RAD 1 Flashcards
anode
a positive electrode in the xray tube
atom
a basic unit of matter
automatic processor
an automatic xray film processor that moves film from one solution to the next automatically
beam alignment device
assists in positioning of the PID
bitewing
an image view showing the crowns of both arches on one film
calcium tubgstate
a common type of phosphor
cathode
a negative electrode in the xray tube
charge coupled device (CCD)
solid state image sensor in intra-oral digital imaging
central ray
xray at the center of the beam
cephalometric film
xrays used for ortho treatment to show the bony and soft tissue areas of the face
contrast
differences in degrees of blackness on a radiograph
density
overall blackness of darkness of a radiograph
dental radiography
process of recording images of the teeth and adjacent structures by exposure to radiation
digital image
an electronic picture taken by sensors and displayed on a monitor
digital imaging
a filmless method of capturing an image and displaying it by using an image sensor
digitize
scanning of traditional film-based radiographs into a digital image
distortion
a change in the size of an image caused by incorrect angulation
dose (of radiation)
amount of energy absorbed by tissues
dosimeter
a device used to detect and measure an accumulated dosage of radiation
duplicating film
designed to duplicate film in a duplicating machine
electron
a negatively charged particle in an atom
emulsion
a coating on the xray film with energy sensitive crystals
energy
ability to do work
extra oral film
film that is placed outside of the mouth
film speed
sensitivity of the emulsion on the film to radiation
genetic effects
effects of radiation that are passed on to future generations
identification dot
identifies how the plates or film shout be positioned in the mouth or when mounting
image
can be film based or digital and produces recordings of an image
image receptor
a recording medium for an image
intensifying screen
a device used to convert xray energy into visible light which exposes screen film
intensity
total energy of the xray beam
intraoral film
film designed for placement in the mouth
ion
an electronically charged particle that is unstable
ionization
process where electrons are removed from atoms, causing harmful effects of radiation to humans
ionizing radiation
radiation that produces ionization, resulting in harmful effects
kilovoltage peak
highest voltage of radiograph used during radiograph exposures
label side
coloured side of the film that faces the tongue
latent
something is dormant
latent image
invisible image on the xray fil after exposure but before processing
latent period
time between exposure to radiation and appearance of the image
light-tight
used to describe the darkroom where no light can be present
magnification
proportional enlargement of a radiographic image
matter
anything that occupies space and has form or shape
milliampere
a unit of measurement used to describe the intensity of an electrical current
occlusal radiograph
radiographic image that shows large areas of the max and mand
panoramic film
image that provides a full view of the upper and lower jaws
penumbra
blurry or fuzzy appearance of radiograph
periapical
image that shows the crown, root tip and surrounding structures
photon
tiny bundles of pure energy that has no mass or weight
primary beam
most penetrating beam produced at the target of the anode when exposing a radiographic image
primary radiation
xrays that come from target of the xray tube
processing
a series of steps that transform exposed film into a radiographic image
radiation
forms of waves of energy emission through space or material
radiograph
image produced on photosensitive film by exposing film to radiation, and processing it
radiology
science of the study of radiation used in medicine
safelighting
low intensity light on the red-orange spectrum that is used as illumination when processing films
scatter radiation
type of secondary radiation that occurs when xray beam has been deflected from its path by interacting with matter
secondary radiation
radiation that is created when the primary beam interacts with matter
sensor
an image receptor that contains a silicon chip with an electric circuit
sharpness
measure of how well the radiograph reproduces the fine details or outlines of an object
somatic effects
effects of radiation that causes illness and affects the body tissue but is not passed to future generation
tube side
solid white side of film that faces the xray tube
xradiation
high energy inonizing magnetic radiation
what are the uses of dental images
- detects dental caries
- identifies bone loss
- abnormalities
- growth and development
- documents pt condition
who discovered radiography and when
wilhem conrad roengten in 1895
when was the first dental radiograph
1896 by O. Walkhoff
when was the first dental radiograph on a live patient
1896 by C.E Kells
what is the difference between an atom and an ion
an atom is a basic unit of matter
an ion is an electrically charge particle
explain the difference between short wavelength and long wavelength and what is the preferred creation of xrays
the difference is the distance of each crest of wave within a given period of time
- short wavelengths are preferred
what are the parts of the dental xray machine and fucnctions
control panel
- turns machine on and off
- and controls exposure time, kilovoltage and milliamperage
extension arm
- runs wires and elecetrical current from the control panel to the tubehead
tube head
- produces the xrays
tube head seal
- keeps the oil in the tube head and acts as a filter for xray beams
xray tube
- produces the xrays, has a cathode side and an anode side
transformer
- alters the voltage of incoming electrical unit
aluminum filter or disk
- lowers the xray beams directed to patient
lead collimator
- controls the size and shape of the xray beams as it leaves the tubehead
pid
- open ended, lead lined cylinder used to aim xray beam
what is in the xray tubehead and what is it made of
contains the xray tube which is made of leaded glass and has a window that allows xray beams to exit
- consists of negative side; cathode, which consists of the tungsten filament in a cup shaped holder made of molybdenum
- also has a positive side; anode, which consists of the tungsten target that is embedded in a solid copper rod
what are the exposure factors that can be changed on the control panel
