Distortion, Noise, Recorded Detail

Front 1

what is the best way to combat involuntary motion

Back 1

short exposure time

Front 2

the blur formula is expressed as: B=

Back 2

B=(FSSxOID)/SOD

Front 3

when the angle of the anode decreases (moves toward vertical) the actual focal spot size ?

Back 3

decreases

Front 4

why do image intensification screens inherently increase blur

Back 4

the size of the crystal and the light it emits is always much larger than the actual x ray photon

Front 5

when a film and screen combination has poor contact, this situation allows the light from the stimulate crystal to ? thus leading to an ? in blur

Back 5

diverge, increase

Front 6

when the angle of the anode increases (moves away from vertical) the effective focal spot size ?

Back 6

increases

Front 7

what relationship does anode heel effect and SID have

Back 7

inverse

Front 8

SOD stands for

Back 8

source to object distance

Front 9

increasing the crystal layer thickness in an intensifying screen increases blur, because, since the crystal is farther from the film, the light it emits continues to ? as it travels to the film

Back 9

diverge

Front 10

SID stands for

Back 10

source to image distance

Front 11

what relationship does anode heel effect and IR/ field size have

Back 11

direct

Front 12

what relationship does actual focal spot size and SID have

Back 12

no relationship

Front 13

because a fan shaped beam and because anatomical parts are not pyramid shaped, there are not definitive sharp edges, but fade from lighter to darker at the periphery of the anatomical part. This phenomenon is called ?

Back 13

edge gradient

Front 14

if a manufacturer increased the speed of an IR by increasing the layer thickness of the phosphor crystals, what effect does this have on recorded detail

Back 14

decrease

Front 15

what relationship does effective focal spot size and SID

Back 15

no relationship

Front 16

we do not always use a small FSS and a 72" SID because a small FSS equates to a ? mA station, and therefore, a ? time

Back 16

low, longer

Front 17

an increase in the size of the electron cloud due to the negative charges repelling each other is called

Back 17

blooming

Front 18

? is the opposite of recorded detail

Back 18

blur

Front 19

in order to cover a 17" FOV at 40" the angle of the anode must be ? degrees

Back 19

12

Front 20

if we use a right triangle as an illustration of the line focus principle, the base of the triangle represents the ?

Back 20

effective focal spot size

Front 21

what is the primary metal used in contrasting a focusing cup

Back 21

molybdenum

Front 22

which is typically always smaller, actual or effective FSS

Back 22

effective

Front 23

what relationship does effective focal spot size and anode heel effect have

Back 23

inverse

Front 24

list three ways of increasing IR speed

Back 24

increase crystal size, increase crystal compactness, increase crystal layer thickness

Front 25

? minus ? = SOD

Back 25

SID , OID

Front 26

of the two types of size distortion, which cannot occur in conventional film radiography

Back 26

minification

Front 27

percent magnification can be mathematically expressed as:

Back 27

SID-SOD/SOD x 100

Front 28

another name for blur is

Back 28

pnembra

Front 29

if we use a right triangle as an illustration of the line focus principle, the height of the triangle represents ?

Back 29

width of the electron beam

Front 30

the concept of considering the actual focal spot size and the projected effective focal spot size is called the ?

Back 30

line focus principle

Front 31

what type of shape distortion can occur as the result to angling the tube

Back 31

elongation

Front 32

? is the ability of the imaging equipment/system to record detail

Back 32

resolution

Front 33

anything that increases the effective focal spot size also increases the ?

Back 33

actual focal spot

Front 34

anything that increases the actual focal spot size also increases the ?

Back 34

effective focal spot

Front 35

noise degrades contrast and obscurs

Back 35

detail

Front 36

name the two types of distortion

Back 36

shape size

Front 37

when we go from a small FSS to a large FSS, what are actually changing

Back 37

filament size

Front 38

when it comes to recorded detail, a lower mA and longer time increases the risk of ?

Back 38

motion

Front 39

list three things that can combat voluntary motion

Back 39

clear communication, suspend respiration, immobilization

Front 40

because the light emitted from the crystals in an intensifying screen ? there is overlap of light from one crystal and its neighbor

Back 40

diverges

Front 41

if we use a right triangle as an illustration of the line focus principle, they hypotenuse of the triangle represents the ?

