Deck 6: Image Receptors and Image Acquisition

Question 1

What is the term specifically used to describe the emission of light during and after stimulation by radiation?

A) Luminescence
B) Phosphorescence
C) Fluorescence
D) Incandescence

Answer 1

Phosphorescence

Question 2

What influences the speed of radiographic film?

A) The amount of silver halide crystals in the emulsion
B) The color of the dye added to the film base
C) The size of the silver halide crystal
D) A and C

Answer 2

A and C

Question 3

What is the outermost layer of radiographic film called?

A) Emulsion
B) Supercoat
C) Base
D) Gelatin

Answer 3

Supercoat

Question 4

What is the effect of the presence of a dye in the phosphor layer of the intensifying screen?

A) Decreased speed, increased recorded detail, and increased patient dose
B) Decreased speed, increased recorded detail, and decreased patient dose
C) Increased speed, decreased recorded detail, and increased patient dose
D) Increased speed, decreased recorded detail, and decreased patient dose

Question 5

What is the purpose of the intensifying screen?

A) To decrease the production of scatter radiation
B) To reduce the amount of scatter striking the film
C) To reduce the amount of exposure to the patient
D) B and C

Question 6

The CR latent image consists of:

A) Electrons trapped in the phosphor layer
B) Clumps of metallic silver in the emulsion
C) Light trapped in the phosphor layer
D) The image as seen on the display monitor

Question 7

What is the effect of the presence of a reflective layer within the intensifying screen?

A) Increased speed, increased recorded detail, and increased patient dose
B) Decreased speed, increased recorded detail, and decreased patient dose
C) Increased speed, decreased recorded detail, and increased patient dose
D) Increased speed, decreased recorded detail, and decreased patient dose

Question 8

What is the term generally used to describe the emission of light from a substance as the result of stimulation by radiation?

A) Luminescence
B) Phosphorescence
C) Fluorescence
D) Incandescence

Question 9

Which layer of the intensifying screen is the furthest from the film?

A) Base
B) Reflective layer
C) Phosphor layer
D) Adhesive

Question 10

What are the physical imperfections in the emulsion layer of radiographic film called?

A) Rare earth phosphors
B) Calcium tungstate
C) Sensitivity specks
D) Silver halide crystals

Question 11

When a film has emulsion coated on both sides of the base versus one side of the base, the film is referred to as:

A) Single emulsion film
B) Double emulsion film
C) Triple emulsion film
D) None of the above

Question 12

The CR phosphor layer is composed of:

A) Gadolinium oxysulfide with terbium
B) Barium fluorohalide with europium
C) Lanthanum oxybromide with thulium
D) Yttrium oxysulfide with terbium

Question 13

Which layer of the intensifying screen is closest to the film?

A) Protective layer
B) Base
C) Phosphor layer
D) Emulsion

Question 14

The front or tube side of radiographic cassettes should be made of a material that:

A) Absorbs most of the x-ray beam
B) Reduces scatter production
C) Filters the beam
D) Absorbs very little of the x-ray beam

Question 15

The DR detector array is typically located:

A) Inside the cassette
B) By the computer keyboard
C) On top of the table
D) Where you would normally find the Bucky tray

Question 16

What is achieved when the color of light emitted by an intensifying screen matches the color of light a film responds to?

A) Chromatic spectrometry
B) Orthochromatic sensitivity
C) Panchromatic matching
D) Spectral matching

Question 17

How much of the x-ray beam do rare earth phosphor intensifying screens absorb?

A) 5%
B) 30%
C) 60%
D) 90%

Question 18

What is the term used to describe the color of light to which a radiographic film is sensitive?

A) Chromatic spectrometry
B) Orthochromatic sensitivity
C) Panchromatic matching
D) Spectral sensitivity

Question 19

What is the term specifically used to describe the emission of light during x-ray stimulation only?

A) Luminescence
B) Phosphorescence
C) Fluorescence
D) Incandescence

Question 20

Increasing the thickness of the intensifying screen phosphor layer:

A) Increases speed, increases recorded detail, and increases patient dose
B) Decreases speed, increases recorded detail, and decreases patient dose
C) Increases speed, decreases recorded detail, and increases patient dose
D) Increases speed, decreases recorded detail, and decreases patient dose

Question 21

The distance between the middle of two adjacent pixels is the:

A) Sampling frequency
B) Sampling pitch
C) Pixel frequency
D) Pixel pitch

Question 22

With CR, when the x-ray photons are absorbed by the phosphor, the ___________ atoms become ionized.

A) Barium fluorohalide
B) Tungsten
C) Europium
D) Silver halide

Question 23

Which of the following is not a component of the CR IP?

