Digital vs Film Flashcards
effects of number of pixels on image
more pixels, better detail, higher resolution
more storage, more cost
DICOM
format of digitals
digital imaging and communications in medicine
PACS
picture archiving and communication system
2 types of intra oral digital receptors
phosphor plates
solid state sensors
how are phosphor plates used for xray
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
how are solid state sensors used for xray
IO digital
connected to computer
latent image created and immediately read within sensor
image created instantly
phosphor plates summary
thinner, lighter, flexible
wireless
variable room light sensitivty
risk of impaired image
needs processed in scanner
solid state sensory summary
more durable
image quickly
smaller active area
no issue with room light control
wired
expensive
bulkier
rigid
radiographic film
where image formed
sensitive to photons and visible light
photons interact with emulsion on film to produce image
only visible after chemical processing
components of radiographic film
emulsion -
silver halide crystals in gelatin [shields from mechanical damage]
plastic base
adhesive
lead foil -
absorbs excess xray photons
importance of silver halide crystals in film radiography
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
effect of number/size of silver halide crystals
larger crystals = faster film = poorer image quality
intensifying screen
indirect action film for E/O
reduces radiation dose,
reduces detail
stages in film development
- developing
- converts sensitised crystals to black metallic silver - washing
- removes residual developer solution - fixing
- removes non sensitised cystals, hardens emulsion - washing
- removes residual fixer solution - drying
- removes water so film is ready to be handled/stored
types of film processing
manual
automated
self developing films
manual/wet cycle
different types of chemicals
dark room
adequate ventilation
automated film cycle
machine
faster and more controlled
no need for dark room
expensive
self developing films
not reccommended
no dark room or processing
faster
poor image quality
deteriorating image
no lead foil
easily bent
difficult to use
expensive
processing issues in film radiography
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
film storage issues
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
digital vs film
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
