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85 terms

Radiology Part-1- MDC Dental Hygiene

STUDY
PLAY
diagnosis, treatment planning, and evaluation.
X-rays are used for?
Photons
X-rays AKA?
Electromagnetic
X-rays are _________because they differ from each other by their wavelength.
Wavelength
Its measured from the top of one crest to the top of another crest.
True
True/False: The shorter the wavelength the more penetrating the x-rays.
Soft or Low energy rays
Longer wavelength x-rays AKA ?
Collimate and filter the non-useful long wavelength x-rays.
Whats the function of the primary x-ray beam?
Long wavelength, low energy x-rays.
Secondary radiation/rays AKA?
Scatter rays
Result when x-rays hit matter and scatter in different directions.
Radiopaque
Dense objects appear _________ .
Long wavelength rays
Secondary x-rays are ?
Tube head
X-rays are produced in the ?
- Cathode, + Anode
- electrode: ________ and + electrode :_______.
inside a glass envelope in the tube head.
Cathode and anode are located ?
cathode
Where is a tungsten filament located at ?
thermionic emission.
When the x-ray machine is turned ON the filament releases electrons that form an electron cloud, which is known as ?
focal spot (a target on the anode).
The electrons travel from the cathode to the anode and hit ?
Tungsten Target.
The focal spot is also referred to as ?
X-rays and heat
When the electrons from the cathode hit the tungsten target, energy is produced in two forms. ?
Heat (Be sure to remember this).
99% of the energy produced is _____and only 1% is in the form of x-rays.
The heat
The anode is embedded in copper to dissipate ?
True (Remember this)
True/False: Electrons only travel in one direction-from the cathode to the anode.
General Radiation or Bremsstrahlung (breaking) x-rays.
What is produced if the electrons are slowed or moved from their path when they collide with the tungsten target?
Characteristic Radiation.
What is produced when electrons from the cathode collide with atoms on the anode, and an electron is released from its shell causing electrons to shift to fill the space of the ejected electron ?
The answer is to eject an electron from its shell. That is because Characteristic radiation is more penetrating then General radiation.
Which do you think requires more energy—to eject an electron from its shell or to move an electron from its path?
Radiopaque.
If the x-rays have less energy they will have a greater chance of being absorbed by the object and as a result the object will appear more (radiopaque/radiolucent).
Anode
X-rays or photons are produced at the?
Characteristc radiation and Ionizing radiation.
Causes an electron to be ejected from its shell?
99%
The % of energy released as heat at the tangsten is?
Tungsten
The filter on the cathode is made of ?
Electrons
The cathode is the source ?
X-rays
The anode is the source of ?
Anode
The focal spot is part of the ?
Milliamperage(ampere)
Affects the number of electrons released by controlling the temperature of the filament at the cathode.
Film speed, exposure time and distance.
mA settings is determined by?
mA
Affects the density by influencing the number of x-rays that reach the film.
10-15
mA ranges from?
mA
Affects the quantity of electrons released.
Denser x-ray film.
The result of more rays reaching the film is ?
Proportional
Density and mA are?
Exposure
Its the length of time the x-rays are being produced.
Increased
As the exposure time is increased, the density of the film is (increased/decreased).
60 (similar to 60 minutes in 1 hour. One easy way to remember the conversion is to think of a clock. ¼ around the clock is 15 minutes and ¼ second equals 15 impulses. ½ way around the clock is 30 min.; ½ second equals 30 impulses. ¾ second equals 45 impulses.)
There are __ impulses in 1 second.
Kilovoltage (voltage)
Controls the quality of radiation.
PENETRATING x-rays
As the kVp is increased produces more ?
kVp
Influences the penetration and force/energy of x-rays.
cathode to the anode
kVp controls the speed the electrons travel from ?
65-110
The kVp setting on the control panel ranges from ?
Setting
Determined by the density of the object being exposed and the type of contrast desired.
kVp
Affects the contrast on the radiograph.
kVp
Inversely proportional to contrast.
90-100 kVp
Produces low contrast.(kVp?)
70 kVp
Produces high contrast.(kVp)
kVp, filtration, mA, exposure time and PID length
Factors that influence density by affecting the number of x-rays that reach the film.
1/2
Increasing kVp by 15 will reduce the exposure time by?
Increase
Increasing kVp; (Increase/decrease) density.
Increase
Increasing mA; (Increase/decrease) density.
Increse
Increasing exposure time; (Increase/decrease) density.
Decrese
Increasing film distance; (Increase/decrease) density.
Decrease
Increasing filtration; (Increase/decrease) density.
kVp and filtration
2 factors that influence contrast.
Decrease
Increase kVp;(increased/decrease) contrast.
Decrease
Increase filtration;(increased/decrease) contrast.
Panorex films
Yellow filter cannot be used with ?
RED
Filter that is used if both periapical and panorex exposures are processed.
If there is excessive safelight.(If the image of the coin can be seen there is too much safelight)
The coin test is used to determine ?
7 1/2 - 15
watt bulb ?
4 feet from the safelight.
The counter top should be at least ?
Developer (base)
Converts the new silver bromide crystals to black metallic silver .
Developer (base)
Softens the emulsion.
Developing
Most critical stage of processing?
The fixer (acid)
Removes undeveloped and/or unexposed silver bromide crystals.
The fixer (acid)
Hardens and shrinks the emulsion.
Distilled water
Solvent for both the fixer and developer
Developer
Alkaline (a base)
developing time is influenced the most by temperature
the thermometer is placed in the developer solution because?
reduced
if the temperature of the developer is increased, the developing time is ?
True
Films can be left in the fixer, or wash, for longer than the recommended time. (T/F)
5 mins - 68F (28C)
Processing Time/Temp?
Developer, fixera and water.
Order of processing for the automatic processor?
Rapid processing
films will lose definition over time and therefore cannot be used for permanent records
Endodontics and oral surgery
Rapid processing are used for ?
SLOB rule
Used to determine if an object is located on the buccal or lingual aspect of a radiograph.
same lingual; opposite buccal.
SLOB stands for ?
Mental and lingual nerves
Nerves that pass in the mental foramen?