Intro Chapter 7

Front 1

The study of energy and matter and how they relate:

Back 1

physis

Front 2

Energy is:

Back 2

the ability to do work

Front 3

Energy transmitted by waves thru space or thru a medium (matter/patient) is:

Back 3

radiation

Front 4

_________are radioactive b/c or the potassium.

Back 4

Bananas

Front 5

Any process by which a neutral atom gains or loses an electron, thus acquiring a net charge, becoming an ion is called:

Back 5

ionization

Front 6

What process damages DNA, disrupts life processes and is bad for your body?

Back 6

ionization

Front 7

Mechanical energy transmitted thru matter, return soundwaves are created is called?

Back 7

sound

Front 8

Which waves are non-ionizing but still has radiation?

Back 8

sound

Front 9

2 ionizing modalities:

Back 9

mammography and CT

Front 10

non-ionizing modality

Back 10

MRI

Front 11

Images of body's naturally emitted heat energy (charges in body's circulation) is called:

Back 11

thermograms

Front 12

A form of electromagnetic energy with the ability to ionize atoms
(natural reoccuring, comes from space) is called:

Back 12

Gamma radiation

Front 13

Radioactive substance that emits gamma radiation introduced into our body, (ionizing) is:

Back 13

Nuclear Medicine

Front 14

Radiation travels in ______ and ________ waves.

Back 14

short, long

Front 15

What is the making of records, known as radiography, of internal structures of the body by passage of x-rays or gamma rays through the body to act on specially sensitized film or imaging plate or system:

Back 15

Radiography
**man-made**

Front 16

What quantum or particle of radiant energy is created with the x-ray tube?

Back 16

photons

Front 17

Photons entering the body will either _______, be ________ or produce________ radiation.

Back 17

penetrate
absorbed
scattered

Front 18

Within the x-ray image, when bones are absorbed they appear__________.
When tissue is present, the image appears_______.

Back 18

white
black (b/c the light just goes thru)

Front 19

3 major classifications of diagnostic radiographic imaging:

Back 19

1. film & screen
**screens actually decreases the patient dose
2. fluoroscopic imaging
**"real-time" dynamic images
3. Digital or computerized imaging
**DR - direct & CR - cassette

Front 20

4 ingredients for x-ray:

Back 20

1. vacuum (tube housing)
2. source of electrons (filament)
3.method to accelerate electrons fast! (voltage)
4. method to stop electrons (target)

Front 21

What substance is in the casing of the tube to help disapate the heat?

Back 21

oil

Front 22

The casing or housing of the tube is made out of:

Back 22

lead.
however, some radiation still gets out

Front 23

The x-ray tube produces how much heat?

Back 23

99%

Front 24

The x-ray tube produces how much radiation?

Back 24

1%

Front 25

What produces as it goes through the body and then goes somewhere else? It's not useful information and bad for the x-ray.

Back 25

scatter radiation

Front 26

What are some examples that contribute to more scatter?

Back 26

higher KV & wider collimination

Front 27

What can be used to help reduce or catch scatter?

Back 27

a grid

Front 28

A beam of x-ray, mechanically produced by passing high voltage through a ________ ray tube.

Back 28

cathode

Front 29

The interpretation device is called________ that intercepts the x-ray photons that are able to exit the patients.

Back 29

image receptor (IR)

Front 30

The path of a beam of x-radiation.
1. The PRIMARY beam exits the x-ray tube. 2. The beam enters the patient, where the photons are altered (attenuated) by their passage thru body tissue. 3. The attenuated, or remnant (left overs), beam exits the patients carrying w/it an energy representation of the body tissues traversed.

Back 30

cont... 4. the x-ray photons in the remnant beam strike the phosphor crystals of the intensifiying screens, causing them to emit many light photons for each incident x-ray photon. 5. The light photons photographically expose the film emulsion, resulting in an invisible "latent" image.

Front 31

A process by which a beam of radiation is reduced in energy when passing through tissue or other materials.

