Deck 8: Digital Image Receptor Systems

Question 1

A "cassette-based" digital imaging system is termed:

A) digital radiography (DR).
B) computed radiography (CR).
C) direct conversion.
D) indirect conversion.

Answer 1

computed radiography (CR).

Question 2

When using indirect conversion DR systems,the light in the flat-panel detector is converted to an electric signal by the:

A) scintillator.
B) photodiode.
C) thin-film transistor.
D) detector matrix.

Answer 2

photodiode.

Question 3

When using DR systems,indirect conversion of x-ray energy requires how many steps?

A) One
B) Two
C) Three
D) Four

Answer 3

Two

Question 4

Which of the following should be used when imaging body parts that have extreme differences in tissue thickness?

A) Larger IR
B) Shorter SID
C) Larger focal spot
D) Compensating filter

Question 5

Which of the following is important to use when using digital systems for mobile radiography?

A) Filter
B) Grid
C) kVp less than 90
D) Foam pad under the body part

Question 6

After the imaging plate is scanned in the CR reader and the image sent to storage,the phosphor is exposed to a _________ to erase the anatomical image.

A) white light
B) laser beam
C) electric current
D) electric charge

Question 7

What is the size of the flat-panel detector inside the table of a DR system?

A) 10 × 12 in.
B) 14 × 14 in.
C) 14 × 17 in.
D) 17 × 17 in.

Question 8

How many times can the phosphor in the CR plate be used?

A) 1,200 times
B) 5,000 times
C) 8,000 times
D) 10,000 times

Question 9

Quantum mottle occurs in digital images if:

A) the time is set too long.
B) the mA is set too high.
C) the kVp is set too high.
D) there are not enough photons reaching the IR.

Question 10

When a CR plate is inserted into the reader for processing,the phosphor is scanned with a:

A) green/blue light.
B) fluorescent light.
C) white light.
D) laser beam.

Question 11

Which of the following must be used with digital-based x-ray processors to ensure that the ALARA concept is practiced?

A) A grid
B) A 40-inch SID
C) An exposure technique chart
D) Added aluminum at the port of the x-ray tube

Question 12

The purpose of the photostimulable phosphor plate is to:

A) remove the images during processing.
B) erase the images after processing.
C) store the image of the body part until processed.
D) serve as the archive for digital images.

Question 13

When splitting a CR cassette in half for two exposures,the half not being exposed should be covered with:

A) lead.
B) aluminum.
C) dark paper.
D) white paper.

Question 14

The system used to view and store digital x-ray images is called a ______ system.

A) CR
B) DR
C) PACS
D) postprocessing

Question 15

A minimum of how many sides of the collimated x-ray beam should be shown on the IR and image?

A) One
B) Two
C) Three
D) Four

Question 16

The storage phosphors in the CR plate are hypersensitive to:

A) small levels of scatter radiation exposure.
B) large levels of scatter radiation exposure.
C) low kVp or low mA settings.
D) incandescent or fluorescent room light.

Question 17

The front of the imaging plate is made of:

A) plastic.
B) carbon.
C) a radiolucent material that does not absorb x-rays.
D) a radiolucent material that absorbs x-rays.

Question 18

Which of the following is a true statement regarding the centering of the body part when using digital systems?

A) The part must be placed off-center by about 2 cm.
B) The part must be placed in the center of the plate or detector.
C) The part should be placed near one of the four edges.
D) The part can be placed anywhere on the plate or detector.

Question 19

Barium fluorohalide with europium is used:

A) in the CR reader to erase the image.
B) in the CR reader to remove the image and process it.
C) as the phosphor that absorbs the x-ray energy in the imaging plate.
D) as the phosphor that absorbs the x-ray energy in the flat-panel detector.

Question 20

One of the main advantages of using CR and DR digital systems is:

A) reduction in repeat exams.
B) lower dose to the patient.
C) ability to process images very fast.
D) ability to see greater resolution.

Question 21

The computer software function that allows any type of "text" to be written on a radiographic image is:

A) window width.
B) window level.
C) image annotation.
D) image stitching.

Question 22

The number of gray shades that a digital system can reproduce is termed:

A) quantum mottle.
B) dynamic range.
C) contrast resolution.
D) spatial resolution.

Question 23

Direct conversion DR processing requires how many steps to process the x-ray image?

A) One
B) Two
C) Three
D) Four

Question 24

Digital imaging processors replace which components in the x-ray department?
1) Darkroom
2) Film/screen cassettes
3) Generator

A) 1 and 2
B) 1 and 3
C) 2 and 3
D) 1, 2, and 3

Question 25

Which of the following should never be placed on the radiographic image using electronic means (computer software)?

A) Diagnosis
B) Patient's age
C) Patient's name
D) R and L markers

Question 26

Which control on the viewing station controls the density,or brightness,in the radiographic image?

A) Window width
B) Window level
C) Shuttering
D) Dynamic range

Question 27

"Window width" controls which aspect of the radiographic image?

A) Shuttering
B) Noise
C) Density
D) Contrast

Question 28

The ability to distinguish anatomical structures of similar subject contrast is termed:

A) quantum mottle.
B) dynamic range.
C) contrast resolution.
D) spatial resolution.

Question 29

"Noise" refers to the amount of information that is not useful in the radiographic image. This noise is referred to as:

A) quantum mottle.
B) shuttering.
C) dynamic range.
D) signal-to-noise ratio (SNR).

