Grids

Front 1

as thickness of an area increases

2

Back 1

kVp must be increased

More scatter radiation

Front 2

greater exposure to patient, holder and decreased contrast(clarity)

Back 2

Scatter

Front 3

Grids are used to decrease scatter which _______ the contrast

Back 3

increases

Front 4

Grid is placed between the ____ and the cassette

Back 4

patient

Front 5

Grids may be

2

Back 5

part of cassette

part of xray table

Front 6

Stationary Grids (bucky) remain still when xray is taken so lead lines are _________on finished xray

Back 6

visible

Front 7

Increased clarity for thicker areas

ability to radiograph large animals above the limbs

Back 7

Advantages of grid use

Front 8

Relationship between the height of lead strips and the distance between them

Back 8

grid ratio

Front 9

our grid is ______ lines per cm

Back 9

103

Front 10

this grid has excess absorption of primary beam near the edges

Back 10

Linear Grids

Front 11

Lead strips angled so they focus on central point Greatest amount of primary beam reaches the film

Back 11

Focused

Front 12

grid is more expensive and requires higher exposure factors. Less common in animals

Back 12

Crisscross Grid

Front 13

Occurs when there is an excess amount of useful x-rays that are prevented from reaching the film

Back 13

Grid Cut Off

Front 14

Wave of motion of electric and magnetic feilds

Wave contains discreet packets of energy called photons

Back 14

Electromagnetic Radiation

Front 15

3 things that can happen when radiation contacts tissue

Back 15

1. No effect

2. Cell damage-Repairable or non-repairable

3. Kill the cell

Front 16

MPD

Back 16

Maximum permissible dose

Front 17

How we measure radiation

radiation absorbed dose- energy absorbed per gram of tissue

Back 17

RAD

Front 18

unit of absorbed dose which produces the same biological effect as 1 rad of x-rays

Back 18

REM

Front 19

background radiation ___ mSv per year

Back 19

2

Front 20

xrays ______ mSv per year

Back 20

0.5-0.7

Front 21

LD 50 radiation for man

Back 21

4000 mSv

Front 22

cell changes with whole body exposure to decrease leukocyte count

Back 22

200-1000 mSv

Front 23

Cell changes with whole body exposure to cause vomiting and diarrhea

Back 23

1000-2000 mSv

Front 24

In vet radiology we are concerned with radiation exposure that is

3

Back 24

low dose

short time

small % of body exposed

Front 25

Maximum permissible whole body dose per year in Canada

Back 25

20 mSv

Front 26

Gloves reduce exposure by

Back 26

25%

Front 27

0.001-0.005 mSv produced per ____

Back 27

x-ray

Front 28

4 methods to measure radiation

Back 28

Film Badges

TLD

Optically stimulated

Ion Chambers

Front 29

Xrays are a form of _____ or ionizing radiation

Back 29

electromagnetic

Front 30

Knocks electron in the target and out of its orbit and another electron fills the inner orbit

Back 30

characteristic radiation

Front 31

Electron is slowed and loses energy as an xray photon

Back 31

Bremsstrahlun

Front 32

strength of the xray beam is not consistent through out the beam

Intensity of xray produced from the anode is greater towards the cathode

Back 32

Heel Effect

Front 33

Occurs when potential between anode and cathode is not high enough to pull electrons to anode

Back 33

Tube electroplating

Front 34

provides the electrical power to heat the cathode filament

Back 34

Low voltage circut

Front 35

intensity of the xray beam is inversely proportional to the square of the distance from the source

Back 35

Inverse Square Law

Front 36

REM

Back 36

roentgen equivalent man

Front 37

Sievert =

Back 37

100 REM

Front 38

RAD

Back 38

radiation absorbed dose

Front 39

gray

Back 39

100 rad

Front 40

ALARA

Back 40

As low as reasonably attainable

Front 41

TLD

Back 41

thermo luminescent dosimeter

Front 42

OSL

Back 42

Optically Stimulated Luminescence

Front 43

Pelvis mAs

Back 43

10

Front 44

Abdomen mAs

Back 44

7.5

Front 45

Limbs and thorax mAs

Back 45

5

Front 46

If xray is too dark when creating a technique chart we can _____

Back 46

decrease mAs by 30-50 or decrease kVp by 10-15

Front 47

Intensifying screens consist of a plastic base with ______ crystals which fluoresce and emit light when exposed to energy

Back 47

Phosphor

Front 48

Most common phosphor crystals are ___

Back 48

calcium tungstate- blue light

Front 49

Large crystals and thicker emulsions will emit more light so they are ____

Back 49

fast screens

Front 50

Small crystals and thin emulsions will emit less light so are _____

Back 50

slower screens

Front 51

Thin clear outermost layer of a film

Back 51

protective gelatin

Front 52

crystal emulsion in a gelatin base. crystals are sensitized by exposure to energy

Back 52

Silver halide/ Bromide

Front 53

Alkaline chemical reaction

converts latent image to visual

silver hallide crystals to black

Back 53

Developer

Front 54

converts exposed crystals of silver/halide bromide to black metallic silver

Back 54

Developing Agent

Front 55

Increase pH to alkaline level

softens and swells films emulsion layers

Back 55

Acceleerators

Front 56

Prevent rapid oxidation of the developer so a stable developing ratio can be maintained

Back 56

Preservatives

Front 57

Ensure unexposed silver halide bromide crystals are not effected by develper

Back 57

Restrainers

Front 58

Water- needed to dissolve chemical

Back 58

Solvent

Front 59

Acid chemical reaction

stops further developing reaction

removes unexposed crystals

hardens gelatin

Back 59

Fixer

Front 60

dissolves and removes unexposed silver halide crystals

Back 60

Fixing agent

Front 61

Prevent decomposition of fixing agents

Back 61

Preservatives

Front 62

Prevent film from getting water logged

Back 62

Hardeners

Front 63

usually acetic acid which neutralizes any developers still on the film

Back 63

Acidifiers

Front 64

Water- dissolves chemicals,

Back 64

solvent