Back 31

attenuation (altered)

Front 32

Not easily penetrabel by x-rays or other forms of radiant energy
exp: bones, photons can't get thru

Back 32

radiopaque

Front 33

Permitting the passage of x-rays or other forms of energy with little attenuation
exp: tissue/air, photons slide on thru

Back 33

radiolucent

Front 34

quantum or particl of radiant energy
"little balls of energy"

Back 34

photon

Front 35

example of single emulsion

Back 35

mammo

Front 36

example of double emulsion

Back 36

x-ray film

Front 37

The Imaging Chain:
1st - Remnant Beam (left overs after the radiation exits the patient)
2nd - IR (film/screen)

Back 37

****

Front 38

The image is stored in the emulsion until it is processed. The invisible image is called:

Back 38

latent image
(crystals holding on to the picture)

Front 39

Onc the film has been processed, the visual image appears, this is called:

Back 39

manifest image
(what you can actually see)

Front 40

glows/emits light:

Back 40

luminesce

Front 41

2 tpyes of luminesce:

Back 41

1. fluoroscene. (glow while being stimulated)
2. phosphorescence. (screenlag or afterglow - continues to glow)

Front 42

Thin layers of cardboard or polyester coated w/layers of luminescent phosphor crystals.

Back 42

Intensifying screens

Front 43

Modern radiographic film has an emulsion coating on both sides and is known as:

Back 43

duplitized or double-emulsion film.
**duplitized film is designed to be used w/two intensifying screens for the most efficient performance.

Front 44

What type of crystals are painted on the film?

Back 44

silver halide

Front 45

Silver halide crystals are made of:

Back 45

90% silver bromide
10% iodide

Front 46

Film - 2 main components:

Back 46

1. base = polyester
2. Emulsion = silver halide suspended in gelatin (gelatin is clear to allow light thru)

Front 47

Film processing: the film must be...

Back 47

developed, fixed, washed & dried

Front 48

What process has allowed the film processing to be compressed into 90 seconds?

Back 48

automatic processing

Front 49

"wet reading"

Back 49

film still wet

Front 50

______ is energy transmitted by waved thru space or a medium.

Back 50

radiation

Front 51

______is any process by which a neutral atom gains or loses an electron, thus acquiring a net charge.

Back 51

ionization

Front 52

______is an example of a nonionizing form of radiation used in an imaging study.

Back 52

ultrasound (soundwaves)

Front 53

Gamma rays originate from:

Back 53

the nucleus of radioactive substances

Front 54

What is a photon?

Back 54

a little ball of energy

Front 55

When an x-ray photon enters the body, on of 3 things will happen. What are those 3 things.

Back 55

1. scatter
2. pass thru the body
3. stop

Front 56

The x-ray tube produces more than 99%_______, when creating an image.

Back 56

heat/light

Front 57

The ________ houses the 2 small filaments inthe x-ray tube.

Back 57

focusing cup

Front 58

The anode is made of:

Back 58

tungsten

Front 59

______ is defined as "not easily penetrated by x-rays or other forms of radiant energy.

Back 59

radiopaque

Front 60

A technologist must select and control _______and _______.

Back 60

*quality (penetration/POUCH)
*quantity (how many photons are going thru)

Front 61

mA =
S =
***mA x s = mAs

Back 61

mA = milliamperage
S = time in seconds

Front 62

mAs controls:
"MAD tv"

Back 62

the quantity of x-ray photons produced during an exposure (speed) and the "radiographic density"

Front 63

The degree of darkening of exposed and processed photographic or radiographic film, sometimes used to discuss the brightness of the image.

Back 63

Density

Front 64

If you increase density, "higher density", what happens to the image?

Back 64

gets darker

Front 65

If you decrease denstiy, what happens to the image?

Back 65

gets lighter

Front 66

Any combination of mA and time producing equivalent mAs values should produce equivalent exposures and therefore densities. The process is called?

Back 66

mAs reciprocity

Front 67

kV =
p =
kVp =
"KC and the sunshine band"

Back 67

kV = kilovoltage
p = peak
kVp = Contrast - punch!, the penetration, quality (but some quantity)
***the ability of the x-ray beam to pass thru an object

Front 68

SID stands for:
and means what?