Back 41

acute focal spot size

Front 42

which type of shape distortion can occur as the result to angling the IR

Back 42

elongation

Front 43

if we use a right triangle as an illustration of the line focus principle, the base of the triangle represents the ?

Back 43

effective focal spot size

Front 44

MF can be mathematically expressed as ? divided by ? or as ? divided by ?

Back 44

SID/ SOD, image width/ object width

Front 45

How does the focusing cup work

Back 45

it has a greater negative charge than the combined negative charge of the electron cloud. forcing the electrons together

Front 46

the physical area on the anode that is bombarded by the electron beam is call the >

Back 46

cathode

Front 47

the noise, or graininess, seen on a radiograph taken using image intensifying screens, and it caused by an uneven distribution of photons across the image, is called ?

Back 47

quantum mottle

Front 48

the arch enemy of detail is

Back 48

motion

Front 49

name the two types of size distortion

Back 49

magnification, minification

Front 50

the size of the x ray beam at its origin, prior to divergence, that is projected downward toward the patient is called the ?

Back 50

effective focal spot

Front 51

a device called a ? is used in the radiographic tube to help control the expansion of the electron cloud

Back 51

focusing cup

Front 52

there are two types of motion ? and ?

Back 52

voluntary and involuntary

Front 53

? is the ability to use density/contrast to record information on the image; its how well and true the imaging system records anatomic structures

Back 53

recorded detail

Front 54

the misrepresentation of the true size and or sale of the object is ?

Back 54

distortion

Front 55

of all the noises that can occur on a radiographic image, which is the only one that is actually a lack of density

Back 55

quantum mottle

Front 56

we don't not always use a small FSS and 72" SID because a longer SID equates to a ? mAs and therefore often times a ? time

Back 56

hight, longer

Front 57

? is the ability of the viewer to see recorded detail

Back 57

visibility of detail

Front 58

for a given SID as the angle of the anode decreases (moves toward vertical), what happens to the actual field of view possible

Back 58

decreases

Front 59

due to the anode heel effect, which side of the beam has the greatest intensity

Back 59

cathode

Front 60

quantum mottle + structural mottle =

Back 60

screen mottle

Front 61

which type of shape distortion can occur as the result of misaligning the part in the relationship to the beam being perpendicular to the IR

Back 61

foreshortening

Front 62

the factors that influence recorded detail are all ? in nature

Back 62

geometric

Front 63

what relationship does actual focal spot size and IR/ field size have

Back 63

no relationship

Front 64

as crystal size increases blue increases, due the ratio of the size of the incident x ray photon and the size of the light emitted from the stimulated crystal ?

Back 64

no relationship

Front 65

as IR size increases the opportunity for poor film screen contrast ?

Back 65

increases

Front 66

another name for recorded detail is ?

Back 66

sharpness

Front 67

name the two types of shape distortion

Back 67

foreshortening, elongation

Front 68

if a manufacturer increased the speed of an IR by increasing the size of the phosphor crystals, what effect does this have on recorded detail

Back 68

decrease

Front 69

when the angle of the anode decreases (moves toward vertical) the effective focal spot size ?

Back 69

decreases

Front 70

what is the phenomenon that explains magnification

Back 70

the continued divergence of the beam

Front 71

what is the name of the blurring phenomenon that can only occur as the result of using a double emulsion film

Back 71

film base crossover

Front 72

which type of shape distortion can occur as the result of decentering the tube to the IR

Back 72

elongation

Front 73

the fact that x rays produced on the anode cannot penetrate the anode and exit the tube is called ?

Back 73

anode heel effect

Front 74

what relationship does effective focal spot size and SID have

Back 74

no relationship

Front 75

what relationship does effective focal spot size and IR / field size have

Back 75

no relationship

Front 76

what relationship does actual focal spot size and anode heel effect have

Back 76

inverse

Front 77

is it possible to have both size and shape distortion on the same image

Back 77

yes

Front 78

when the angle of the anode increases )moves away from vertical_ the actual focal spot size ?

Back 78

increases

Front 79

for a given SID as the angle of the anode increases, what happens to the actual FOV possible

Back 79

increases