Exam 1- Principles of Exposure

Question 1

2 branches of radiographic quality-

Answer 1

visibility & recognizability (sharpness) of detail

Question 2

visibility of detail-

Answer 2

receptor exposure, contrast, & noise/artifacts

Question 3

recognizability (sharpness) of detail-

Answer 3

spatial resolution & distortion (size & shape)

Question 4

mAs only affects ____ of the image-

Answer 4

visibility

Question 5

short scale contrast used to look at-

Answer 5

bony anatomy

Question 6

noise-

Answer 6

any undesirable info. that interferes w: subject of interest in radiographic img.

Question 7

artifact-

Answer 7

any extraneous obj./unwanted img. that obscures desired info. in radiograph

Question 8

magnification (size distortion)-

Answer 8

diff. b/w size of object in img. vs actual size of obj.

Question 9

shape distortion-

Answer 9

difference between shape of obj. in img. vs actual shape of obj.

Question 10

elongation-

Answer 10

when object appears longer in img. than it actually is

Question 11

foreshortening-

Answer 11

when object appears shorter in img. than it actually is

Question 12

mA (milliamperage)-

Answer 12

measurement of flow rate of electrons through x-ray tube

Question 13

time (s) (exposure time)-

Answer 13

amt. of time in seconds during exposure

Question 14

mAs-

Answer 14

total exposure

Question 15

kVp-

Answer 15

-energy level of electricity being forced across x-ray tube
-peak energy level

Question 16

focal spot-

Answer 16

refers to specific target area on target surface of x-ray tube

Question 17

AEC-

Answer 17

allows rad. to set kVp & the system determines when adequate exposure reached IR

Question 18

density control-

Answer 18

each increment setting represents a 25% change in intensity

Question 19

APR-

Answer 19

preset technical factors

Question 20

2 sides of x-ray tube-

Answer 20

anode & cathode

Question 21

4 things needed to produce x-ray-

Answer 21

1.) source of electrons
2.) focusing cup
3.) way to speed up electrons
4.) way to stop electrons abruptly

Question 22

most of energy striking anode results in-

Answer 22

heat (only 1% results in x-ray photons)

Question 23

SID-

Answer 23

distance of CR from focal spot to IR

Question 24

Primary Radiation/Beam-

Answer 24

the beam from the focal spot that goes to the object being imaged (patient)

Question 25

remnant beam-

Answer 25

sometimes called image forming radiation/exit radiation/beam; where it exits patient down to IR

Question 26

amount of x-ray that passes through the body-

Answer 26

5% or less

Question 27

amount of the beam that results in scatter-

Answer 27

15%

Question 28

amount of the beam that is absorbed-

Answer 28

80%

Question 29

attenuation-

Answer 29

partial absorption of x-ray beam as it passes through body

Question 30

inherent filtration-

Answer 30

built into x-ray tube

Question 31

3 parts of inherent filtration-

Answer 31

1.) glass envelope 2.) insulating oil 3.) exit window

Question 32

added filtration-

Answer 32

added by the tech.

Question 33

filtration purpose-

Answer 33

absorb low energy x-ray photons before they reach patient

Question 34

beam restriction aka-

Answer 34

collimation

Question 35

anode heel affect-

Answer 35

difference in beam intensity along longitudinal axis of x-ray tube

Question 36

central ray-

Answer 36

center of x-ray beam & direction in which it travels

Question 37

grids purpose-

Answer 37

absorbes scatter

Question 38

grids job-

Answer 38

keep scatter from reaching IR

Question 39

scatter produced-

Answer 39

inside the patient