Question 30

The ability of the digital system to convert the x-ray input electric signal into a useful radiographic image is termed the:

A) dynamic range.
B) contrast resolution.
C) signal-to-noise ratio (SNR).
D) shuttering.

Question 31

What is the name of the computer software function that allows separate radiographic images to be tied into one image for viewing?

A) Shuttering
B) Image stitching
C) Window level
D) Window width

Question 32

Each square picture element in a digital viewing monitor is called a:

A) voxel.
B) pixel.
C) matrix.
D) window level.

Question 33

A charge-coupled device (CCD)is used in an indirect conversion DR system to:

A) convert x-rays into a light.
B) convert light into an electrical signal.
C) allow readout of the x-ray image.
D) store the x-ray image.

Question 34

Which control on the viewing station can blacken the clear or white areas around the collimation edges of a radiograph?

A) Shuttering
B) Image stitching
C) Window width
D) Window level

Question 35

The best quality radiographic image will be produced on the viewing monitor when there is _____ SNR,_____ noise.

A) low; high
B) low; low
C) high; high
D) high; low

Question 36

A matrix of 1200 × 1800 will show how many pixels on the viewing monitor?

A) 2,160,000
B) 2,800,000
C) 4,160,000
D) 4,1 60,000

Question 37

Which of the following matrix sizes will produce the best spatial resolution?

A) 500 × 1,000 matrix
B) 1,000 × 1,000 matrix
C) 2,000 × 2,000 matrix
D) 3,000 × 3,000 matrix

Question 38

The amount of detail or sharpness in the digital image is termed:

A) contrast resolution.
B) dynamic range.
C) recorded detail.
D) spatial resolution.

Question 39

The viewing monitor's active viewing area is called a:

A) voxel.
B) pixel.
C) matrix.
D) window width.

Question 40

The greatest spatial resolution will be produced when the matrix is _____ and the pixels are _____.

A) small; large
B) small; small
C) large; small
D) large; large

Question 41

Which radiographic examination would require "image stitching" of several separate images?

A) The leg
B) All femur radiographs
C) Full-spine for scoliosis
D) Abdomens on patients taller than 6 feet

Question 42

Which of the following artifacts can appear in the radiographic image if the CR imaging plate is not erased properly?

A) Light spots
B) Edge enhancement
C) Quantum mottle
D) Phantom or ghost images

Question 43

What is the weakest link in the digital imaging chain?

A) CR reader
B) Postprocessing software
C) Viewing monitor
D) DICOM server

Question 44

A CR plate inside the cassette can be exposed to light for how long before it will start to erase?

A) 10 seconds
B) 15 seconds
C) 20 seconds
D) 25 seconds

Question 45

What is the name of the computer software function that allows adjustment of the radiographic image after it has been processed?

A) Image annotation
B) Postprocessing
C) Edge enhancement
D) DICOM gray-scale function

Question 46

The artifact that will occur when the grid lines are not aligned with the CR reader's laser light is:

A) quantum mottle.
B) Moire pattern.
C) ghost images.
D) light spots.

Question 47

Which of the following artifacts can occur if the CR imaging plate receives too much background or scatter radiation?

A) Fogging
B) Ghost or phantom images
C) Light spots
D) Quantum mottle

Question 48

The artifact that is caused by noise in the digital system's electronics,and creates lengthwise or crosswise lines,is called a(n):

A) Moire pattern.
B) ghost image.
C) scratch or tear.
D) extraneous line pattern.

Question 49

Which of the following tells the operator that the correct exposure has been received by the phosphors in the imaging plate?

A) Exposure indicator number
B) Signal-to-noise ratio (SNR)
C) Health level-7
D) DICOM gray-scale function

Question 50

What artifact will be shown in the radiographic image if there is inadequate exposure technique?

A) Quantum mottle
B) Moire pattern
C) Ghost images
D) Light spots

Question 51

When there is foreign matter inside the CR imaging plate,an artifact may be shown called:

A) quantum mottle.
B) Moire pattern.
C) light spots.
D) extraneous line patterns.

Question 52

Which standard ensures that all the different information systems within a given hospital or clinic can communicate effectively?

A) DICOM
B) Health level-7
C) ALARA
D) SMPTE

Question 53

What is the term for the calibration of an image display system that ensures that all radiographic images' gray scales are presented consistently?

A) Postprocessing
B) Edge enhancement
C) Health level-7
D) DICOM gray-scale function

Question 54

Which of the following should be checked regularly on the viewing monitor?
1) Viewing surface and air flow
2) Image quality using a test pattern
3) Resolution

A) 1 and 2
B) 1 and 3
C) 2 and 3
D) 1, 2, and 3

Question 55

The universally accepted standard for exchanging radiographic images inside and outside the institution,and among all manufacturers,is which of the following?

A) DICOM
B) Health level-7
C) DICOM gray-scale function
D) ALARA

Question 56

Digital radiographic images are stored,retrieved,sent,and viewed using an extensive image management system called the:

A) Health level-7.
B) SMPTE.
C) PACS.
D) DICOM.

Question 57

One of the most important aspects of setting the exposure factors when using digital systems is to ensure that the:

A) grid is used.
B) SID is set correctly.
C) mAs is set correctly.
D) kVp is set correctly.

Question 58

What is the name of the processing technique that can be used to increase contrast and sharpen the image?

A) Contrast resolution
B) DICOM gray-scale function
C) Edge enhancement
D) Image annotation