physics recording test 3

Question 1

What does DR stand for?

Answer 1

Direct Readout digital radiograph

Question 2

Computer radiography screens respond to radiation with the

Answer 2

photostimulable luminescence

Question 3

A photostimulable phosphor in a metastable state

Answer 3

immediately dies???

Question 4

Prompt emission

Answer 4

immediately

Question 5

Barium Fluoro Halide is coated with

Answer 5

Europium (activator)

Question 6

The computer radiography cassette is called?

Answer 6

Imaging Plate

Question 7

Photostimuable phosphor screen is handled in a :

Answer 7

Reader

Question 8

The computer radiographic reader is made of:

Answer 8

mechanical, optical (laser), & computer modules

Question 9

4 steps of creating an image

Answer 9

metastable state, stimulate, read & erase

Question 10

The digital image can sit for some time after the erase cycle

Answer 10

true, (not a good question)????

Question 11

The laser is one of the ….features of the computed radiography reader

Answer 11

optical

Question 12

optical filters are use to filter out the stimulating light & allow the ….light to reach the photodetector

Answer 12

emitted

Question 13

what is the green light?

Answer 13

emitted light and patient information

Question 14

The ouput signal from the PSP is converted from analog to digital by the

Answer 14

photodetectyor

Question 15

Computed Radiography & screen film imaging both have a

Answer 15

Latent image

Question 16

The principal source of noise in computed radiography

Answer 16

scatter radiation

Question 17

With computed radiograpphy the contrast is

Answer 17

constant regardless of exposure

Question 18

The computed radiography image has:

Answer 18

improved contrast resolution and wide exposure latitude

Question 19

when switching from screen-film imaging to computed radiography . what step is gone?

Answer 19

reloading the cassette

Question 20

the laser beam must be less than 100nm in diameter in order to maintain

Answer 20

high spatial resolution

Question 21

…is prevented flooding in the erased IP with bright light

Answer 21

ghosting

Question 22

computed radiography produces….gray levels

Answer 22

10,000

Question 23

switching from screen-film imaging to computed radiography can….. patient dose

Answer 23

reduce

Question 24

Conventional xray tubes & cassettes are used with …radiography systems

Answer 24

computed

Question 25

In digital fluroscopy each matrix pixel represents:

Answer 25

atomic number and mass density

Question 26

In DR the brightness of an image is determined by

Answer 26

pixel value

Question 27

Computed radiography uses a ….image detector

Answer 27

phosphor

Question 28

In DR spatial resolution is improved with increased

Answer 28

matrix size

Question 29

The dynamic range determines the degree of

Answer 29

contrast resolution, spatial resolution, and motion blur

Question 30

Spatial resolution is determined by the ratio of

Answer 30

field of view divided by matrix size

Question 31

Computed radiography uses….for latent image formation

Answer 31

PSP

Question 32

What modality is best for spatial resolution? #1

Answer 32

Mammography

Question 33

What is the purpose of a thin-film transistor in a flat panel detector?

Answer 33

allow the active readout of the charge stored in the capacitator

Question 34

Amorphous……releases electrons when struck by light photons and amorphous… ….releases electrons when struck by xrays

Answer 34

silicon, selenium

Question 35

Indirect flat panel detectors in DR results in……….exposure to the patient and ……resolution.

Answer 35

less, less

Question 36

The latent image can be stored for up to

Answer 36

24 hours

Question 37

Layers of the IP

Answer 37

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