Lecture 3 Flashcards
Patient dental image radiation protection occurs when?
Before, during and after exposure
How do we implement patient protection before exposure?
• Proper prescribing of dental images
• Proper equipment: Filtration, