DENT 1050 Chapter 5 Flashcards
TRUE or FALSE
Every patient should be evaluated individually for dental radiographs.
TRUE
TRUE or FALSE
The 8-inch PID is more effective than the 16-inch PID in reducing radiation exposure of the patient.
FALSE
TRUE or FALSE
Pointed cones should not be used because of increased scatter radiation.
TRUE
TRUE or FALSE
The thyroid collar must be worn for both intraoral and extraoral exposures.
FALSE
TRUE or FALSE
If necessary, the dental radiographer may hold a receptor in the patient’s mouth to ensure a diagnostic image.
FALSE
Which of the following describes the use of a filter in a dental x-ray tubehead?
a. A filter reduces the size and shape of the beam.
b. A filter removes low-energy x-rays.
c. A filter removes the dose of radiation to the thyroid gland
d. A filter decreases the mean energy of the beam
b. A filter removes low-energy x-rays.
Which of the following is not a component of inherent filtration?
a. oil
b. unleaded glass window
c. a leaded cone
d. tubehead seal
c. a leaded cone
Which of the following is the most effective method of reducing patient exposure to radiation?
a. lead apron
b. fast films
c. round PID
d. film-holding devices
b. fast films
Which of the following position-indicating devices is most effective in reducing patient exposure?
a. conical PID
b. rectangular PID
c. round PID
d. all are equally effective in reducing patient exposure
b. rectangular PID
Which of the following devices restricts the size and shape of the x-ray beam?
a. filter
b. collimator
c. barrier
d. film badge
b. collimator
Which of the following is used as a collimator?
a. lead plate
b. aluminum plate
c. copper plate
d. all of the above
a. lead plate
Which of the following describes the function of filtration?
a. increases scatter radiation
b. increases divergent rays
c. increases long wavelengths
d. reduces low-energy waves
d. reduces low-energy wavesa
Which of the following is the recommended size of the beam at the patient’s face?
a. 2.75 inches
b. 3.25 inches
c. 3.50 inches
d. 4.00 inches
a. 2.75 inches
Which of the following terms describes the dose of radiation that the body can endure with little or no chance of injury?
a. radiation limit
b. maximum permissible dose
c. occupationally exposed dose
d. ALARA
b. maximum permissible dose
Which of the following is true of radiation monitoring badges?
a. badges should be worn when the radiographer is undergoing x-ray exposure.
b. badges can be shared between employees.
c. badges should be worn at waist level when exposing x-ray receptors
d. All of the above are true.
c. badges should be worn at waist level when exposing x-ray receptors
FILL IN THE BLANK
Provide the requirements for proper filtration:
a. Machines operating at 70 kVp or lower require _____________ mm aluminum.
b. Machines operating above 70 kVp require _____________ mm aluminum.
a. Machines operating at 70 kVp or lower require __MINIMUM TOTAL OF 1.55__ mm aluminum.
b. Machines operating above 70 kVp require __MINIMUM TOTAL OF 2.5__ mm aluminum.
FILL IN THE BLANK
State the angle that the dental radiographer should stand to the primary beam: ___________ degrees.
90-135
FILL IN THE BLANK
State the formula for maximum accumulated dose: __________________________________________.
MAD = (N - 18) x 5 rems/year
MAD = (N - 18) x 0.05 Sv/year
FILL IN THE BLANK
State the maximum permissible dose for occupationally exposed persons: _________rems/year ( _________Sv/year)
5.0 rems/year (0.05 Sv/year)
ALARA concept
As Low As Reasonably Achievable; every possible method of reducing exposure to radiation should be employed to minimize risk
Beam alignment device
helps stabilize the receptor in the mouth and reduces the chances of movement
Collimation
used to restrict the size and shape of the x-ray beam and to reduce patient exposure
Collimator
lead plate with a hole in the middle, fitted directly over the opening of the machine housing where the x-ray beam exits the tubehead
Film, D-speed
aka Ultra-Speed
Film, E-speed
aka Ektaspeed; came before F-speed
Film, F-speed
aka InSight; fastest intraoral film available; provides an additional 20% reduction in exposure over E-speed and 60% reduction in exposure over D-speed
Film, fast
the most effective method of reducing a patient’s exposure to x-radiation
Filtration
filtering to limit the amount of x-radiation a dental patient receives
Filtration, added
refers to the placement of aluminum discs in the path of the x-ray beam between the collimator and the tubehead seal in the dental x-ray machine
Filtration, inherent
takes place when the primary beam passes through the glass window of the x-ray tube, the insulating oil, and the tubehead seal
Filtration, total
inherent plus added filtration; state and federally regulated; machines at or below 70 kVp require minimum total of 1.55 mm aluminum filtration and machines above 70 kVp require a minimum total of 2.5 mm aluminum filtration
Lead apron
a flexible shield placed over the patient’s chest and lap to protect the reproductive and blood-forming tissues from scatter radiation
Maximum accumulated dose (MAD)
determined by a formula based on the worker’s age;
MAD = (N - 18) X 5 rems/year
MAD = (N - 18) X 0.05 Sv/year
Maximum permissible dose (MPD)
the maximum dose equivalent that a body is permitted to receive within a specific period; that which the body can endure with little or no injury
Position-indicating device (PID)
aka the CONE; appear as an extension of the x-ray tubehead and is used to direct the x-ray beam; three types: conical, rectangular, and round
Protective barrier
adequate shielding of x-radiation; absorb the primary beam thus protecting the operator from primary and scatter radiation
Radiation monitoring badge
personnel-monitoring device that measures the amount of x-radiation that reaches the body of the dental radiographer
Radiation, leakage
any radiation other than the primary beam that is emitted from the dental tubehead
Thyroid collar
a flexible lead shield that is placed securely around the patient’s neck to protect the thyroid gland from scatter radiation
kVp
kilovoltage peak, used as a measurement in dental x-ray machines
