Digital vs Film

Question 1

effects of number of pixels on image

Answer 1

more pixels, better detail, higher resolution

more storage, more cost

Question 2

DICOM

Answer 2

format of digitals
digital imaging and communications in medicine

Question 3

PACS

Answer 3

picture archiving and communication system

Question 4

2 types of intra oral digital receptors

Answer 4

phosphor plates
solid state sensors

Question 5

how are phosphor plates used for xray

Answer 5

IO digital
not connected to computer, put in scanner

phosphor crystals excite via xray energy, creating latent image

laser in scanner causes phosphor crystals to emit visible light

Question 6

how are solid state sensors used for xray

Answer 6

IO digital

connected to computer
latent image created and immediately read within sensor
image created instantly

Question 7

phosphor plates summary

Answer 7

thinner, lighter, flexible
wireless

variable room light sensitivty
risk of impaired image
needs processed in scanner

Question 8

solid state sensory summary

Answer 8

more durable
image quickly
smaller active area
no issue with room light control

wired
expensive
bulkier
rigid

Question 9

radiographic film

Answer 9

where image formed
sensitive to photons and visible light
photons interact with emulsion on film to produce image
only visible after chemical processing

Question 10

components of radiographic film

Answer 10

emulsion -
silver halide crystals in gelatin [shields from mechanical damage]

plastic base

adhesive

lead foil -
absorbs excess xray photons

Question 11

importance of silver halide crystals in film radiography

Answer 11

pixels of image
silver bromide

becomes sensitised with xray/light photons interaction

sensitised crystals converted to particles of black metallic silver = dark
non sensitised removed = light

Question 12

effect of number/size of silver halide crystals

Answer 12

larger crystals = faster film = poorer image quality

Question 13

intensifying screen

Answer 13

indirect action film for E/O

reduces radiation dose,
reduces detail

Question 14

stages in film development

Answer 14

1. developing
   - converts sensitised crystals to black metallic silver
2. washing
   - removes residual developer solution
3. fixing
   - removes non sensitised cystals, hardens emulsion
4. washing
   - removes residual fixer solution
5. drying
   - removes water so film is ready to be handled/stored

Question 15

types of film processing

Answer 15

manual
automated
self developing films

Question 16

manual/wet cycle

Answer 16

different types of chemicals
dark room
adequate ventilation

Question 17

automated film cycle

Answer 17

machine
faster and more controlled
no need for dark room
expensive

Question 18

self developing films

Answer 18

not reccommended
no dark room or processing
faster

poor image quality
deteriorating image
no lead foil
easily bent
difficult to use
expensive

Question 19

processing issues in film radiography

Answer 19

developing -
affected by time, temp, conc
oxidisation in air, less effective over time
needs replaced regularly

pale image -
exposure issue, cannot develop due to removal from solution too early, too cold, too dilute, too old
[opposite = dark image]

fixing -
inadequate means non sensitised crystals left behind, image is greenish/yellow, milky and browns over time

washing -
developer/fixing solution continues to act if not washed off

Question 20

film storage issues

Answer 20

takes up room
needs to be accessible and safe from damage
reliable system needed to organise to be found and reduce risk of being lost/mixed up

Question 21

digital vs film

Answer 21

no need for chemical processing
easy storage/archiving
easy back up
integrated to pt notes
easy transfer/sharing
images can be manipulated

worse resolution = risk of pixelation
risk of data corruption/loss
hard copy prints have decreased image quality
image enhancement can create misleading images