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05 1Rad Radiation Safety for Patients and Operators

Terms in this set (110)

Which type of radiation is the most penetrating beam produced at the target of the anode?
Secondary
Which is the description for the acronym ALARA concept?
As Low As Reasonably Achievable
Which of the following is the least sensitive to radiation exposure?
Nerve cells
Your adult recall patient has no clinical caries and is not at increased risk for caries. He had bitewing images taken one year ago. When should you take bitewing images on your patient.
24-36 months from his last bitewing images
Which statement is correct regarding filtration of the x-ray tubehead?
It results in a more penetrating, useful beam.
Inherent filtration in the dental x-ray tubehead: _________________________.
includes filtration that takes place when the primary beam passes through the glass window of the x-ray tube, the insulating oil, and the tubehead seal
Which of the following is true about the exposure of radiation on the body? According to the direct theory of radiation, what happens to your patient as a result of exposure to x-ray photons?
Damage occurs as a result of ionizing radiation hitting critical areas.
The coin test is used to determine__________
safety light adequacy.
Which of the following steps should be followed when exposing a panoramic image?
Instruct the patient to close the lips on the bite block and to swallow once and then place the tongue against the roof of the mouth to maintain that position during exposure.
Which can occur if there is radiation injury during tooth development?
Tooth bud destruction
From which of the following metals is the filter made?
Aluminum
What exposure control selection(s) controls the quality of the x-ray beam?
Kilovoltage
Which of these is not a reason to understand ionizing radiation?
Ionizing radiation is not harmful.
The kV setting controls which of the following?
Penetrating power of x-ray energy.
X-rays are produced at the
positive anode.
Which cells of the body are least susceptible to x-ray?
Muscle
What is occurring inside the x-ray tubehead when you increase the kilovoltage setting on the exposure control panel?
The penetrating power of the x-ray beam increases.
How far away from the x-ray beam must you stand when exposing dental images on your patient in order to be protected from the primary beam?
6 feet
Which type of receptor would produce the smallest patient dose of radiation?
Digital sensor
You have added an extension to your PID. The length of the PID is changing from 16 to 12 inches. How does this affect the intensity of the x-ray beam? What adjustment will you need to make to keep the density of your images consistent?
The resultant beam will be two times as intense. You will need to decrease the exposure time.
Your patient is a pretty large man, on the obese side. What adjustment would you make, if any, to the control panel when exposing dental images?
Increase the exposure time, kV, and mA.
Which of the following devices would be used to aid in positioning the PID in relation to the tooth and image receptor?
Beam alignment device
The sharpness of a dental image is influenced by all of the following factors except one. Which is the EXCEPTION?
Target-to-image receptor distance
When x-ray exposure time is increased, there is __________density of the dental image.
increased
Which of the following is an acceptable emission from the tubehead?
Primary radiation
Which is the metal disk with a small opening located inside the position indicator device in the path of the x-ray beam?
Lead collimator
What role do dental images play in comprehensive patient care?
Vital component
What is the term to describe the time between radiation exposure and the appearance of the first clinical signs?
Latent period
The sensitivity of a film or film ___________ determines how much radiation and how much exposure time are necessary to produce an image on a film.
speed
The _______ is an extension of the x-ray tubehead and is used to direct the x-ray beam.
PID (position-indicating device)
Divergence of the x-ray beam is reduced by using ____________.
the paralleling technique
What is the purpose of a collimator?
Restricts the size and shape of the beam
Which of the following errors will occur when the PID is positioned incorrectly?
Overlap
Your 13 year old patient has been coming regularly to the dental office for the last 6 years. The last set of dental images were taken a year ago. She has no visible decay, is not at risk for caries, and there are no restorations, and closed contacts. When should you take dental images?
18-36 months from her last bitewing images
What is a practical alternative for operator safety in the absence of a lead wall?
The operator stands at a 90-degree angle to the tubehead.
Commercially available barrier envelopes are used to
minimize contamination in the darkroom.
Which is the purpose of the lead foil in the film packets?
To stop the backscatter radiation
Milliamperage controls heating of the __________
cathode.
An increase in exposure time will result in an image that is
more dense.
All of the following relate to operator safety except ________________.
using the paralleling technique
Which of the following position indicating devices exposes a patient to more radiation?
Conical
An increase in the kV setting will result in a(n)
decrease in contrast.
After which year did all newly manufactured dental x-rays machines have to meet federal regulations?
1974
What will occur if a lead apron is folded instead of hung?
It will crack and become ineffective.
What is the single best way to protect a patient from unnecessary radiation exposure?
Use of digital receptor
Which type of radiation byproduct is not associated with patient interaction?
Tertiary
Which source produces the most annual radiation exposure to persons in the United States?
Radon
The amount of radiation required to produce an image of standard density refers especially to film _______________
speed.
What can a radiographer wear to measure the daily amount of radiation exposure?
Dosimeter badge
Which of the following refers to operator protection during dental imaging procedures?
Avoid the primary beam
Which are the majority of x-rays produced by dental x-ray machines?
Bremsstrahlung radiation
Which body tissue listed is the most sensitive to radiation exposure?
Bone marrow
The angulation of the central ray when using the bisection angle technique is __________ degrees to the imaginary bisector.
90
What is the term to describe the point in radiation exposure when cell death occurs?
Period of injury
Which of the following prevents further penetration of the primary beam?
Lead foil
Equipment filtration is comprised of which of the following? 1. Inherent filtration 2. Added filtration 3. Total filtration
1, 2, 3
Which cells are affected when radiation exposure produces mutations to future generations?
Genetic
Which is the primary example of a patient protection technique used before x-ray exposure?
