inadequate sampling

Question 5

The emission of visible light after excitation by laser light is known as ________________.

A. refraction
B. reflection
C. photoelectric absorption
D. photostimulation

Answer 5

D. photostimulation

Question 6

Which of the following material(s) is/are considered photostimulable?

A. Lithium fluoride
B. Thermoluminescent dosimetry
C. Barium fluorohalide
D. All of the options

Answer 6

C. Barium fluorohalide

Question 7

What takes place during the erase step in the production of a PSL signal?

A. The emitted light signal is detected and measured.
B. Residual metastable electrons are moved to the ground state by an intense light.
C. The latent image is stimulated from the interactions of an infrared laser beam with the PSP.
D. An energy transfer results from the excitation of electrons into a metastable state.

Answer 7

B. Residual metastable electrons are moved to the ground state by an intense light.

Question 8

What takes place during the stimulate step in the production of a PSL signal?

A. Residual metastable electrons are moved to the ground state by an intense light.
B. The emitted light signal is detected and measured.
C. An energy transfer results from the excitation of electrons into a metastable state.
D. The latent image is stimulated from the interactions of an infrared laser beam with the PSP.

Answer 8

D. The latent image is stimulated from the interactions of an infrared laser beam with the PSP.

Question 9

Which of the following is the principal source of noise on a radiographic image?

A. Scatter radiation
B. Motion
C. Artifacts

Answer 9

A. Scatter radiation

Question 10

What are the principal characteristics of any medical image?

A. Spatial resolution, noise, optical density, and absorption
B. Contrast resolution, noise, artifacts, and spatial resolution
C. Noise, artifacts, optical density, and spatial resolution
D. Absorption, spatial resolution, noise and artifacts

Answer 10

B. Contrast resolution, noise, artifacts, and spatial resolution

Question 11

Which of the following are capture elements used in DR?

A. Cesium iodide
B. Sodium iodide
C. Gadolinium oxysulfide
D. All of the options

Answer 11

C. Gadolinium oxysulfide

Question 12

Which of the following are coupling elements used in DR?

A. Gadolinium oxysulfide
B. Fiber-optic assembly
C. Sodium iodide
D. Cesium iodide

Answer 12

B. Fiber-optic assembly

Question 13

Which of the following are collection elements used in DR?

A. Thin-film transistor
B. Charge-coupled device
C. Photodiode
D. All of the options

Answer 13

C. Photodiode

Question 14

What are the principal advantages of a charge-coupled device?

A. Sensitivity, response time, dynamic range
B. Size, resolution, decreased noise
C. Dynamic range, size, and sensitivity
D. Decreased noise, sensitivity and size

Answer 14

C. Dynamic range, size, and sensitivity

Question 15

The ability of the CCD to detect and respond to very low levels of visible light is known as ________________.

A. resolution
B. spatial resolution
C. sensitivity
D. dynamic range

Answer 15

C. sensitivity

Question 16

Which of the following is an indirect DR process by which x-rays are converted first to light and then to an electronic signal?

A. Amorphous selenium (a-Se)
B. Cesium iodide/charge coupled device (CsI/CCD)
C. Sodium iodide (NaI)
D. Gadolinium oxysulfide/amorphous selenium (GdOS/a-Si)

Answer 16

B. Cesium iodide/charge coupled device (CsI/CCD)

Question 17

Digital radiography is best described by which three elements?

A. Confine, coupling, contain
B. Collection, combining, capture
C. Collection, capture, coupling
D. Capture, catch, collection

Answer 17

C. Collection, capture, coupling

Question 18

The ability of the CCD to respond to a wide range of light intensity, from very dim to very bright is known as ________________.

A. spatial resolution
B. resolution
C. sensitivity
D. dynamic range

Answer 18

D. dynamic range

Question 19

Which of the following is a direct DR process by which x-rays are converted to an electronic signal?
Correct

A. Amorphous selenium (a-Se)
B. Cesium iodide/amorphous silicon (CsI/a-Si)
C. Gadolinium oxysulfide/amorphous selenium (GdOS/a-Si)
D. Cesium iodide/charge coupled device (CsI/CCD)

Answer 19

A. Amorphous selenium (a-Se)

Question 20

Spatial resolution in DR is limited by ___________.

A. pixel size
B. monitor brightness
C. charge coupled device
D. thin-film transistor

Answer 20

A. pixel size

Question 21

With digital imaging, patient dose can be reduced by using higher ______ techniques.

A. optical density
B. mAs
C. contrast
D. kVp

Answer 21

D. kVp

Question 22

The use of an image receptor with _____ DQE can result in _____ patient doses.

A. high; lower
B. high; higher
C. low; higher
D. low; lower

Answer 22

A. high; lower

Question 23

_________ is the ability to render small objects on the image.

A. Spatial resolution
B. Contrast resolution
C. Brightness
D. Dynamic range

Answer 23

A. Spatial resolution

Question 24

_________ is the ability to distinguish many shades of gray from black to white.

A. Spatial resolution
B. Dynamic range
C. Brightness
D. Contrast resolution

Answer 24

D. Contrast resolution

Question 25

DQE is __________________. A. detective quantum efficiency B. detective quantum energy C. direct quantum efficiency D. density quantum effect

Answer 25

A. detective quantum efficiency

Question 26

If an image receptor has a high probability of interacting with the x-ray beam, then it has a high _______. A. DQE B. SNR C. lp/mm D. MTF

