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45 Cards in this Set
- Front
- Back
What is the filter |
Absorbing material placed in the path of the x-ray beam
to remove a high percentage of the soft x-rays and reduce patient radiation dose. |
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What are the Functions of the Filter |
To remove high percentage of soft x-rays
Reduce patient radiation dose
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Inherent Filtration |
Built into the machine by the manufacture Includes the glass of the x-ray tube , insulating oil, and material that seals the port. |
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What does the Collimation do? |
Controls the size and shape of the useful beam |
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Where is the collimater placed |
In the path of the primary beam as it exits the tube housing at the port |
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What is the purpose of the Collimater |
Th reduce radiation dose by reducing the volume of tissue exposed
Reduces scatter radiation that causes poor contrast to the radiograph |
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What is total filtration? |
The sum of inherent and added filtration expressed in millimeters of aluminum equivalent |
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Present safety standards require an equivalent of what when x-rays are operating ranges below 70 |
1.5mm aluminum |
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Present safety standards require an equivalent of what when x-rays are operating ranges above 70 |
minimum 2.5 mm aluminum |
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Added Filtration |
The placement of the aluminum discs in the path of the x-ray beam between the port seal of the tube head and PID |
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Round Collimator restricts the x-ray beam to what |
2.75in |
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Rectangular Collimator restricts the x-ray beam to what? |
Approximate size of the image receptor |
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Rectangular Collimator reduces a patients exposure up to what percent |
70% |
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The longer the PID the less or more radiation |
Less |
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What speed of film is the most effective for reducing radiation |
Fast |
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What are the 3 speed Groups? |
D, E and F |
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What speed of film is the fastest? |
F |
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How much faster is the E film from the D film |
Twice as fast and requires only 1/2 the exposure time |
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How much more can the F speed film reduce radiation compared to the E speed film in percentage? |
20% |
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How should lead and lead equivalent aprons be stored |
Flat or hung unbent |
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What does the thyroid collar protect |
Thryoid gland, and other radiosensitive tissue in the neck region |
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What are the methods to protecting the patient from radiation |
Evidence based prescribing Communication Working knowledge Education Selection of technique Posted exposure factors Filtration Collimation Open ended, 16 inch rectangular PID F-speed film Image receptor holders Lead aprons Thyroid Collars Darkroom protocol |
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What should be used to hold the film devices in place? |
Image receptor holding device |
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What are the three choices that can be taken instead of holding the film in place |
Different sizes of film Different image receptor holding devices Bisecting technique |
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What are the main factors to keep the radiographer safe? |
Time Distance Shielding
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What does structural shielding protect the radiographer from? |
from potential scattered radiation |
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How thick does drywall have to be How thick does steel have to be How thick does lead have to be |
2 1/2 to 3 inches 3/16 1 mm
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How far away should a radiographer stand if there is no structural shielding |
6 feet from the head of the patient |
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What Position should the radiographer be at when generating an x-ray if the patient is sitting upright |
45 degree angle |
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What position should the radiographer be at when generating an x-ray if the patient is in the supine position |
135 to 180 degrees |
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What is area monitoring |
On-site survey to measure the output of the dental x-ray unit. |
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What are area monitoring used for? |
Check for possible high level radiation areas in an operatory
To determine if any radiation is traveling through the walls |
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What is personal monitoring |
Requires oral health care professionals to wear a radiation monitoring device. |
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What is the name of the personal monitoring device |
Dosimeter |
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What are examples of Dosimeters |
Film Badge TLD OSL monitor DIS Monitor |
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What are the radiation methods to keep the radiographer safe from radiation |
Follow patient protective measures Do not contact the tubehead Avoid retakes Do not hold the image receptor Use protective barriers Use leaded protective clothing when necessary Remain 6 feet away and at an 45 degree angle from the exiting primary beam Use Radiation MOnitoring
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What is the Film badge
How is it determined |
Radiosensitive Film in a plastic metal holder lined with filters of different materials with varying materials
Reading the processed film electronically |
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TLD |
Contains crystals, absorb radiation, Crystals are heated after being exposed |
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OSL |
Absorbs radiation Crystals release energy during optical stimulation instead of heat |
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DIS
How is it determined |
Uses a miniature ion chamber to absorb radiation
Digital processing |
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Maximum permissible dose |
as the dose equivalent of ionizing radiation that is not expected to cause detectable body damage at any time in their lifetime |
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How much radiation is the maxium permissible dose for radiation workers?
Besides anybody under the age of 18 or pregnant women? |
50 mSv or 5 Rems per year
5 mSv per year |
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Filtration |
The absorption of long wavelength, less penetrating x-rays from the x-ray beam through a passage through a sheet of metal called a filter |
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Optimum film processing is using time and temperature techniques adequately in an equipped dark room TRUE OR FALSE |
TRUE |
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What is the Maximum permissible Dose for the general public |
5 mSV |