Chapter 4 - 3

Question 1

69. Which of the following changes in the exposure indicator values does NOT represent a doubling of radiation exposure to the IR?

a. S number (Fuji) changing from 200 to 400
b. S number (Fuji) changing from 400 to 200
c. EI (Carestream) changing from 1200 to 1500
d. EI (Carestream) changing from 1500 to 1800

Answer 1

a. S number (Fuji) changing from 200 to 400

In that the S number is inversely related to exposure to the IR, changing from 200 to 400 indicates that the IR was exposed to one half the amount of radiation exposure.
REF: p.89

Question 2

70. Which of the following exposure indicators has an inverse relationship with exposure to the IP?

a. EI (Carestream)
b. IgM (Agfa)
c. S number (Fuji)
d. All have an inverse relationship.

Answer 2

c. S number (Fuji)

Fuji’s S number has an inverse relationship with IP exposure. The higher the S number, the lower the exposure to the IR.
REF: p.89

Question 3

71. A value that reflects the difference between the desired or target exposure to the IR and the actual exposure to the IR is the:

a. EI (Carestream).
b. IgM (Agfa).
c. S number (Fuji).
d. deviation index (DI).

Answer 3

d. deviation index (DI).

The DI is created as a standard exposure indicator and is a value that reflects the difference between the desired or target exposure to the IR and the actual exposure to the IR.
REF: p.90

Question 4

72. The __________ provides a method of altering the image to change the display of the digital image.

a. histogram
b. lookup table
c. exposure indicator
d. matrix

Answer 4

b. lookup table

The lookup table allows alteration of the digital image to display it differently.
REF: p.90

Question 5

73. Because digital IRs have a linear exposure response and wide dynamic range, raw data images appear:

a. very bright.
b. very dark.
c. with low contrast.
d. with high contrast.

Answer 5

c. with low contrast.

All raw data, ranging from very low to very high exposures, result in an image with very low contrast.
REF: p.90

Question 6

74. Soft copy viewing means that the image is being viewed:

a. at a computer.
b. on a soft piece of film.
c. in a soft light environment.
d. none of the above.

Answer 6

a. at a computer.

Soft copy viewing means that the image is being viewed on a computer monitor.
REF: p.93

Question 7

75. A CRT type monitor:

a. has a fluorescent screen.
b. uses an electron gun.
c. scans in lines.
d. all of the above.

Answer 7

d. all of the above.

The CRT type monitor uses an electron gun to scan across a fluorescent screen, line by line, to produce a light image.
REF: p.94

Question 8

76. LCD stands for:

a. liquid cathode display.
b. liquid crystal display.
c. logarithmically created digitization.
d. layered components diagram.

Answer 8

b. liquid crystal display.

LCD stands for liquid crystal display and is a type of monitor.
REF: p.94

Question 9

77. Which of the following passes light through liquid crystals to display the image on the glass faceplate?

a. Cathode ray tube monitor
b. Liquid crystal display monitor
c. Plasma display panel monitor
d. Thin-film transistor monitor

b. Liquid crystal display monitor

LCD monitors pass light through liquid crystals to

Answer 9

b. Liquid crystal display monitor

LCD monitors pass light through liquid crystals to display the image on the glass faceplate.
REF: p.94

Question 10

78. The monitor matrix size should be __________ the image matrix size.

a. smaller than
b. at least as large as
c. five times larger than
d. ten times larger than

Answer 10

b. at least as large as

The monitor matrix size needs to be at least as large as the image matrix size. If it is smaller, there will be details that won’t be seen. Having the monitor matrix five or ten times larger is unnecessary and very expensive.
REF: p.96

Question 11

79. Diagnostic interpretation should be done at a high-resolution __________ display monitor.

a. 1 megapixel
b. 2 megapixel
c. 5 megapixel
d. 15 megapixel

Answer 11

c. 5 megapixel

Diagnostic interpretation should be done at a high-resolution 5-megapixel (2048 × 2560 pixels) display monitor.
REF: p.96

Question 12

80. The DICOM GSDF is used to evaluate the:

a. display monitor.
b. film processor.
c. histogram analysis.
d. digital imaging system.

Answer 12

a. display monitor.

The DICOM Grayscale Standard Display Function (GSDF) is used to evaluate the display monitor.
REF: p.96

Question 13

81. The distracting area of increased brightness surrounding a collimated image can be removed from the displayed digital image by:

a. masking.
b. shuttering.
c. electronic collimation.
d. all of the above.