A) Emulsion layer
B) Support layer
C) Phosphor layer
D) Protective layer

Question 24

The Gurney-Mott theory is associated with:

A) CR latent image formation
B) Film latent image formation
C) DR latent image formation
D) Rare-earth phosphor intensifying screens

Question 25

Which of the following is not part of a CR reader unit?

A) Optical system
B) ADC
C) Photodetector
D) Developer tank

Question 26

The _____________ collects, amplifies and converts visible light to an electrical signal.

A) ADC
B) PMT
C) PSP
D) PSST

Question 27

This material is composed of barium fluorohalide and makes up the primary component of the CR IP.

A) Luminescence
B) Photostimulable phosphor
C) Photostimulable luminescence
D) None of the above

Question 28

With a fixed matrix CR reader system, changing to a larger IP, for the same FOV, will result in:

A) Larger pixels
B) Smaller pixels
C) Improved spatial resolution
D) B and C

Question 29

The emission of light when stimulated by a high intensity laser beam is:

A) Luminescence
B) Photostimulable phosphor
C) Photostimulable luminescence
D) None of the above

Question 30

With CR, trapped electrons are:

A) Proportional in number to the tissue's x-ray absorption
B) In a lower energy state
C) Released during the readout stage
D) A and C

Question 31

In the CR reader unit, the IP is scanned with a(n):

A) PMT
B) Electron gun
C) Helium-neon laser beam
D) PSP

Question 32

With CR, a higher sampling pitch results in _____________ pixel size and ____________ spatial resolution.

A) Increased; increased
B) Increased; decreased
C) Decreased; increased
D) Decreased; decreased

Question 33

Pixel bit depth is determined by the:

A) ADC
B) FOV
C) Matrix
D) Tissue type

Question 34

DR imaging systems briefly store the electrical charge in the:

A) ADC
B) TFT
C) CRT
D) EST

Question 35

_______________ can be removed from the Bucky and used on the tabletop or a stretcher.

A) Full panel digitizer
B) Flat-panel detector
C) Folding pixel detector
D) Failure to properly digitize

Question 36

The distance between the analog points being sampled is the:

A) Sampling frequency
B) Sampling pitch
C) Pixel frequency
D) Pixel pitch

Question 37

The CR system's ability to display a range of shades of gray is determined by its:

A) Pixel pitch
B) Pixel size
C) Pixel depth
D) Matrix

Question 38

With CR, a higher sampling frequency results in _____________ pixel size and ____________ spatial resolution.

A) Increased; increased
B) Increased; decreased
C) Decreased; increased
D) Decreased; decreased

Question 39

Immediately before leaving the CR reader unit, the IP is exposed to:

A) The laser light
B) Developer chemicals
C) Intense white light
D) X-rays

Question 40

How often the analog signal is digitized is the:

A) Sampling frequency
B) Sampling pitch
C) Pixel frequency
D) Pixel pitch

Question 41

With an FPD, electrical charges from each DEL are read out separately.

Question 42

An image with high SNR will have decreased detail visibility.

Question 43

Which of the following is not a component of a flat-panel detector?

A) TFT array
B) X-ray converter
C) Glass substrate
D) Phosphor layer

Question 44

Overexposing a digital image receptor may result in a quality image, but:

A) Quantum noise will be visible.
B) The SNR will be poor.
C) The ALARA principle has not been followed.
D) The system will not last as long as expected.

Question 45

Because digital imaging has a large dynamic range, significantly lower than necessary x-ray exposure will still result in a quality image.

Question 46

Once the data is in digital format, there is no difference between image processing and display between CR and DR.

Question 47

The quality of the CR latent image will remain the same for up to 6 hours after exposure.

Question 48

Exit radiation is converted to visible light with the direct conversion detector.

Question 49

The DR system does not require a separate reader unit.

Question 50

A high SNR means that the:

A) Signal strength is high.
B) Signal strength is low.
C) Noise is high.
D) B and C

Question 51

The ability of the detector to accurately capture the variety of photon intensities in the remnant radiation is:

A) Pixel depth
B) Dynamic range
C) ALARA
D) Pixel sensitivity

Question 52

The dynamic range of a digital imaging system is significantly larger than a film-screen system.

Question 53

Both CR and DR are electronic detectors that combine image capture and image readout.

Question 54

The indirect conversion detector uses:

A) A scintillator
B) A photodetector
C) Amorphous selenium
D) A and B

Question 55

There is no light produced with CR when radiation it interacts with the IP.

Question 56

The ____________ array is divided into square detector elements (DEL).

A) ADC
B) IP
C) TFT
D) SNR