Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Radiology > Image Receptors 2 > Flashcards

Image Receptors 2 Flashcards

1
Q

what is the purpose of the films outer plastic?

A

keeps film dry, saliva free
protects film from light damage and fogging
ensures orientation is correct

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the purpose of the film black paper?

A

protects film from light leakage
stiffens and supports film
prevents crimp and pressure mark

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the purpose of the lead foil?

A

composed of mixture of lead/aluminium
readily absorbs xrays
prevents back scatter
has distinct pattern embossed in lead

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

film components?

A 
base - plastic - polyester 
blue antiglare tint
adhesive layer
double emulsion
protective gelatin layer
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is in the emulsion?

A

silver halide crystals in gelatin
silver bromide/silver iodide/combo of two
gelatin allows even distribution
gelatin absorbs liquid readily allowing processing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the purpose of the adhesive layer?

A

sticks emulsion to base

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what does the super coat provide?

A

additional gelatin protective layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how is an image produced on film?

A

xrays hit silver halide crystals in emulsion
silver halide crystal becomes sensitised
latent image produced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is a latent image?

A

a pattern produced in the emusion by the sensitising of the crystals by xrays
not visible to the naked eye but becomes visible by chemical reactions during processing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is the main reaction during processing?

A

the reduction of silver bromide crystals to black metallic silver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is the film speed?

A

the sensitivity of the film to the xrays

larger crystals = larger speed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what would the dose be like for a fast film?

A

lower amount of xrays required to produce the film

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what size of crystals give reduced detail?

A

large crystals/ fast film

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are the layers of an intensifying screen?

A

base, reflective layer, phosphor layer, supercoat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the base layer made from?

A

polyester

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what happens in the phosphor layer?

A

fluorescent phopshors emit light when excited by xrays

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is the purpose of the supercoat?

A

protects phosphor layer from damage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is the consequence of the reduced dose used?

A

less detail

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

sequence of image production in indirect film?

A

xray hits phosphor crystal in intensifying screen and gives off light
light hits silver halide crystals in film emulstion
silver halide crystals are sensitised
latent image

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is the light produced from the intensifying screen in proportion to?

A

directly proportional to the energy in the xray phtoton

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

how to store film?

how to prevent use of old film?

A

cool dry place away from radiation

stockroom rotation

22
Q

3 methods of film processing?

A

automatic, manual, instant

23
Q

steps of processing?

A 
develop - make latent image vis.
wash - remove developer from film
fix - make image permanent
wash - stop fix and remove residual layer
dry - easier handled, prevent damage
24
Q

stages in a automatic processor?

A 
feed in rollers
developer rack
fixer rack
wash rack
dryer
25
Q

what stages in the automatic processor uses squeeze rollers?

A

developer rack, fixer rack, wash rack

26
Q

what happens during developing?

A

sensitised halide crystals are acted upon by developing agents, phenidore and hydroquinone
reduction of silver bromide to silver +bromide

27
Q

what are the activator agents?

A

calcium carbonate - controls activity of developing agents

28
Q

what is the restrainer agent?

A

potassium bromide - stops development of unexposed crystals

29
Q

preservative agent?

A

sodium sulphite- slows down oxidation

30
Q

solvent?

A

water

31
Q

what is the temp of a developer?

A

each developer has its own optimum working temperature

32
Q

too long in developer?

too short in developer?

A

dark

light

33
Q

too hot in developer?

too cold in developer?

A

dark

light

34
Q

concentration too strong?

too weak?

A

dark

light

35
Q

what does the fixing agent do?

A

fixing agents change unexposed silver halide to soluble compound so they can washed away
acid maintains the pH and neutralises the developer

36
Q

what is the cleaning agent?

A

ammonium thiosulphate

37
Q

what is the acidifier?

A

acetic acid - maintains pH

38
Q

what is the hardener?

A

aluminium chloride

39
Q

what is the preservative?

A

sodium sulphite

40
Q

an over fixed image?

A

image is removed from the film

41
Q

an under fixed image?

A

green tinge- does not archive

42
Q

when does wash happen in a manual processer?

automatic processer?

A

dev/fix, fix/dry

between fix and dry

43
Q

what does wash do?

A

stops action of developer, reduces carry over of material

removes unexposed crystals once made soluble by the fixer

44
Q

what happens when there’s insufficient washing?

A

film will feel tacky
green/silver appearance
dont archive well - image deteriorates

45
Q

drying film reduces possibility of what?

A

damage to emulsion

46
Q

why is an automatic processor good?

A

its consistent
less operator dependent
temp controlled, time controlled
less damage to film

47
Q

why is a manual process good

downsides?

A

done well = as good as automatic

very operator dependent, time needs to be accurate

48
Q

advantages of instant processor?

disadvantages of instant processor?

A

quick, convenient

large amount of chemicals to be disposed of, films dont archive well

49
Q

what is COSHH?

A

control of substances hazardous to health regulation

50
Q

danger with fixer?

A

corrosive and can release sulphur dioxide/ammonia on contact with strong acid/alkali

51
Q

make sure what is in place when using a processor?

A

ventilation - 10 room volumes/hour

Radiology (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions