Chapter 10

Question 1

Fidelity of anatomical structures by the image.

Answer 1

Image quality

Question 2

What are the 4 factors that most affect image quality?

Answer 2

Spatial resolution
Contrast resolution
Noise
Artifacts

Question 3

Random variation in useful data or signal

Answer 3

Noise

Question 4

Example of audio noise

Answer 4

Static

Question 5

Random variation in optical density

Answer 5

Visual noise

Question 6

Which type of scatter is a primary determinant of noise?

Answer 6

Compton scatter

Question 7

Finite size of individual silver halide crystals on the film; will contribute to noise

Answer 7

Film grain

Question 8

Finite size of individual phosphor crystals of intensifiying screen will contribute to noise

Answer 8

Structure mottle

Question 9

Increased speed =

___ noise + ___ resolution

Answer 9

Increased noise

Decreased resolution

Question 10

Higher spatial and contrast resolution requires what?

Answer 10

Low noise and slower image receptors

Question 11

Higher speed =

____ patient dose

____ resolution and more noise

Answer 11

Decreased patient dose

Decreased resolution and more noise

Question 12

Slower speed =

___ resolution and image quality

___ patient dose

Answer 12

Better resolution and image quality

More patient dose

Question 13

For analog systems - A response curve for xray films that demonstrates density, contrast, speed, latitude

Answer 13

Characteristics curve
aka Hunter & Driffield Curve
aka H&D curve

Question 14

Range of exposures that will result in optical densities within useful range to human eye

Answer 14

Latitude

Question 15

More latitude (_____ slope) = ___ change in exposure on optical density scale and ___ change in contrast

Answer 15

Shallower slope

Less change in exposure

Less change in contrast

Question 16

Less latitude (___ slope) = ___ change in contrast

Answer 16

Steeper slope

Larger change in contrast

Question 17

What does SID stand for?

Answer 17

Source image distance

Question 18

What does SOD stand for?

Answer 18

Source object distance

Question 19

What does OID stand for?

Answer 19

Object image distance

Question 20

Uneven magnification

Answer 20

Distortion

Question 21

What are the contributing factors of distortion?

Answer 21

Object size, shape, position/orientation

Question 22

1/2 shadow

Answer 22

Penumbra

Question 23

Move the object closer to the source and further from the image receptor, the shadow looks ____

Answer 23

Bigger

Question 24

What does a decrease in KVp do to the contrast?

Answer 24

Increases contrast with shorter scale (less steps between dark and light)

Question 25

What does and increase in KvP do to contrast?

Answer 25

Decreases contrast image with longer scale (more steps between dark and light)