Answer 26

A. DQE

Question 27

Digital radiography images should be repeated if there is a problem with _________. A. brightness B. overexposure C. contrast D. positioning

Answer 27

D. positioning

Question 28

________ and ___________ are the two most important characteristics of an imaging modality. A. Spatial frequency; modulation transfer function B. Modulation transfer function; spatial resolution C. Spatial resolution; contrast resolution D. Contrast resolution; spatial frequency

Answer 28

C. Spatial resolution; contrast resolution

Question 29

_________ is the number of gray shades that an imaging system can reproduce. A. Contrast resolution B. Spatial resolution C. Brightness D. Dynamic range

Answer 29

D. Dynamic range

Question 30

Which of the following is a measure of x-ray absorption efficiency? A. Modulation transfer function B. Dynamic range C. Contrast resolution D. Detective quantum efficiency (DQE)

Answer 30

D. Detective quantum efficiency (DQE)

Question 31

What is the process of assigning a value to a dead pixel based on the recorded values of adjacent pixels? A. Flatfielding B. Rough handling C. Interpolation D. Pixel failure

Answer 31

C. Interpolation

Question 32

Which type of compression is up to 3:1 and is generally considered acceptable and helpful in digital radiographic image management? A. Lousy compression B. Lossless compression C. Lazy compression D. Lossy compression

Answer 32

B. Lossless compression

Question 33

Which type of compression is greater than 10:1 and supports teleradiology but not CAD? A. Lousy compression B. Lossy compression C. Lazy compression D. Lossless compression

Answer 33

B. Lossy compression

Question 34

Which of the following is a unique artifact for digital radiographic image receptors? A. Scratches B. Rough handling C. Pixel failure D. Dust

Answer 34

C. Pixel failure

Question 35

What is a preprocessing software correction that is performed to equalize the response of each pixel to a uniform x-ray beam? A. Flatfielding B. Image compression C. Pixel failure D. Interpolation

Answer 35

A. Flatfielding

Question 36

A graph of frequency of occurrence versus digital value intervals is known as ___________. A. flatfielding B. histograms C. image compression D. interpolation

Answer 36

B. histograms

Question 37

The process, known as ______________, allows two or more images to be projected on a single image receptor. A. image compression B. flatfielding C. histograms D. partitioning

Answer 37

D. partitioning

Question 38

If at least three edges of the image receptor are not identified, all data, including raw exposure or scatter outside the field may be included in the histogram, and this will result in which type of error? A. Histogram analysis error B. Interpolation C. Flatfielding D. Image compression

Answer 38

A. Histogram analysis error

Question 39

What can be done to prevent histogram errors that can lead to artifacts? A. Proper collimation and compression B. Proper centering and compression C. Proper centering and automatic exposure control D. Proper collimation and centering

Answer 39

D. Proper collimation and centering

Question 40

This results from a gradual patient exposure increase over time after digital IR's replace conventional systems

Answer 40

Dose creep

Question 41

What was the first company to develop a CR system?

Answer 41

Kodak

Question 42

What is Scanned Projection Radiography? (SPR)

Answer 42

X-ray tube and detector array are stationary - move together in unison.

Question 43

Picture element that is a visual representation of digital data

Answer 43

Pixel

Question 44

This determines dynamic range

Answer 44

pixel bit depth

Question 45

Sharpness of the structural lines on an image

Answer 45

Recorded detail

Question 46

Sharpness of the structural edges on an image

Answer 46

Spatial Resolution

Question 47

Range of exposures a system can record to create a visible image (the # of gray shades that can be represented)

Answer 47

Dynamic Range

Question 48

1024 x 1024

Answer 48

DR Matrix size

Question 49

2048 x 2048

Answer 49

CR Matrix size

Question 50

4096 x 4096

Answer 50

CR Matrix size

Question 51

2 types of Direct Readout Digital Radiography (DR)

Answer 51

1. Charge-Coupled Device (CCD) 2. Flat Panel System

Question 52

2 types of flat panel systems

Answer 52

1. indirect capture 2. direct capture

Question 53

Flat panel system that: -uses scintillator to convert radiation into visible light -emitted light converted to electronic charge -electronic charge stored in TFT array (a-Si) -TFT sends electronic signals to amplifiers -amplifiers send signals to analog-to-digital converter

Answer 53

Indirect Capture

Question 54

Flat Panel System that: -is comprised of TFT matrix array with a-Se -NO scintillation/light conversion required -converts 100% of x-ray energy into electrical energy

Answer 54

Direct Capture

Question 55

What is the scintillator made of?

Answer 55

Cesium Iodine

Question 56

When was CR clinically introduced?

Answer 56

1982 by Fuji

Question 57

Pediatric patients are ______ times more sensitive to ionizing radiation than adults.

Answer 57

10

Question 58

At least ______ of the plate must be exposed to avoid a rescaling error in CR.

Answer 58

25%

Question 59

How bright/dark the image is

Answer 59

Window level

Question 60

The ratio of black & white/contrast

Answer 60

Window width

Question 61

The _____ the window, the _____ the contrast A. wider; higher B. narrower; higher C. wider; lower D. narrower; lower

Answer 61

C. wider; lower

Question 62

Over-sensitization of a chemical within the eye resulting in a temporary white light blindness

Answer 62

Veil glare

Question 63

1. expose 2. stimulate 3. read 4. erase

Answer 63

CR plate viewing

Question 64

1. capture 2. coupling 3. collection

Answer 64

DR viewing