Deck 18: Viewing the Digital Image

Question 1

What is the basic photometric unit?

A) Lumen
B) Candela
C) Lux
D) Nit

Answer 1

Lumen

Question 2

Almost all digital images in medical imaging are viewed and interpreted on a __________________.

A) view box
B) CRT device
C) digital display device
D) television monitor

Answer 2

digital display device

Question 3

The ambient light at a digital image workstation should be ______________.

A) daylight bright
B) slightly dimmed
C) near darkness
D) complete darkness

Answer 3

near darkness

Question 4

__________________ is corrected by the application of an offset voltage.

A) Spatial resolution
B) Line noise
C) Image lag
D) Misregistration

Question 5

Reregistering an image to correct for patient motion is done with ________________.

A) edge enhancement
B) offset images
C) pixel shift
D) image inversion

Question 6

A computation of the mean pixel value within a region-of-interest is performed for ____________________.

A) quantitative radiology
B) edge enhancement
C) image inversion
D) window and level adjustment

Question 7

Which is not a part of PACS?

A) Film storage
B) A display system
C) A network
D) Image acquisition

Question 8

A liquid crystal is a material in a ______________________ state.

A) solid
B) state between a liquid and a solid
C) liquid
D) state between a liquid and a gaseous

Question 9

Compared to CRTs, AMLCDs have __________________.

A) better contrast
B) better gray scale definition
C) less intrinsic noise
D) All of the above

Question 10

A digital display monitor is best viewed ______________.

A) straight on
B) from above
C) from below
D) at a 30° angle

Question 11

Medical flat panel display devices are identified by the ___________________.

A) aperture ratio
B) depth of the monitor
C) size of the pixels
D) number of pixels

Question 12

PACS stands for _______________________________________.

A) Processing, Applications, and Computer Storage
B) Processing, Archiving, and Computer Storage
C) Physician Applications and Communication Systems
D) Picture Archiving and Communication Systems

Question 13

The national standard for image transmission in teleradiology is the ____________ format.

A) RIS
B) DICOM
C) MB
D) PACS

Question 14

Post-processing includes all of the following except _________________.

A) image inversion
B) signal interpolation
C) annotation
D) pixel shift

Question 15

Almost all medical flat panel digital display devices are _______________.

A) color liquid crystal displays
B) monochrome liquid crystal displays
C) color CRTs
D) monochrome CRTs

Question 16

The science of ______________ is the study of the response of the human eye to light.

A) physiology
B) optometry
C) photometry
D) ophthalmology

Question 17

Within a PACS network the secretarial workstation and the viewing workstation would both be called ________________.

A) mainframes
B) remote devices
C) clients
D) DICOMs

Question 18

Flatfielding is accomplished through automatic calibration images called _____________ and _______________.

A) magnification, edge enhancement
B) offset images, gain images
C) image flip, image lag
D) image inversion, pixel shift

Question 19

Preprocessing the digital image is done _____________, and post-processing is done ______________.

A) automatically, manually
B) manually, manually
C) manually, automatically
D) automatically, automatically

Question 20

The decreasing luminous intensity with increasing distance from the source of light follows _____________________.

A) the law of gravity
B) Murphy's law
C) cosine law
D) the inverse square law

Question 21

Text data and email are generated at a _____________________________ workstation in PACS.

A) Radiology Information System (RIS)
B) DICOM
C) image acquisition
D) archive retrieval

Question 22

Image file size is determined by ________ size and gray scale.

A) RIS
B) DICOM
C) matrix
D) pixel

Question 23

A digital display device with higher megapixels has better spatial resolution.

Question 24

An advantage to viewing the AMLCD screen is that the image quality is equally good viewed from any angle.

Question 25

What is the file size of an image with a 1026 × 1026 matrix and a 2.5 byte gray scale depth?

A) 2,565 bits
B) 1,053 bits
C) 26 MB
D) 2.6 MB