Proper prescribing of dental images
Where should you stand in relation to the primary beam when taking dental images on your patient in order to be protected from the primary bean?
Perpendicular
What is the maximum permissible dose a dental radiographer is allowed to accumulate in a year?
5.0 rem
What is the size of the x-ray beam produced by a circular collimator as it exits the PID?
2.75 inches
Which cell would be considered to have high radiation sensitivity?
Small lymphocyte
The purpose of the intensifying screen in a panoramic cassette is to reduce
radiation exposure.
Which controls the quantity of an x-ray beam?
Milliamperes
The overall blackness or darkness of a film is __________.
density
If your patient refuses to have images and signs a waiver of liability
it becomes invalid when there is personal injury.
What dental imaging geometric characteristic is also referred to as "detail" or "resolution"?
Sharpness
Your last patient was an average size male. You next patient is a slender 12 year old girl. What adjustment would you make, if any to the control panel when exposing dental images?
Decrease the exposure time, leave the kV, and the mA the same
What is the maximum permissible dose of radiation exposure that you as a dental professional are allowed to be exposed to in a year?
0.05 Sv/yr
What is the purpose of including a lead collimator inside the dental tubehead?
To restrict the size and shape of the x-ray beam
Which statement regarding the lead apron is correct?
The lead apron is recommended for intraoral images.
Which form of radiation is found in the environment and includes cosmic and terrestrial radiation?
Background
Under which situation is it not necessary for the patient to wear a thyroid collar?
During extraoral exposures.
What is the purpose of the receptor-holding device?
It stabilizes the receptor position in the mouth and reduces the chance for movement.
The x-ray beam is restricted to a diameter of no more than __________ at the surface of the skin.
7 cm
Your adult recall patient has had occlusal or interproximal caries the last four biannual visits. He had restorations placed following each visit. He has visible caries today on teeth #30 and #19. He had bitewing images taken at the last visit. When should you take bitewing images on your patient. Your patient has insurance.
At this appointment
Which statements are true about the lead apron?
Both B and C are true.
Elongation and foreshortening are examples of what radiographic characteristic?
Distortion
Which of the following changes describes the development of cataracts in a person who has been exposed to excessive radiation?
Somatic
In addition to the patient's name, what other information should be placed on the film mount?
Date of exposure
Which statement regarding exposing dental images is correct?
Each patient should be evaluated for need.
If you increased exposure time and left the other exposure factors the same, what impact would this have on your dental image?
The image would be darker because the density increases.
If you decreased the mA and left the other exposure factors the same, what impact would this have on your dental image?
The image would be lighter because the density decreases.
Which of the following is not a patient protection measure that can be used before any x-radiation exposure occurs?
Use of a lead apron
Which of the following is important when exposing dental x-rays on a patient?
Technique, maintenance, and education
When a pregnant patient expresses concern about the need for dental images, which statement is most appropriate?
The doctor has ordered only the x-ray that is essential for your treatment today.
What is the function of intensifying screens used in extraoral radiography?
To decrease the exposure to radiation for the patient.
Which of the following would actually increase exposure time to a patient?
Decreasing kV by 15%
Which is located in the PID and removes the longer-nonpenetrating wavelength x-rays from the beam?
Aluminum filter
Which of the following applies to producing dental images on pregnant patients?
Guidelines are designed to protect the patient; no alterations need to be applied.
Your office has just started using digital radiography, you had been using analog film. Exposure time will be
decreased.
You notice that the roots of your maxillary anterior images are consistently too long and seem out of proportion. What is the error and how should you correct it?
Elongation, the receptor needs to be parallel to the teeth and the x-ray beam needs to be perpendicular to both.
You have added an extension to your PID. The length of the PID is changing from 8 to 16 inches. How does this affect the intensity of the x-ray beam? What adjustment will you need to make to keep the density of your images consistent?
The resultant beam will be one-quarter as intense. You will need to increase the exposure time.
You noticed that your patient moved just as you pressed the exposure button. What affect will that have on your dental image?
Alteration in image sharpness
Which of the following is the acronym for the principle that governs exposure to radiation?
ALARA
What type of contrast will your image have if you used the 90 kV setting?
Low contrast with many shades of gray.
Which of the following exposure factors does not control the dentistry of an image?
Collimator
An important way for the operator to avoid primary beam exposure is to:
Position himself or herself at a 90 to 135 degree angle to the primary beam
Which of the following represents the maximum permissible dose (MPD) for the general public?
0.1 rem per year
Which of the following is true about the exposure of radiation on the body?
The indirect theory of radiation suggests that ionizing radiation creates the formation of free radicles.
Which is the person responsible for prescribing dental radiographs?
Dentist
Which term best describes the concept of radiation protection as it pertains to technique, amount, and quality?
ALARA
Which of the following provides the most protection for the patient?
Pixels
You suspect your patient has periodontal disease. Which type of contrast would be the best to use when looking for periodontal disease?
Low contrast; many shades of gray
Your 5-year-old patient has been coming regularly to the dental office for the last 2 years. The last set of dental images were taken 6 months ago. He has occlusal decay on #A, B, I, and J and his teeth are in tight contact. Last time he was in he had restorations placed on teeth #K and #L. When should you next take dental images?
Today's appointment
What effect will occur by increasing the kilovoltage setting on the exposure control panel?
It increases the penetrating power of the x-ray beam.
Which of the following is a true statement regarding pregnant patients and exposure to radiation?
Lead aprons prevent exposure to the fetus.
Which of the following is an accurate statement about safe operating procedures?
All dental staff members should wear dosimeters.
Which cells are affected when radiation exposure produces tumors and illnesses?
Somatic
Which is the most sensitive tissue or organ to radiation?
Reproductive cells
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