Lec 4 Patient Protection, Personnel Protection Flashcards
What are the 3 guiding principles in implementing radiation protection?
- Justification
- Optimization
- Dose limitation
The dentist should identify situations where the benefit to a patient from the diagnostic exposure likely exceeds the risk of harm.
What principle?
Justification
No practice shall be adopted unless its introduction produces a ____________?
Positive net benefit
Dentists should use every reasonable means to reduce unnecessary exposure to their patients, their staff, and themselves.
What principle?
Optimization
What does ALARA stands for?
As Low As Reasonably Achievable
ALARA holds that exposures to ionizing radiation should be kept as low as reasonably achievable, with economic and social factors being taken into account.
What principle?
Optimization
Use Good Clinical Judgment and Apply Evidence-Based Imaging Guidelines
- Make radiographs when they are likely to contribute to __________ and _______________.
- Use _____________ to assist in determining type and frequency of radiographic examinations.
- Diagnosis and treatment planning
- Selection criteria
Use Best Practices in Radiographic Imaging:
- Optimize your exposure settings to the patient’s ____ and _______ to be imaged.
Intraoral radiography
- Use _____ speed film or digital sensors
- Use ________ to support film or digital sensors
- Use __________ collimation
- Make exposures with ______ kVp
- Use _____ collars
Panoramic radiography
- Use ______________ for film imaging or use digital systems.
Cephalometric radiography
- Use a ___________, if it will not obstruct anatomic landmarks for cephalometry.
Cone beam computed tomography (CBCT)
- ________ the field of view to cover the region of interest.
Film-based imaging
- Use ____________________ rather than “sight” processing, or use an automatic processor.
- size and anatomic area
intraoral:
- E/F speed film
- holders
- rectangular
- 60-70 kVp
- thyroid collars
panoramic:
- rare-earth screens
ceph:
- thyroid collar
cbct:
- restrict
film-based imaging
- time-temperature processing
Use Best Practices in Personnel Protection:
- Stand behind a __________ or at least __ feet (__m) away from patient and away from the x-ray machine when making exposure.
- For handheld devices, ensure the _______________ is in place.
- protective barrier
- 6 feet (2m)
- protective backscatter shield
Provides dose limits for occupational and public exposures to ensure that no individuals are exposed to unacceptably high doses.
What principle?
Dose limitation
The dose equivalent to individuals shall not exceed the limits recommended by the ______ (limitation). This principle applies to dentists and their staff who are exposed occupationally but not to patients because there are no dose limits for individuals exposed for________ purposes.
- ICRP
- diagnostic
Good radiologic practice includes use of the ______ image receptor compatible with the diagnostic task (__-speed film or _____) (ADA 2012).
fastest image receptor;
F-speed/digital
TRUE OR FALSE
Fast films are effective for exposure reduction.
True
__________ intensifying screens are recommended… combined with high-speed film of ______ or greater (ADA 2006).
- Rare-earth
- 400
What are the the two rare-earth elements used in extraoral radiography? (2)
Gadolinium, lanthanum
Use of long source-to-skin distances of ____ cm, rather than short distances of 20 cm, decreases exposure by 10 to 25 percent.
40cm
Distances between ___ cm and ___ cm are appropriate, but the ______ distances are optimal (ADA 2006).
- 20 and 40cm
- longer distances
Since a ___________ collimator decreases the radiation dose by up to fivefold as compared with a circular one, radiographic equipment should provide _______ collimation for exposure of periapical and bitewing radiographs (ADA 2012).
rectangular
The purpose of this is to preferentially remove these low-energy xray photons from the x-ray beam
Filtration
____ mm of aluminum for a machine operating at 50 to 70 kVp and ____ mm of aluminum for machines operating at higher voltages.
- 1.5mm
- 2.5mm
The ______ gland is more susceptible to radiation exposure during dental radiographic exams given its anatomic position, particularly in ______.
- thyroid
- children
TRUE OR FALSE
Protective thyroid collars should be used whenever possible.
TRUE
These equipment align the film precisely with the collimated beam are recommended for periapical and bitewing radiographs (ADA 2006).
Film holders
- Their use results in a significant reduction in unacceptable images and thus avoidable retakes.
- Used to control the position and alignment of the film or sensor with respect to the teeth and jaws.
Film and sensor holders
The optimal operating potential of dental x-ray units is between ___________ kVp
60-70 kVp
Kilovoltage (kVp) influences image contrast and patient dose.
- At lower kVp, the image contrast is _______, which could potentially enhance diagnosis.
- At higher kVp, the patient radiation dose is ______.
- increased
- decreased
This is controlled by the quantity of x-rays produced, which is best controlled by the combination of milliamperage and exposure time, termed milliampere-seconds.
Image density
Milli-ampere seconds should be set at the ______ (highest/lowest?) mA setting.
highest
Interpreting images:
- ______ room with light transmitted through the films;
- All ________ light should be eliminated.
- In addition, radiographs should be studied with the aid of a ____________ to detect even the smallest change in image density.
- semi-darkened room
- extraneous light
- magnifying glass
When shielding is not possible, the operator should stand at least ___ meters from the tube head and ____ of the path of the primary beam
- 2 meters
- out of the path
Barrier should have a _________ to allow visual and verbal contact with the patient during exposure.
- leaded window
Position-and-distance rule:
Operator should stand at least _________ from the patient at an angle of ____ to ____ degrees to the central ray of the x-ray beam.
- 6 ft (2m)
- 90-135 degrees
TRUE OR FALSE:
Operators should hold films or sensors in place.
FALSE
Operators should NEVER hold films or sensors in place.
TRUE OR FALSE
Parent or Individual responsible for patient should be the one to hold film in place while wearing a protective apron.
TRUE
TRUE OR FALSE
Battery operated devices designed to be held by the operator.
TRUE
- Device must be held in a ________ position, oriented _______ to the operator
- If angling the device, it is necessary to ____ the patient’s head as well as this can expose the operator to scatter radiation.
- horizontal position; perpendicular
- angle
To minimize exposure to the operator, a _____________ is incorporated into the device at the end of the collimator ring and provides a zone where scattered radiation is negligible.
backscatter shield
- The ADA recommends that workers who may receive an annual dose _________ should wear personal ________ to monitor their exposure levels.
- ______ dental personnel operating x-ray equipment should use personal dosimeters, regardless of anticipated exposure levels (ADA 2012).
- greater than 1 mSv
- dosimeters
- pregnant
Annual effective dose for Occupational exposure (by NCRP)?
50 mSv / year
Annual effective dose for Public exposure?
1 mSv
- ICRP-established dose limit for occupationally exposed individuals is _______ mSv of whole-body radiation exposure per year.
- ______ average dose for individuals occupationally exposed in the operation of dental x-ray equipment.
- 20 mSv
- 0.2 mSv
TRUE OR FALSE:
No limits on the exposure a patient can receive diagnostic examinations, interventional procedures, or radiation therapy.
TRUE.
This is because these exposures are made intentionally for the direct benefit of the recipient.
Is defined as a program for periodic assessment of the performance of all parts of the radiologic procedure.
Quality assurance
