Essentials of Digital Imaging Module 1, 2, 3, 4, 5, 6 and 7

1. The beam that contains useful or diagnostic information is known as the:

a. incident beam

b. remnant beam

c. penetrating beam

d. scattered beam

b. remnant beam

2. Digital imaging systems have a large dynamic range, which means that they can respond to a wide range of:

a. exposures

b. positions

c. body habitus

d. image receptors

a. exposures

3. In analog imaging, the intensifying screen converts x-ray into:

a. electrons

b. protons

c. a latent image

d. light photons

d. light photons

4. In an analog-to-digital converter, the analog input consists of:

a. numeric data

b. light photons

c. silver halide crystals

d. electrons

d. electrons

5. Which of the following symbols compose the binary language?

1. 0

2. 1

3. #

a. 1 and 2

b. 1 and 3

c. 2 and 3

d. 1, 2, and 3

a. 1 and 2

6. How many shades of gray does an 8-bit image display?

a. 8

b. 16

c. 64

d. 256

d. 256

7. As the pixel size decreases, the recorded detail:

a. increases

b. decreases

c. remains unchanged

d. is unknown

a. increases

8. Scintillation refers to a material's ability to give off:

a. electrons

b. heat

c. x-rays

d. light

d. light

9. The acronym PSP stands for photostimuable:

a. proton

b. phosphor

c. plate

d. platform

b. phosphor

10. During processing, image data is released from a PSP receptor after the receptor is struck by:

a. a red laser beam

b. x-radiation

c. an electron beam

d. a chemical beam

a. a red laser beam

11. Direct image formation converts x-rays into:

a. light photons

b. protons

c. numerical data

d. electrons

d. electrons

12. Individual components of a digital image are collected in areas of a thin-film transistor known as:

a. DELs

b. TFTs

c. PSPs

d. DQEs

a. DELs

13. Random information within a diagnostic image that detracts from the overall image appearance is known as:

a. contrast

b. detail

c. noise

d. density

c. noise

14. CCDs are suitable for low-dose imaging because they:

a. do not use a scintillator

b. respond to low light levels

c. use direct capture technology

d. refresh to a neutral state very slowly

b. respond to low light levels

15. DQE is a measure of image:

a. size

b. equivalence

c. density

d. quality

d. quality

16. Selecting a lower sampling frequency during image processing results in:

a. larger pixel size and lower spatial resolution

b. larger pixel size and higher resolution

c. smaller pixel size and higher resolution

d. smaller pixel size and lower spatial resolution

a. larger pixel size and lower spatial resolution

17. For flat-panel detectors, the spatial resolution is determined by the size of the:

a. image receptor

b. PSPs

c. DELs

d. imaging field

c. DELs

18. The Nyquist theorem states that for a given spatial resolution, you must sample the signal at _____ times the desired sampling frequency.

a. 2

b. 4

c. 8

d. 16

a. 2

19. A digital receptor can produce an image that appears acceptable on a display monitor, but that was produced between:

a. 100% underexposure and 100% overexposure

b. 50% underexposure and 100% overexposure

c. 50% underexposure and 50% overexposure

d. 100% underexposure and 50% overexposure

b. 50% underexposure and 100% overexposure

20. Which of the following is a visual cue that a digital image is underexposed?

a. loss of image contrast

b. loss of image resolution

c. increase in image size

d. increase in image noise

d. increase in image noise

21. Receptor blur is the result of:

a. image magnification

b. patient motion

c. image saturation

d. imaging equipment

d. imaging equipment

22. When a digital fluoroscopy unit's magnification button used, the resulting magnification is due to a decrease in the size of the:

a. input phosphor

b. output phosphor

c. photo cathode

d. focusing lenses

a. input phosphor

1. Scanning the bar code on a PSP plate is extremely important because it links the image data with the correct:

a. scanning parameters.

b. processing parameters.

c. field size.

d. patient.

d. patient.

2. Which device allows for an increased scanning precision compared with a mechanical arm?

a. rotating mirror

b. photocathode

c. detector element

d. entrance rollers

a. rotating mirror

3. In a PSP plate reader, the light guide collects the light and directs it into a:

a. photocathode.

b. photomultiplier tube.

c. thin-film transistor.

d. high-frequency sampler.

b. photomultiplier tube.

4. PSP plates are erased after processing by exposing the plate to:

a. high-intensity light.

b. a magnetic field.

c. high temperatures.

d. x-radiation.

a. high-intensity light.

