digital & film radiography Flashcards
what type of radiography is mostly used?
didgital althoigh film can still be used in some GDPS and dental hospitals
what type of xray receptor is used in digital? and is it multiple or single use?
Phosphor plate
All multiple-use
what type of xray receptor is used in film? and is it multiple or single use?
Direct action film
All single-use
When the X-ray beam passes through an object some of the X-ray
photons are attenuated, creating an?
xray shadow
what does DICOM stand for and what do they do?
Digital Imaging & Communications in Medicine
handle digital medical images
Allows imaging to work between different software, machines,
manufacturers, hospitals & countries without compatibility issues
* Stores other important data alongside image
* eg. patient ID, exposure settings, date of image
what is PACS?
A medical imaging technology which provides storage & access to
images (typically in a healthcare organisation)
Note: hospital PACS not connected to dental practices
what are Types of digital (intra-oral) receptor?
CMOS sensor
Phosphor plate
what is a phosphor plate and how does it work?
a digital receptor
After receptor is exposed to X-rays, it must be put in a scanner
& “read” to create the final image
not connected to a computer
what is CMOS?
a digital receptor
Connected to computer
image created & immediately read within
the sensor itself Final image created virtually instantly
what is the identification dot?
Located in corner of receptor to aid orientation of image
Only effective if receptor is positioned correctly during
exposure
how would you carefully handle a xray receptor?
Hold the receptors by their edges, not by their flat surfaces
what are the differences between Phosphor plates and solid-state sensors?
phosphor plates are
Thinner, lighter Wireless
where as solid state sensors are
Bulkier & rigid Usually wired
what are two Extra-oral digital receptors?
phosphor plates
solid-state sensor
what does an intra oral film packet consist of?
inner paper
dental film
inner paper wrap
lead foil backing
outer package
what is the function of the lead foil?
Absorbs some excess X-ray photons
what is the function of the protective black paper?
Protects film from light exposure,
damage by fingers, & saliva
Crystals microscopic & are what effectively become the “pixels” of the
final image are called what?
Silver halide crystals
how does radiographic film work?
Photons interact with emulsion on film to produce latent image which
only becomes visible after chemical processing
what is the film speed?
faster film but poorer image quality
what do intensifying screens do in film radiography?
Reduce radiation dose
* But also reduce detail
what are the film processing steps?
Developing
➢ Converts sensitised crystals to black metallic silver particles
2. Washing
➢ Removes residual developer solution
3. Fixing
➢ Removes non-sensitised crystals
➢ Hardens emulsion (which contains the black metallic silver)
4. Washing
➢ Removes residual fixer solution
5. Drying
➢ Removes water so that film is ready to be handled/stored
digital radiography advantages and disadvantages?
adv- No need for chemical processing
Easy storage & archiving of images
Easy back-up of images
Easy transfer/sharing of images
dis adv- Requires diagnostic-level computer monitors for optimal viewing
Risk of data corruption/loss (solved by backing up)
Image enhancement can create misleading images