Back 68

source-to-image receptor distance
*the distance b/w the point of x-ray emission (anode) in the x-ray tube (focal spot) and the image receptor (IR).
*also effects the geometic properties of the image (magnification).
exp. as SID (distance) increase, beam intensity decreases

Front 69

SOD stands for:

Back 69

anode (tube)- to- object being radiographed
(b/t tube & park)

Front 70

OID stands for:

Back 70

object-to-image recepter (IR)
distance

Front 71

**A radiograph must exhibit proper quality to be deemed diagnostic and should demonstrate all of the desired info w/in the range of acceptance.***

Back 71

***

Front 72

Radiographic quality factors (or acceptance characteristics of a radiograph) are:

Back 72

1. photographic qualities
2. geometric qualities

Front 73

Photographic qualities include:

Back 73

*density (overall blackening of the film)
*contrast (the visible difference b/w adjacent densities)

Front 74

Geometric qualities include:

Back 74

*recorded detail (distinct representation of an objects true borders, or edge
*distortion (misrepresentation of the true size or shape of the object of interest

Front 75

Note: exception on the term "density".
A Radiologist may use the term "density" as anatomic and not radiographic!

Back 75

***

Front 76

15% Rule:
Increase kVp 15%, will ____ image receptor exposure.

Back 76

double
**doubles the darkness that the IR gets

Front 77

Decrease kVp 15%, will ____
image receptor exposure.

Back 77

halve

Front 78

polyenergetic or heterogeneous

Back 78

*high or low wave lengths
*many energies in the beam

Front 79

To change kVp (contrast) while maintaining the same IR exposure:
*Increase kVp 15%, _____ mAs
*Decrease kVp 15%, _____
mAs

Back 79

*half (b/c the IR darkening has doubled)
*double

Front 80

With distance,
*as distance decreases, the intensity______.
*as distance increase, the intensity_____.

Back 80

*increases
*decreases

Front 81

Inverse Square Proportion Law:

Back 81

The intensity of radiation at a given distance is inversely proportional to the square of the distance b/t the object and the source.
"Distance changes"

Front 82

The Inverse Square Law equation:

Back 82

original intensity (I1) / new intensity (I2) = new distance (d2)^2 / original distance (d1)^2

Front 83

Direct Square Law b/c of:
(exposure/density maintenance)

Back 83

*the Inverse Square Law
*technical factors must be adjusted to compensate for changes in distance
*this will "maintain" radiographic density

Front 84

**You must ______ mAs to compensate for the added distance

Back 84

increase

Front 85

Direct Square Law equation:

Back 85

original mAs 1 / new mAs 2 = original distance (D1)^2 / new distance (D2)^2

Front 86

_______ is a math formula that describes the relationship b/t radiation intensity and distance from the source of the radiation.

Back 86

Inverse Square Law

Front 87

_______ is defined as "not easily penetrable by x-rays or other forms of radiant energy.

Back 87

radiopaque

Front 88

Luminesce is defined as ____.

Back 88

glowing

Front 89

More than ______% of the photographic effect on a film/screen radiograph is due to screen light, and the remaining effect due to the direct action of x-ray photons.

Back 89

99%

Front 90

Modern radiographic film has an emulsion coating on both sides known as______.

Back 90

silver halide

Front 91

The "15% rule" helps explain the effect of _______ on exposure.

Back 91

kVp

Front 92

The chief controlling factor of radiographic density is _______.

Back 92

mAs

Front 93

______is the overall darkening of a film in response to light or x-ray photons.

Back 93

density

Front 94

mAs controls the number of electrons that flow from the ______ to the ______ in the x-ray tube.

Back 94

filament
anode or target

Front 95

"Any combination of mA and time producing equivalent mAs valves should produce equivalent exposures and therefore densities" is known as_______.

Back 95

reciprocity

Front 96

*high kVp = ______ scale (low contrast)
*low kVp = _______ scale (high contrast)

Back 96

*low (exp. chest)
*high (exp. hand)

Front 97

The x-ray beam can be modified before & after it enters the patient.
*Before: primary beam modification (coming out b/f it enters the patient) 2 types
*After:

Back 97

*Before:
1. filtration (used to attenuate material, usually aluminum b/t tube & pt to remove low energy photons, exp. lamp shade)
2. beam limitation
After:
scatter control process

Front 98

mAs controls ______ = ______

Back 98

density (overall darkening)
quantity

Front 99

Half value layer:
the amt. of absorbing materials that will reduce the intensity of the x-ray beam to 1/2 its original value.

