Ch. 3

Question 1

Fog is created by

Answer 1

scatter

Question 2

___ effect is not dependent on atomic # of tissue

Answer 2

compton

Question 3

___ effect is dependent on energy of incoming photon

Answer 3

compton

Question 4

___ effect: complete absorption of the incoming photon

Answer 4

Photoelectric

Question 5

The ___ effect occurs when an incoming photon loses some but not all of its energy, then changes its direction.

Answer 5

Compton

Question 6

In __ the Compton effect is used.

Answer 6

RT

Question 7

In __ the photoelectric effect is used.

Answer 7

Diagnostic Radiography

Question 8

____ occurs when the primary x-ray beam loses some of its energy (number of photons) as it interacts with anatomic tissue.

Answer 8

attenuation

Question 9

3 possible things that happen during attenuation:

Answer 9

1. absorption
2. scatter
3. photon transmission (hits the image receptor)

Question 10

Probability of photoelectric effect is dependent on the ___ photon and ___.

Answer 10

energy of the incoming x-ray, tissue atomic #

Question 11

Fewer interactions occur at higher kVp, but of those that do occur, the # of ___ is more likely.

Answer 11

compton

Question 12

The following describe the ___ effect:

• X-ray ionizes atom
• Low energy secondary x-ray photon created

Answer 12

Photoelectric

Question 13

can occur within all x-ray energies and is dependent only on the energy of the incoming photon, not the atomic number of the tissue.

Answer 13

compton effect

Question 14

X-rays are attenuated exponentially and generally reduced by ~ 50% for each 4 to 5 cm (1.6” to 2”) of tissue thickness. - This is why ___ is changed in obese pts

Answer 14

kVp

Question 15

Tissues composed of a higher atomic number will ___ beam attenuation

Answer 15

increase

Question 16

Increasing the compactness of the atomic particles (or density) will ___ beam attenuation

Answer 16

increase

Question 17

Higher kVp increases the energy of the x-ray beam and will ___ beam attenuation.

Answer 17

decrease

Question 18

4 factors affecting beam attenuation:

Answer 18

1. tissue thickness
2. type of tissue
3. tissue density
4. x-ray beam quality

Question 19

Remnant or exit radiation is composed of ___ and ___ radiation.

Answer 19

transmitted, scattered

Question 20

Scatter radiation reaching the image receptor creates ___

Answer 20

Fog

Question 21

Air (low density) and fat (low atomic number) appear as ___ areas on the image

Answer 21

dark

Question 22

___ structures and structures with ___ atomic # appear light on the image

Answer 22

dense, high

Question 23

accuracy of structural lines (sharpness) is ___ and ___.

Answer 23

resolution/recorded detail, distortion

Question 24

Visibility of anatomic structures is ___ and ___.

Answer 24

density, contrast

Question 25

the range of densities visible on film is called ___.

Answer 25

scale of contrast

Question 26

number of different shades of gray that can be stored and displayed in a digital image is called ___

Answer 26

gray scale

Question 27

___ refers to the smallest object that can be detected in a digital image.

Answer 27

Spatial resolution

Question 28

___ refers to the distinctness or sharpness of the structural lines that make up the recorded film image.

Answer 28

Recorded detail

Question 29

Too few x-ray photons/not enough mA results in increased ___.

Answer 29

quantum noise

Question 30

Answer 30

motion unsharpness

Question 31

Answer 31

scatter/fog

Question 32

Answer 32

quantum noise

Question 33

Film-screen image receptors have a ___ dynamic range which ___ their ability to display tissues that vary greatly in x-ray attenuation.

Answer 33

limited, restricts

Question 34

If kVP/quality is increased:

beam attenutaion goes ___

absorbtion goes ___

transmission goes ___

Answer 34

down

down

up