5. When using a flat-panel detector, the technologist does not touch the:

a. patient.

b. x-ray tube.

c. collimator controls.

d. image detector.

d. image detector.

6. In a flat-panel imaging system, electrons are converted into digital values by a(n):

a. DEL.

b. TFT.

c. ADC.

d. DQE.

c. ADC.

7. What do both a charge-coupled device and a complementary metal oxide semiconductor need to change x-rays into light?

a. a scintillator

b. an analog-to-digital converter

c. a thin-film transistor

d. a histogram

a. a scintillator

8. What happens when a PSP plate reader is unable to identify the collimated borders of the image?

a. patient dose increases.

b. the reader rejects the image.

c. the image quality is poor.

d. the image is erased.

c. the image quality is poor.

9. A graphical representation of exposure values extracted from an image receptor is known as a:

a. matrix.

b. pixel.

c. histogram.

d. cinegraph.

c. histogram.

10. Type 3 a priori analysis is unique because it takes into account which patient characteristic?

a. age

b. body habitus

c. prosthesis

d. gender

c. prosthesis

11. Neural analysis compares exposure data from the receptor with:

a. maximum and minimum values.

b. values in a predefined data set.

c. values in a medium to maximum range.

d. patient-relevant values only.

b. values in a predefined data set.

12. Visual cues that an image has been overexposed are not easily seen in digital radiography because of:

a. rescaling.

b. histogram analysis

c. matrix size.

d. scintillators.

a. rescaling.

13. The acronym EI is a vendor-neutral term that stands for exposure:

a. index.

b. indicator.

c. increase.

d. improvement.

b. indicator.

14. All of the following are examples of EIs except:

a. "S" numbers

b. DQE

c. IgM

d. REX

b. DQE

15. The addition of a metal prosthesis into the image data set affects:

1. image brightness.

2. image contrast.

3. the EI.

a. 1 and 2.

b. 1 and 3.

c. 2 and 3.

d. 1, 2 and 3.

d. 1, 2 and 3.

16. If a PSP plate is processed using the wrong anatomical menu, what could happen?

a. the patient will be exposed to too much radiation.

b. the EI number might display improperly.

c. important anatomy could be removed from the image.

d. nothing; the image will look fine.

b. the EI number might display improperly.

17. Optimal EI ranges for each anatomical part should be set by the:

a. medical physicist.

b. radiographer.

c. manufacturer.

d. radiologist.

d. radiologist.

18. Which of the following is an EI used in flat-panel radiography?

a. EXI.

b. "S" number.

c. DQE

d. IgM

a. EXI.

19. A DAP meter measures patient dose as the x-rays:

a. enter the patient's skin.

b. exit the patient's skin.

c. interact with sensitive anatomy.

d. exit the x-ray tube.

a. enter the patient's skin.

20. All of the following are advantages to digitizing radiographs except:

a. it allows radiologists to view images in new ways.

b. it provides electronic access to digitized images.

c. the image can be uploaded to a PACS.

d. artifacts are removed during the process.

d. artifacts are removed during the process.

1. In CRT display technology, an electron gun fires electrons at a(n):

a. crystal.

b. photocathode.

c. fluorescent screen.

d. TFT display.

c. fluorescent screen.

2. An advantage of LCD monitors over CRT monitors is that LCD monitors:

a. are more durable.

b. lower measureable black levels.

c. have better color reproduction.

d. have less screen glare.

d. have less screen glare.

3. An LCD monitor's resolution is determined by:

a. bandwidth.

b. line spacing.

c. pixel pitch.

d. spot size.

c. pixel pitch.

4. Most LCD monitors have an aspect ratio of:

a. 1:1.

b. 4:3.

c. 16:9.

d. 12:1.

c. 16:9.

5. Which of the following increases as the matrix size of a display monitor increases?

a. pixel size

b. contrast resolution

c. spatial resolution

d. patient dose

c. spatial resolution

6. Pixel pitch describes:

a. how close pixels are to each other.

b. the size of the largest pixel.

c. the size of the smallest pixel.

d. how many pixels can be seen.

a. how close pixels are to each other.

7. To accurately display the gray scale in a radiograph, the display monitor must be able to demonstrate at least how many distinct shades of gray?

a. 8

b. 16

c. 64

d. 256

d. 256

8. The difference between the maximum and minimum luminance of a display system is called:

a. contrast resolution.

b. density difference.

c. spatial resolution.

d. temporal resolution.

a. contrast resolution.