Answer 13

d. all of the above.

Masking, shuttering, and electronic collimation are all terms that describe the ability to limit the area of an image to be viewed.
REF: p.98

Question 14

82. Decreasing the window level will result in an image with:

a. lower contrast.
b. higher contrast.
c. decreased brightness.
d. increased brightness.

Answer 14

c. decreased brightness.

A lower window level results in an image with decreased brightness.
REF: p.98

Question 15

83. Increasing the window width will result in an image with:

a. lower contrast.
b. higher contrast.
c. decreased brightness.
d. increased brightness.

Answer 15

a. lower contrast.

Increasing window width results in a digital image with lower contrast.
REF: p.99

Question 16

84. This post processing technique reduces the visibility of image noise.

a. Smoothing
b. Contrast enhancement
c. Edge enhancement
d. Subtraction

Answer 16

a. Smoothing

Smoothing reduces the visibility of image noise.
REF: p.102

Question 17

85. This post processing technique improves the visibility of small, high contrast structures.

a. Smoothing
b. Contrast enhancement
c. Edge enhancement
d. Subtraction

Answer 17

c. Edge enhancement

Edge enhancement makes structures more visible.
REF: p.102

Question 18

86. The communication standard for medical information is:

a. PACS.
b. HL7.
c. DICOM.
d. RIS.

Answer 18

b. HL7.

HL7 is the communication standard for medical information, while DICOM is the standard for images.
REF: p.105

Question 19

87. The computer system designed to distribute, store, and display digital images is:

a. PACS.
b. HL7.
c. DICOM.
d. RIS.

Answer 19

a. PACS.

PACS (picture archival and communication system) distributes, stores, and allows the display of digital images.
REF: p.104

Question 20

88. The communication standard for information sharing between PACS and imaging modalities is the:

a. JPG.
b. HL7.
c. DICOM.
d. RIS.

Answer 20

c. DICOM.

The Digital Imaging and Communications in Medicine (DICOM) is the communication standard for information sharing between PACS and imaging modalities.
REF: p.105

Question 21

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

Answer 21

True

Once the digital data is sent to the computer, there is no difference between CR and DR imaging.
REF: p.75

Question 22

2 T/F There is no light produced with CR when radiation interacts with the IP.

Answer 22

False

There is a small amount of light emission when x-rays first interact with the CR imaging plate phosphor. However, this is not part of image formation.
REF: p.75

Question 23

3 T/F The quality of the CR latent image will remain the same for up to 6 h after exposure.

Answer 23

False

Exposed CR IPs should be processed within 1 h after exposure to prevent latent image deterioration.
REF: p.76

Question 24

4 T/F Both CR and DR are electronic detectors that combine image capture and image readout.

Answer 24

False

Only DR combines image capture and readout. CR requires the image to go through a separate reader unit following image capture.
REF: p.81

Question 25

5 T/F The DR system does not require a separate reader unit.

Answer 25

True The DR system sends the digital signal directly to the computer. REF: p.81

Question 26

6 T/F With an FPD, electrical charges from each DEL are read out separately.

Answer 26

True With the flat-panel detector, each DEL has its own capacitor to store the electrical charge which will then be read out separately. REF: p.81

Question 27

7 T/F Exit radiation is converted to visible light with the direct conversion detector.

Answer 27

False Exit radiation is converted directly to an electrical signal with direct conversion detectors. Light is only involved with indirect conversion detectors. REF: p.81

Question 28

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

Answer 28

True As compared to film-screen, one of the key advantages to digital imaging is its wide dynamic range. REF: p.83

Question 29

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

Answer 29

False Digital imaging still requires sufficient exposure to produce a quality image. Too low of an exposure will result in an image with significant quantum noise. REF: p.84

Question 30

10 T/F An image with high SNR will have decreased detail visibility.

Answer 30

False An image with high SNR will have increased detail visibility due to the minimal amount of quantum noise. REF: p.86

Question 31

11 T/F Bit depth is determined by the matrix size.

Answer 31

False Bit depth is determined by the analog to digital converter (ADC). REF: p.71

Question 32

12 T/F The spatial resolution of flat-panel receptors is generally superior to that of CR.

Answer 32

True The spatial resolution of flat-panel receptors is generally superior to that of CR. REF: p.82

Question 33

13 T/F The DQE is higher for DR when compared to CR.

Answer 33

True The DQE is higher for DR when compared to CR. REF: p.85