**used as a way to express x-ray beam quality

Back 99

mm Al/Eq (millimeters of aluminum)

mm= millimeters
Al = aluminum
Eq = equivalency

Front 100

Scatter Control:
*Interaction of x-ray w/any matter produces scatter radiation
*scatter radiation provides little diagnostic information to the image
*detracts from image quality w/the creation to "fog" - unwanted radiographic densities
*common methods of scatter control
*kV causes more scatter

Back 100

**

Front 101

Ways to control scatter:

Back 101

*reduce collimation
*lead shields
*PBL (positive beam limitation - automatic collimates)
*Grid

Front 102

Grid:

Back 102

*used to reduce the amt. of scatter
*intercepts a portion of the remnant radiation
*improve image quality
*are described according to grid ratio & frequency
*it is neccessary to increase exposure to compensate for the grid

Front 103

Grid ratio:

Back 103

*ratio of the height of lead strips to the distance b/w them.
***5:1 to 16:1 are common ratios
***10:1 grid produces an image w/less exposure or film density.

Front 104

________ is a numerical representation of the "quantity of light photons" given off per x-ray photon interaction.

Back 104

"screen speed"
*numbers have specific valve when comparing one screen w/another.

Front 105

System speed ratings are based on an arbitrary average "relative speed" of ____.
*range from 50 - 1200

Back 105

100
exp. the higher the relative speed number, the less radiation required to produce a given exposure or film density. However, the higher-speed film/screen combo also produce an image w/ less recorded details.
(800-1600 film speed)

Front 106

"screen speed" example:
a screen w/a relative speed of 100 will give off 100 light photons p/x-ray photon. This will "intensify" the remnant beam 100x.
A "200" speed screen would give off 200 light photons p/x-ray (2x the light as the 100 speed)
*need 1/2 as many x-rays for the same density

Back 106

***

Front 107

Processing:
inaccurate processing is responsible for destroying many carefully exposed radiographs.
2 errors:

Back 107

1. chemials
*concentration & contamination
2. temperature
*too high or too low, a difference of only .5 degrees can produce a visible change in film density

Front 108

kVp is the chief controlling factor of:

"KC & the sunshine band"

Back 108

contrast!!!
*how much is getting thru. the visible difference b/t adjacent radiographic densities.

Front 109

Influencing factors that affect contrast:

Back 109

*patients (body habitus),
*mAs,
*pathology,
*beam modification (anything that decreases scatter increases contrast),
*film/screen combination (the faster the system - 100 speed, etc., the higher the contrast),
contrast media (for areas w/low subject contrast, contrast media attenuates more beam than the targeted tissue),
processing (underdevelopment or overdevelopment affects density which in turn degrades the radiographic contrast)

Front 110

anything that decreases scatter increases contrast

Back 110

beam modification

Front 111

the faster the system - 100 speed, etc., the higher the contrast

Back 111

film/screen combination

Front 112

for areas w/low subject contrast, contrast media attenuates more beam than the targeted tissue

Back 112

contrast media

Front 113

underdevelopment or overdevelopment affects density which in turn degrades the radiographic contrast

Back 113

processing

Front 114

Geometric qualities affect:

Back 114

"sharpness" or resolution and distortion

Front 115

what affects sharpness?

Back 115

motion, object unsharpness, focal spot size, SID, OID (object-to-image) and material unsharpness

Front 116

movement of the patient or part resulting in blur is called:

Back 116

motion
*voluntary
*involuntary

Front 117

objects don't have straight edges or angles, this is called:

Back 117

object unsharpness

Front 118

The sharpness with which an object's borders and structural details are represented on an image is referred to as:

Back 118

recorded detail or sharpness of detail, definition and resolution

Front 119

The specific area on the anode surface where x-ray originates from

Back 119

focal spot

Front 120

small or large focal spot results in "sharper image" due to less beam width?

Back 120

small

Front 121

small or large focal spot results in more blur due to wider beam width

Back 121

large

Front 122

longer or shorter SID results in sharper images due to less magnification of the image

Back 122

longer (exp. 72")

Front 123

longer or shorter SID results in more image blur due to more magnification

Back 123

shorter (exp. 40")

Front 124

image sharpness (a high degree of recorded detail) means:

Back 124

umbra

Front 125

image blur (low degree of recorded detail) means:

Back 125

penumbra

Front 126

as SID inc., penumbra....

Back 126

decreases (less blur)

Front 127

as SID dec., penumbra...

Back 127

increases (more blur)

Front 128

OID (object to image)
*smaller or longer OID = better detail?