9. Current ACR standards specify that gray-scale monitors used for interpreting radiographs provide a minimum of how many cd/m^2?

a. 120

b. 171

c. 256

d. 329

b. 171

10. How many images/second does it take CRT monitors to refresh?

a. 20 - 30

b. 30 - 60

c. 60 - 120

d. 120 - 200

c. 60 - 120

11. The delayed light emission that occurs in a CRT monitor after the screen refreshes is called:

a. luminance.

b. resolution.

c. persistence.

d. radiance.

c. persistence.

12. The brightness of a display monitor is referred to as:

a. luminance.

b. resolution.

c. persistence.

d. radiance.

a. luminance.

13. Modifying demographic and image data on a workstation also alters the:

a. exam parameters.

b. permanent patient record.

c. diagnostic information.

d. accession number.

b. permanent patient record.

14. If an image is acquired with the orientation of the image receptor upside down, what modality workstation tool can be used to orient the image the correct way?

a. rotate

b. crop

c. mask

d. annotate

a. rotate

15. Placing image information on an image after the examination is complete is called image:

a. marking.

b. annotation.

c. texting.

d. fraud.

b. annotation.

16. When an image is obtained on several imaging plates that need to be combined later into one image, the process is referred to as:

a. merging.

b. stitching.

c. combining.

d. annotating.

b. stitching.

17. Cassettes that are specially designed for scoliosis exams contain how many PSP plates?

a. 1

b. 2

c. 3

d. 4

b. 2

18. Using a workstation to cover the unexposed area of an image with a black border is called:

a. bordering.

b. shuttering.

c. collimating.

d. cropping.

b. shuttering.

19. Window and leveling on a workstation changes the digital image's:

a. brightness and contrast.

b. size and shape.

c. detail and sharpness.

d. orientation and angle.

a. brightness and contrast.

1. Which of the following would lead to decreased density on an analog (film-based) image?

a. increased kVp

b. extended processing time

c. a low developer temperature

d. increased base plus fog

c. a low developer temperature

2. Radiographic blur can be caused by:

1. patient motion.

2. incorrect grid ratio.

3. geometric factors.

a. 1 and 2

b. 1 and 3

c. 2 and 3

d. 1, 2 and 3

b. 1 and 3

3. Excessive radiation is defined as using more than _____ times the level of radiation needed to produce a diagnostic quality image.

a. 1.5

b. 3

c. 6

d. 7.5

b. 3

4. What error is caused by the computer's inability to identify the edges of collimation?

a. grid cutoff

b. exposure field recognition error

c. gross overexposure

d. gross underexposure

b. exposure field recognition error

5. Improper alignment of a radiographic grid during digital imaging can lead to improper:

a. magnification

b. rescaling

c. spatial resolution

d. contrast

d. contrast

6. Scatter radiation is especially difficult to interpret during histogram analysis when it occurs:

a. inside patient anatomy.

b. away from the image receptor.

c. outside of the collimated field.

d. within the x-ray tube.

c. outside of the collimated field.

7. Inappropriate brightness on a digital image can be caused by:

1. poor collimation.

2. incorrect menu selection.

3. poor positioning.

a. 1 and 2

b. 1 and 3

c. 2 and 3

d. 1, 2, and 3

d. 1, 2, and 3

8. When the exposure absorbed by the image receptor surpasses the level at which the image receptor can respond, what is said to occur?

a. saturation

b. capacity

c. fullness

d. permeation

a. saturation

9. What is the most common cause of image blur in digital imaging?

a. the patient

b. equipment

c. exposure settings

d. processing parameters

a. the patient

10. Shape distortion can be caused by:

a. subject-to-image receptor distance

b. object-to-image receptor distance

c. focal spot size and orientation

d. angular relationship of tube, part and image receptor

d. angular relationship of tube, part and image receptor

11. The primary cause of quantum noise is:

a. excessive scatter

b. excessive fog

c. insufficient signal strength

d. insufficient collimation

c. insufficient signal strength

12. DAP is a measurement of:

a. exposure

b. collimation

c. contrast

d. brightness

a. exposure

13. A lead apron in the exposure field may cause an exposure indicator miscalculation because the image data could be misrecognized as:

a. gross underexposure

b. gross overexposure

c. not having collimated edges

d. patient motion

a. gross underexposure

14. To reduce errors from collimation, the current recommendation is to:

a. avoid using collimation

b. repeat an image until the correct factors are achieved

c. record one image per image receptor

d. overlap exposure fields whenever possible

c. record one image per image receptor

15. Most digital artifacts appear:

a. black

b. white

c. gray

d. as a "void"

b. white

16. Most artifacts that appear when using cassette-based digital imaging are caused by:

a. dust and dirt.

b. entrance rollers.

c. rough handling.

d. patient factors.

a. dust and dirt.

