RADIOLOGY DANB Flashcards
ALARA
As Low As Reasonably Achievable
the positive ion of the x-ray
Anode
“the angle” technique” an imaginary line bisects the angle formed by the long axis of the tooth.
Bisecting
What cone do you usually use when using the bisecting technique?
Short cone
shows upper and lower teeth in occlusion. (used to detect inter proximal caries)
bitewing
a negative electrode where electrons are emitted.
Cathode
extraoral radiographs to study the face and jaws.
Cephalometric
made of a lead diaphragm, limits or restricts the size of exposure, 2.75in.
Collimation
shades of gray; increases kVp darkens the radiographs and produces more shades of gray
Contrast
darkness of a radiograph
Density
What is directly related to mA?
Density
a negatively charged particle that travels around the nucleus of an atom.
Electrons
length of time that x-rays are produced
Exposure Time
a monitoring device a clinician wears to monitor radiographic dosages
Film Badge
from film to focal point of anode - 8, 12, and 16 inches most common.
Focal Film Distance
removes the unexposed silver halide crystals from the emulsion on the film.
Fixer
intensity of the primary beam DECREASES in proportion to the square of the distance from the source.
Inverse Square Law
QUALITY = penetrating power of the x-ray beam
Kilovolt Peak (kVp)
What is the maximum permissible does that clinicians should recieve?
5 REMS/year (0.05 Sv)
QUANTITY = number of x-rays or radiation produced, increasing the mA darkens the radiograph
Millamperage
an extraoral radiograph that produces an image of the entire dentition along with the supporting tissues and the lower portion of the facial structures.
Panoramic
image that shows the entire tooth from incisal edge to the apex of the root.
Periapical
located at the end of the tube head and used to AIM the primary x-ray beam at the film or sensor.
PID - position indicating device
the main x-ray beam which records the image on the film or sensor.
Primary Radiation
a measurement of radiation that is absorbed
RAD- Radiation Absorbed Dose
(black or dark) areas on radiographs of images that are NOT AS DENSE.
Radiolucent
Name some radiolucent areas in the oral cavity
pulp, sinus chambers, foramens
(white or light) areas of radiographs that ARE MORE DENSE.
Radiopaque
Name some radiopaque areas within the oral cavity?
Bone, amalgam or composite restorations
a measurement of radiation in man
REM - radiation equivalent man
“scatter radiation” = x-ray beams that are deflected everywhere and are harmful
Secondary Radiation
energy that comes from high speed electrons
X-ray
Who discovered the x-ray?
Wilhelm Conrad Roentgen
Who is thought to have taken the first dental radiograph on a living subject in the U.S.?
Dr. Kells
Who is the first to expose a prototype of a dental radiograph?
Dr. Otto Walkhoff
Who is the first to alert the dental field to the dangers of radiation exposure?
Dr. Rollins DDS
Who introduced the hot cathode tube in 1913?
William David Coolidge
What are the 2 basic techniques utilized in intraoral radiography
Bisecting & Paralleling
anything that occupies space and has mass
matter
the ability to do work and overcome resistance
energy
the smallest part of an element that still retains the properties of that element
atom
the chemical combination of 2 or more atoms that forms the smallest particle of a substance and still retains the properties of that substance.
Molecule
an electrically charged particle, either positive or negative
ion
a pair of ions, 1 positive & 1 negative
ion pair
the formation of ion pairs
ionization
the emission and propagation of energy through space or through a material medium in the form of electromagnetic waves
Radiation
radiation that is capable of producing ions
Ionizing Radiation
The process whereby certain elements undergo spontaneous disintegration or decay; this process causes the emission of one or more types of radiation.
Radioactivity
the alternate form of an element, having the same # of protons but a different # of neutrons within the nucleus
Isotope
bundles of energy that travel through space at the speed of light
Photons
the distance between 2 waves from crest (top) to crest
Wavelenth
how are wavelengths measured ?
Angstrom units
the number of waves that pass a given point per unit of time
Frequency
the higher the frequency, the ______ penetrating the radiation
more
the speed of the wave
velocity
Long wavelengths = ______ Frequency = ______ Penetrating X-rays
Low, Less
Short wavelengths= _______ frequency = ________ Penetrating X-rays
High, More
Name the properties of x-rays
invisible consist of minute bundles of photons travel in straight lines travel at the speed of light have no mass or weight have no charge can penetrate tissues & structures can affect photographic film can effect biological tissue
radiation that is always present in our environment
Background radiation
allows movement for positioning the tube head; has a hollow center that holds the electrical wires running from the control panel to the tube head
Tubearm/ Extension Arm
Attached to the tube arm by means of a yoke; houses the dental x-ray tube and transformers
Tube head
What is the tube head generally made out of?
Aluminum
determines the amount of electrons within the hot cathode tube that will available for x-ray production
mA
mA=
quantity
kVp=
quality
determines the speed at which the electrons within the tube are traveling and thus determines the penetrating ability of the x-rays produced
Kilovolt peak - kVp
How far away must you be fro the area you are exposing?
6 feet
where is the source of electrons being produced within the x-ray tube?
cathode
stops the electrons traveling from the cathode and converts their energy into electromagnetic radiation (x-rays)
anode
cell damage results when ionizing radiation directly hits critical areas within a cell
direct theory
cell damage results indirectly when x-rays cause the formation of toxins in the cell; toxins in turn cause cell damage
indirect theory
a substance or tissue that is relatively susceptible to injury by ionizing radiation
radiosensitive
a substance or tissue that is not easily injured by ionizing radiation
radioresistant
What cells are the most radiosensitive?
bloodcells, reproductive cells, epithelial cells
What cell are the least radiosensitive?
Muscles cells, brain cells, bone & nerve cells
name the 2 main types of cells in the body
genetic & somatic
the amount of radiation that is sufficient to cause death to an organism
lethal dose
1 sievert = _________
100 Rem
1 girl named Sievert paid $100 to go to the REM concert
1 gray = _______
100 rads
1Gray purse for $100 because it was so rad
restricts the size and shape of the useful beam
collimation
What is the purpose of the rectangular PID?
Reduces patient radiation exposure by up to 70%