milliampere, kilovoltage, and exposure time
what are the three types of radiation and how is it created
primary radiation
- radiation that occurrs before the radiation hits matter and is still in the tubehead
secondary radiation
- radiation that occurs when radiation beam comes in contact with matter
scattered radiation
- radiation that occurs when xray beams are deflected when it comes in contact with matter
describe radiolucent and radiopaque images and give examples of each
radiolucent images will appear dark or black
ex. dentin, air, foramens, sinuses, soft tissue
radiopaque images will appear light or white
ex. enamel, fillings, metal
what are the three xray beam characterisitcs and describe each one
quality
- used to describe the penetrating ability of the xray beam
- is measured in kPV, and needs betwen 80-100 kPv
- a change in this will result in dense and dark radiographs
quantity
- refers to the numbers of xrays produced in the xray unit
- should be from 8-17 mA
- settings above this will cause overheating
intensity
- a combination of number of xray photons and energy of each photon
why are effects of ionixing radiation harmful to human tissue
- produces biologic changes in living tissue
what is the difference between acute and chronic radiation exposure
acute - exposure occurs in large dose in short period of time
chronic - exposure occurs in small repeated doses over a longer period of time
explain the difference between genetic and somatic effects of radiation
genetic - when damageds occur and may be passed to future generations
somatic - when damages occur to the body tissues and cannot be passed to future generations
what are critical organs with dental rad
eyes, skin, bone marrow, thyroid, salivary glans, gonads,
what is the permissible dose for an occupational worker and a non-occupational pers
occupational workers - 5.0 rems
non-occupational - 0.1 rems
what are radiation protective devices, and or measures and how they limit exposte
film badges, pocket dosimeter - measures the exposure you have encountered ensuring you do not excel this limit
not standing in primary beam and standing minimum 6 feet away
ALARA - radiation must be as low as reasonably achievable
what are the disadvantages of digital imaging compared to conventional xrays
cost
converting previous records to digital
learning the computer softwares
power going down or software issues
what is the difference between direct and indirect imaging, and list typs of each
direct imaging
- take a radiograph and it automatically is put on the computer without having to process the image
- CCD
indirect imaging
- captures a radiograph that will need to be processed and mounted
- PSP plates or film
what are the differences and similarities between receptor posiitioning instruments and beam alignment devices
receptor positioning instruments hold the film or plates in place while taking xrays
beam alignment devices also hold film and plates in place, but also aligns the beam into proper positioning
what are the enhancements that can eb applied to digital images by computer software
contrast
brightness
image size
sharpness
inverion
pseudocolour alteration
what are the various layers of the intra oral film and what they are composed of
black paper film wrapper
- shields film from light
thin lead foil
- shields film from scattered radiation
outer packet wrapping
- made of soft vinyl and seals the film packet
how does a latent image form on a radiographic film
radiation interacts with the silver halide crystals in the film emulsion
what factors of film speed are necessary for fast speed film
larger sized crystal halide crystals
what is the function of identification dot on the film packet and on the film
identification dot on the film packet refers to the left or ride side of the film
on the film, it is required for positioning of film when mounting
what intraoral film sizes are for 0-4
0 = for children under the age of 3
1 = for anteriors of children and adults
2 = for bitewings for adults and PA
3 = for bitewings that must include both pre molars and molars
4 = for the max and mand arches
what are the differences between intraoral and extraoral film, and list the types of each one
intraoral film is places inside the mouth to view the teeth and jaw
- film and psp plates
extraoral is placed outside of the mouth and is used to examine large areas of the head or jaw
- panoramic and cephalometric
explain screen films and the used of intensifying screens in cassettes
screen films are more sensitive to the light than radiation which uses less radiation for patients
intensifying screens increase the effect of radiation
criteria for storing film
should be stored according to manufacturers instructions
kept away from radiation
50-70 f
30-50% humidity
what are the steps in order of manual film processing
developing - reduces the exposed silver halide crystals and softens emulsion
rinsing - removes developer from film so developing process stops
fixer- removes unexposed silver halide crystals and hardens film emulsion
washing- removes residue of fixer
dry- air dries the film
advantages of automatic processing over manual
requires less time
less equipment and space
less errors
difference between replenishing and replacing
replenishing is adding liquid to ensure same level is maintained - should be done daily
replacing - getting rid of old materials and putting new set - should be done every 3-4 weeks
describe the dark room setting and all necessary equipment
dark room may not have any light leaks present
lights must be turned off
safe light must be used for illumination while processing images, must be minimum of 4 feet away from work space
list all processing errors that could appear on xrays and how each will appear
- Time and temperature errors
Can appear light, film is underdeveloped
o Can appear dark, film is overdeveloped
o Can have cracks, reticulation of emulsion - Chemical contamination
o Dark or black spots, developer spots
o Light or white spots, fixer spots
o Yellow-brown spots, old developer - Film handling
o Straight white border, developer cut off
o Striaght black border, fixer cutoff
o White or dark areas, film is overlapping
o White spots, air bubbles or water bubbles
o Black crescent shape, finger nail artifcate
o Back finger prints, finger print artifact
o White lines, scratches on film
o Thin black branches, static electricity - Lighting
o Black, light leak
o Grey and lacks detail and contrast, fogged filmree
