fauber questions: chapter 4, 5, and 9

Question 1

which of the following would improve spatial resolution?

-large matrix
-large pixel size
-decreased pixel density
-increased pixel density

Answer 1

large matrix and increased pixel density

Question 2

the type of IR that uses a PSP to acquire a latent is ______________-

Answer 2

computed radiography

Question 3

what is used to extract the latent image from an imaging plate?

Answer 3

laser beam

Question 4

(increased/decreased) sampling frequency and (increased/decreased) sampling pitch will improve spatial resolution

Answer 4

increasing, decreasing

Question 5

what will improve spatial resolution of the digital image for a given FOV?

-large/small/fixed matrix size
-large/small IP

Answer 5

fixed matrix size and a small IP

Question 6

does a higher or lower bit depth give a greater range of shades of gray?

Answer 6

higher bit depth

Question 7

small anatomic detail has (high/low) spatial frequency

Answer 7

high spatial frequency

Question 8

___________ refers to the range of exposures that should be used to produce a diagnostic image

Answer 8

exposure latitude

Question 9

true/false: a lower SNR improves quality of an image

Answer 9

false

Question 10

true/false: decreasing the displayed FOV for a given matrix size will decrease the size of the pixels and increase spatial resolution

Answer 10

true

Question 11

what is a measurement of the efficiency of an IR in converting the x-ray exposure it receives to a quality radiographic image?

Answer 11

DQE

Question 12

a higher sampling frequency during CR latent image digitization will ____________

Answer 12

increase spatial resolution

Question 13

what will provide an indication of patient radiation risk during a radiographic procedure?

Answer 13

DAP and KAP

Question 14

image artifacts can be caused by…

-dirty CR plates
-low sampling frequency
-increased pixel density

Answer 14

dirty CR plates, low sampling frequency

Question 15

graphic representation of pixel values is a ___________

Answer 15

histogram

Question 16

what process is employed to maintain consistent digital image brightness for over or underexposure?

Answer 16

automatic rescaling

Question 17

which of the following is not a numerical value indicating the level of radiation exposure to the IR?

-sensitivity number
-exposure indicator
-window level
-exposure index

Answer 17

window level

Question 18

which of the following may impact the location and shape of the histogram?

-exposure technique
-positioning
-collimation

Answer 18

1, 2, and 3

Question 19

what digital process alters image brightness and grayscale to improve visibility of anatomic structures?

Answer 19

lookup tables (LUTs)

Question 20

true/false: maintaining a low level of ambient lighting can improve soft copy viewing of digital images

Answer 20

true

Question 21

display monitors used for soft-copy viewing of digital images should have __________

Answer 21

high luminance

Question 22

which of the following is not a function during post-processing of displayed digital images?

-histogram analysis
-electronic masking
-windowing
-edge enhancement

Answer 22

histogram analysis

Question 23

wider window width (increases/decreases) (brightness/contrast)

Answer 23

decreases contrast

Question 24

what postprocessing technique suppresses image noise?

Answer 24

smoothing

Question 25

what is the communication standard for information sharing between PACS and imaging modalities

Answer 25

DICOM

Question 26

true/false: the DI is a value that reflects the difference between desired or target exposure to the IR and actual exposure to the IR

Answer 26

true

Question 27

true/false: a DI of -0.75 reflects insufficient exposure to the IR

Answer 27

false

Question 28

DI values of 0.5 to -0.5 are _____________

Answer 28

within target range

Question 29

which of the following may occur as a result of the DI value greater than +3.0? -excessive noise visible -saturation -patient over exposure

Answer 29

2 and 3

Question 30

to transmit and store large amounts of imaging data, what may occur?

Answer 30

compression

Question 31

what is the latent image center for radiographic film?

Answer 31

sensitivity speck

Question 32

what describes a film's sensitivity to x-rays or light?

Answer 32

speed

Question 33

intensifying screens are used to _________

Answer 33

decrease patient exposure

Question 34

what automatic processing system primary maintains the chemical activity level?

Answer 34

replenishment

Question 35

what term is defined as a measure of the amount of light transmitted through the film?

Answer 35

optical density

Question 36

what is the diagnostic range of optical densities?

Answer 36

0.5 to 2.0

Question 37

a change of ____________ in OD results from a change in the percentage of light transmittance by a factor of 2

Answer 37

0.3

Question 38

changes in radiation exposure have the greatest effect on optical densities in which sensito-metric region?

Answer 38

straight line

Question 39

when the exposure technique used produces densities outside the sight-line portion of a senito0metric curve, how was contrast affected

Answer 39

decreased