Patient Care: Chapter 2

Front 1

Exposure time symbols

Back 1

T or s

Front 2

Time= (symbol)

Back 2

s

Front 3

Time is in

Back 3

Units of seconds or fractions of seconds

Front 4

Longer exposure time results in production of ___ x rays and ____ image

Back 4

more (quantity) ;darker

Front 5

Long exposure times may result in ___ ___

Back 5

Motion artifact

Front 6

What do automatic exposure devices (AEC) do?

Back 6

Terminate exposure

Front 7

A measure of current flow rate

Back 7

mA

Front 8

Number of electrons

Back 8

Quantity

Front 9

Since _ and _ work together to determine the total quantity of xrays, high ___ is used to shorten exposure time to decrease motion artifact.

Back 9

mA; s; mA

Front 10

___ x ___ = ___ or milliampere-seconds

Back 10

mA; s; mAs

Front 11

MA settings of 150 or less use ___ focal spot.

Back 11

Small

Front 12

Higher ___ settings also produce more heat.

Back 12

mA

Front 13

Tube can handle high heat doses more effectively with lower ___ and longer ___.

Back 13

mA; exposure time

Front 14

kVp -

Back 14

Kilovoltage peak

Front 15

kVp determines wavelength of radiation and thus its _____ _____.

Back 15

Penetrating power

Front 16

The greater the penetrating power, the more ___ ___reaches the film.

Back 16

remnant radiation

Front 17

What determines the quality of the beam?

Back 17

kVp

Front 18

An increase in ___ = darker image

Back 18

kVp

Front 19

___ is measured in inches or feet

Back 19

Distance

Front 20

The distance from the source (tube target) to the image (IR) is

Back 20

SID

Front 21

SID affects the ____ (# of photons per square inch) of the xray beam.

Back 21

Intensity

Front 22

Because of the divergence of the beam as ____ increases, _____ decreases.

Back 22

distance; intensity

Front 23

What is the inverse square law?

Back 23

Intensity of the radiation is inversely proportional to the square of the distance.

Front 24

Square inverse law formula

Back 24

Intensity= 1/d^2

Front 25

What are the common cassette sizes

Back 25

8×10, 10×12, 14×17

Front 26

Not so common cassette sizes

Back 26

14×34

Front 27

Intensifying screens do what to needed exposure?

Back 27

Reduce exposure needed by 50-100 times.

Front 28

Only 5% of film density is due to ___.

Back 28

Xrays

Front 29

Detail screens are only used for what exams?

Back 29

Tabletop work of extremities.

Front 30

Film is ___ or ___ light sensitive film.

Back 30

Green; blue

Front 31

Intensifying screen crystals must match the ____.

Back 31

Film

Front 32

Film can be processed in:

Back 32

• A darkroom with a traditional wet processor
• a "daylight" system
• a "dry" system

Front 33

Filmless radiography includes:

Back 33

• CR (computed radiography)
• DR (direct digital radiography)

Front 34

All images are managed in a system called:

Back 34

PACS (Picture Archiving and Communication System)

Front 35

Four elements of image quality are:

Back 35

• optical density
• image contrast
• image detail (definition or resolution)
• distortion

Front 36

Optical density-

Back 36

The overall blackness of the image due to the amount (quantity) of remnant radiation reaching the IR.

Front 37

Optical density is primarily controlled by

Back 37

mAs

Front 38

Contrast-

Back 38

A variation in density and determines the appearance (quality) of the image on the film.

Front 39

Contrast is primarily controlled by

Back 39

kVp

Front 40

Contrast and density are ___

Back 40

interdependent

Front 41

You can have ____ without ___, but you cannot have ___ without ___.

Back 41

Density, contrast, contrast, density

Front 42

If there is a big difference between shades of black and white, then contrast is ___ and there are few shades of grey resulting in less detail.

Back 42

High

Front 43

High contrast is also called

Back 43

Short scale or narrow latitude

Front 44

Decrease __to get higher contrast

Back 44

kVp

Front 45

If there is a small difference in adjacent shades of black and white, then contrast is __ and there are many shades of grey which can also result in less detail

Back 45

Low

Front 46

Low contrast is also called

Back 46

Long scale or wide latitude

Front 47

With low contrast image has an overall ___ appearance.

Back 47

Grey

Front 48

Increase ___ if low contrast is desired.

Back 48

kVp

Front 49

Image detail-

Back 49

The sharpness of the image

Front 50

___ ____ has sharp lines and edges.

Back 50

High definition

Front 51

___ ____ has less distinct lines and edges.

Back 51

Low definition

Front 52

Detail is affected by:(5)

Back 52

• Density
• contrast
• fog
• patient motion
• focal spot size

Front 53

Detail is a affected by:(2)

Back 53

• SID
• OID

Front 54

Detail __ as SID increases

Back 54

Increases

Front 55

Detail ___ as OID increases

Back 55

Decreases

Front 56

Distortion-

Back 56

The misrepresentation of the true size and shape of an object

Front 57

Size distortion in xrays is in the form of __.

Back 57

Magnification

Front 58

Shape distortion is unequal magnification is due to ___.

Back 58

Angulation

Front 59

Factors contributing to distortion/magnification:(3)

Back 59

• Beam alignment (angulation)
• OID (magnification increases as OID increases)
• SID (magnification decreases as SID increases)

Front 60

Magnification ___ as OID ___

Back 60

Increases; increases

Front 61

Magnification ____ as SID ____

Back 61

Decreases; increases