Back 128

smaller

Front 129

as OID inc., penumbra...

Back 129

increases (more blur)

Front 130

as OID dec., penumbra...

Back 130

decreases (less blur)

Front 131

Films and screens have characteristics that affect the ability to represent an image accurately.

Back 131

***

Front 132

with a faster system =

Back 132

loss of detail but less patient radiation dose

Front 133

with slower system =

Back 133

higher detail but increase patient's radiation dose

Front 134

The process by which a beam of x-ray photons is altered as it passes through matter is known as?

Back 134

attenuation

Front 135

The beam of radiation as it exits the x-ray tube and before it reaches the patient is?

Back 135

primary radiation

Front 136

The chief controlling factor of radiographic contrast is?

Back 136

kilovoltage peak (kVp)

Front 137

Which of the following is not a radiographic contrast medium?
a. barium compounds
b. air
c. iodine compounds
d. water

Back 137

d. water

Front 138

The most common cause of radiographic unsharpness is:

Back 138

motion

Front 139

Which of the following uses x-radiation to produce a digital computer image?
a. ultrasound
b. nuclear medicine
c. CT
d. MRI

Back 139

c. CT

Front 140

The 15% rule helps explain the effect of _____ on exposure.

Back 140

kVp (kilovoltage peak)

Front 141

"being able to see on object from another in an image" is:

Back 141

contrast

Front 142

Can you increase mAs to compensate for inadequate penetration/contrast in an image?

Back 142

no, mAs has no effect on penetration of the beams ability

Front 143

If I increase my kVp, my contrast ______, with a ______ scale of gray.

Back 143

decrease,
long

Front 144

film speed:

Back 144

*incr. film speed (exp 800) = less radiation, but less detail
*slower film speed (exp 100) = more radiation, but better quality

Front 145

define contrast:

Back 145

the visible difference b/t adjacent structures on a radiographic image

Front 146

*photographic factors:
*geometic qualities:

Back 146

*density & contrast
*detail & distortion

Front 147

The _______ is an electronic interlock system that automatically collimates the beam to the size of an image.

Back 147

PBL - Positive Beam Limitation

Front 148

Grids improve contrast?

Back 148

yes

Front 149

The interspace in grids is usually made of _______ b/c it does a good job of absorbing low energy photons.

Back 149

aluminum

Front 150

Define: Grid Ratio

Back 150

the ratio of the height of lead strips to the distance b/w them

Front 151

Increasing the screen speed will do what with the patient exposure?

Back 151

reduce/decrease

Front 152

Increasing the kVp does what to the contrast in an image?

Back 152

reduce/decrease

Front 153

_______ is the fuzzy border of an object as imaged radiographically.

Back 153

penumbra

Front 154

What is the misrepresentation of the true size or shape of an object on a radiograph?

Back 154

distortion

Front 155

2 types of distortion:

Back 155

1. size
2. shape

Front 156

size distortion does what to an image?

Back 156

magnifies
*reason for "standard SID's"

Front 157

magnification decreases as OID _______.

Back 157

decreases
*try to get the smallest OID

Front 158

if SID increases = ______ magnification

Back 158

decreases

Front 159

if SID decreases = _______
magification

Back 159

increases

Front 160

if OID increases = _______ magnification

Back 160

increases

Front 161

if OID decreases = ________
magnification

Back 161

decreases

Front 162

shape distortion does what to an image?

Back 162

e"long"ation or fore"short"ening
**central ray angle or rotation of the body part will affect shape
**can control both to some extent***

Front 163

Ideally, the goal of a RT is to the place anotomic part ______ to the IR and have the CR aligned _________ to the IR.

Back 163

parallel, perpendicular

Front 164

What makes a "good" film?

Back 164

balance b/t photographic and geometric properties

Front 165

*use of x-ray to create "real-time" images
*requires radiographic/fluoroscopic (R/F) x-ray system w/ image intensification
*Dr.'s are able to observe the body's physiologic actions

Back 165

Fluoroscopy

***NOT intended to be used as a preview to positioning

Front 166

*digital detector technology is replacing film/screen technology
*has been used in CT
*photostimuable plates (PSP) - sheet inside the cassette
*PMT changes light into electronic signal

Back 166

Digital Imaging

*CR uses plates/cassettes
*DR does not use cassettes