Dental Radiology - Landmarks, Digital, + Film Processing (3) Flashcards
What is digital imaging
the filmless imaging system
How are sensors used for digital imaging
sensors obtain the image and directly transfer it to a computer with imaging software to display and modify
Digital imaging produces images that are
better than or equivalent to traditional intra oral radiographs
How does digital imaging reduce exposure
the sensors are more sensitive to radiation, and there is less chance of retakes being needed due to ability to modify
process of digital imaging
exposure to xradiation > electronic charge on sensor > travels through fiberoptic cord> digitized and presented instantly on screen
do you use the same placement techniques with digital sensors as you would traditional film
yes
the only thing that differs film from sensors is the
process of image production
ADC
analog digital converter
are the film sizes different for digital vs traditional
no
exposure times for sensors are ___ % less than film
50-90%
2 types of Digital imaging
direct and indirect
what is the difference of direct and indirect digital imaging
direct is sent instantly to the computer, indirect still has to be scanned into the computer with a separate machine
2 types of direct imaging
charge couple device (ccd) and complimentary metal oxide semiconductor (cmos)
CCD
charge couple device
CMOS
complimentary metal oxide semiconductor
APS
active pixel sensor
CMOS is aka
APS
what does a CCD do
releases electrons from silicon and produces electronic charge to create a latent image that is transferred and visible on a computer
CCD is a
solid state detector with a silicon chip and electric current embedded inside
How are images from a ccd made
with pixels forming arrangements on sensor
CMOS are similar to CCD but have one difference being
how the pixels are read
CMOS are claimed to have___
25% better resolution, low production cost, and durability compared to ccd
barriers must be used with all ___
digital sensors
Indirect digital imaging is
obtaining a digital image from film/sensor after exposure by running it through a scanner to convert data to digital format
phosphoric plates are a form of __
indirect digital imaging
what equipment do you need for indirect imaging
xray, psp plates, scanner, computer w/ software
2 types of indirect imaging
scanning traditional radiographs(with CCD camera and computer) and storage phosphor imaging (PSP)
what would the process of infection control be for scanning plates
gloves while removing and disinfecting plate, placed into transfer tray once clean, transferred to scanner with clean hands, new gloves on to put through scanner
Phosphor plates with immediately __ the image unless otherwise chosen
erase
how is a phosphor plate cleared after scanning
with a bright beam of light
Instant images are produced by
CCD and CMOS
Laser scanners are used on
phosphor plates
digital radiography is overall a ___ option
better, if applicable
film processing is the
steps needed to produce a permanent visible image on a radiograph
processing converts latent image to
visible
Steps of processing are
developer, rinse, fixer, wash, dry
development is to
reduce the exposed silver halide crystals
reduction is the
halide portion of exposed crystals are removed
rinsing between developer and fixer is necessary to
remove excess developer to stop process that develops shades of grey
fixing is to
remove unexposed radiopaque (white) crystals
elon is a ingredient in developer that helps
generate shades of grey
developers have what 4 ingredients
developing agent, preservative, accelerator, restrainer
you only rinse between fixer and developer when ___ processing
manually processing
what 4 ingredients are in fixer
fixing agent, preservative, hardening agent, acidifier
developer has a __ pH
basic
fixer has a __ pH
acidic
what kind of light is used when processing in a dark room
a safe light, red or orange
a safelight must be __ watts or less and at least __ ft away from machine
7 watts, 4 ft
optimum temp of solution for Manuel processing is
68 f
after agitating solution, how long do you place film in developer
4.5 - 5 mins
after removing film from developer and agitating, you rinse for ___ and place in fixer for ___
20-30 sec rinse, 10 mins in fixer
film is washed for __ minutes after taken out of the fixer
10 mins
_ and _ are controlled when automatic processing
time and temp
automatic processing is
less time, less equipment, less space
film in hot solution for too long results in a
dark film density
film in cold solution for not enough time results in a
light and bright film
reticulation is
pebbly web like appearance
why does reticulation occur
when moving film from a hot to cold environment or vice versa
dark spots are a result of
developer on film prior to processing
light spots are due too
fixer on film prior to processing
light brown yellow stains are due to
not enough washing time
white spots (radiopaque air bubbles) are due to
failure to agitate the film
overlapping images
fed into processor to fast
dark lines on film are from
dirty rollers
scratched film can be from
dirty rollers or incorrect handling
what is a fingernail artifact on film
a black cresent mark from operators fingernail
static electricity creates a
line/dot/branch/lightning bolt pattern due friction from removing to fast
fingerprint artifacts are created when
contaminated fingers touch film or wet film is handled
what is debris accumulation
dirt and dust accumulated on digital sensors from being improperly cared for
light leaks appear
black
fogged film appears
grey and lacking detail
what causes fogged film
expired film, hot developer, improper storage
overlapped contacts are due to
incorrect horizontal angulation
elongation occurs due to
not enough vertical angulation
foreshortened images are due to
to much vertical angulation
creasing or bent film appears as a
radiolucent (for film) or white (for PSP) lines on film
cone cuts occur when
the pid is not centred on the film
on digital film cone cuts appear
white and bright
on film cone cuts appear
clear
double exposed film is when
film is exposed twice without clearing, causing two images to appear
how do you handle film when mounting
with clean bare hands only touching the edges
what do you label a film mount with
patient name, dentist name, date of exposure, operators initials
anatomic order is
how the teeth are arranged within the arches
bone, enamel and dentin all appear
radiopaque
pulp, periodontal ligaments appear
radiolucent
gold, amalgam, composite and porcelain all appear
radiopaque
RCT appear as a ___ going down the roots
radiopaque
composite appears less radiopaque but still __ then enamel
darker
porcelain fused to metal crowns appear as a ___ with a radiopaque centre
radiolucent outline
parallel bone loss is the bone moving ___
downward of root
vertical/angular bone loss appears as a
dip in the bone away from one tooth
vertical/angular bone loss also creates a ___
deep pocket in gingiva
anterior nasal spine is located
above the incisive foramen
the split between the central incisors is known as the
incisive fossa/foramen
the nasal spine is located above the
nasal septum
the nasal septum is above the
central incisor root tips
median palatine suture is in line with the
incisive foramen between centrals
the nasal fossa is the fully ___ spaces next to nasal septum
radiolucent (black)
Between the nasal septum and the median palatine suture are the
nasal fossa and anterior nasal spine
the soft tissue shadow of the nose appears as a
light grey line below root at crown
the mental ridge is located on the
external side of the mandible under premolars and incisors, appears as a radiopaque band
mental fossa is radiolucent and appears above the
mental ridge
the mental foramen appears as a radiolucency in the
mandibular premolar region
the mandibular canal appears as a ___ band outlined by ___ lines below the molars
radiolucent band outlines by radiopaque lines
mylohyoid ridge is aka
the internal oblique ridge
where is the mylohyoid ridge located
from third molar down and forward to second premolar
submandibular fossa is located below the
mylohyoid ridge