17. Most artifacts that appear when using cassette-less systems are caused by:

a. entrance rollers.

b. DELs.

c. dust and dirt.

d. static electricity.

b. DELs.

18. Digital artifacts that are caused by processing:

a. appear along the entire axis of the image and on every imaging plate.

b. appear along the entire axis of the image and on select imaging plates.

c. don't cross the entire axis of the image or every imaging plate.

d. don't cross the entire axis of the image or select imaging plates.

a. appear along the entire axis of the image and on every imaging plate.

19. Artifacts caused by a dirty light guide appear:

a. white and irregular

b. black and linear

c. black and irregular

d. white and linear

d. white and linear

20. An artifact that presents as a wavy appearance in a localized area of an image is due to:

1. laser disruption.

2. plate disruption.

3. patient motion.

a. 1 and 2

b. 1 and 3

c. 2 and 3

d. 1, 2 and 3

a. 1 and 2

1. In the absence of a PACS, digital images can be:

a. laser printed.

b. stored on a network server.

c. viewed on the Internet.

d. sent wirelessly to an intranet.

a. laser printed.

2. How many people can view a digital image on a PACS simultaneously?

a. 2

b. 5

c. 7

d. more than 10

d. more than 10

3. The standard process for transmitting medical images and their associated information is known by the acronym:

a. SMPTE

b. DICOM

c. NEMA

d. LAN

b. DICOM

4. A modality workstation provides information that can be used by a limited number of users and is known as a:

a. DICOM

b. PACS

c. SCU

d. SCP

c. SCU

5. A radiology information system (RIS) can do which of the following?

a. collect and display orders

b. adjust image window and level

c. store electronic image data

d. prefetch prior image studies

a. collect and display orders

6. The software standards used for the exchange of text-based electronic information in health care are known as:

a. DICOM.

b. HIS.

c. HL7.

d. SCU.

c. HL7.

7. Workstations designated as "diagnostic workstations" typically are used only by:

a. radiographers.

b. medical physicists.

c. radiologists.

d. referring physicians.

c. radiologists.

8. Long-term storage of digital images occurs in which type of storage system?

a. workstation

b. online

c. archive

d. redundant array.

c. archive

9. A typical 5-view lumbar spine series requires storage space up to:

a. 5 MB.

b. 10 MB.

c. 20 MB.

d. 25 MB.

d. 25 MB.

10. Which of the following is an example of an image acquisition modality workstation?

a. CT scanner workstation

b. 3-D reconstruction workstation

c. quality control workstation

d. radiologist workstation

a. CT scanner workstation

11. A PACS uses a RAID as its main:

a. delivery device.

b. viewing device.

c. storage device.

d. acquisition device.

c. storage device.

12. Prefetching generally occurs at what time of day?

a. the start of the work day

b. during the lunch hour

c. near the end of the work day

d. during the night.

d. during the night.

13. The greatest benefit of installing PACS software on existing computers throughout the medical facility is increased:

a. image detail.

b. viewing functionality.

c. access.

d. image size.

c. access.

14. A typical PACS platform receives images from:

1. CT.

2. MR.

3. Digital fluoroscopy.

a. 1 and 2.

b. 1 and 3.

c. 2 and 3.

d. 1, 2 and 3.

d. 1, 2 and 3.

15. A computer network limited to a relatively small geographic area is known as a:

a. LAN.

b. WAN.

c. STAN.

d. GAN.

a. LAN.

16. Every computer on a network has a unique identifier known as a(n):

a. router address.

b. IP address.

c. operating address.

d. PACS address.

b. IP address.

17. What device connects 2 or more networks?

a. interface card

b. router

c. full network switch

d. half network switch

b. router

18. A firewall controls traffic between a single computer and a network in an environment with no:

a. connectivity.

b. storage.

c. security.

d. protocols.

c. security.

19. The major challenge with burning images to a disc to share the image information with another facility is:

a. size limitations.

b. high expense.

c. loss of use.

d. viewing images on the receiving end.

d. viewing images on the receiving end.