CR-DR 3

Question 1

Digital radiography was introduced in

Answer 1

1981 by Fuji

Question 2

In screen-film radiography, the radiographic intensifying screen is a

Answer 2

scintillator

Question 3

In CR, the response to x-ray interaction is seen as

Answer 3

trapped electrons in a higher energy metastable state.

Question 4

what material emit some light promptly in the way that a scintillator does following x-ray exposure.

Answer 4

barium fluorohalide

Question 5

The atoms of barium fluorobromide have atomic numbers

Answer 5

56, 9, and 35,

Question 6

remember

Answer 6

When metastable electrons return to their ground state, visible light is emitted.

Question 7

principal source of noise

Answer 7

scattered radiation

Question 8

Four principal characteristics of any medical image:

Answer 8

SCAN
1.Spatial resolution
2.Contrast resolution
3.Noise
4.Artefacts

Question 9

determines the spatial resolution of the digitized image,

Answer 9

SAMPLING RATE

Question 10

determines the number of grey levels in the digitized image.

Answer 10

quantization level

Question 11

is usually a hard disc

Answer 11

image buffer

Question 12

This is the place where a completed image can be stored temporarily until it is transferred to a workstation for interpretation or to an archival computer.

Answer 12

image buffer

Question 13

are the process of analog-to-digital conversion (ADC).

Answer 13

*Sampling and quantization

Question 14

Components of the optical subsystem:

Answer 14

1.Laser
2.beam-shaping optics
3.light-collecting optics
4.optical filters
5.photodetector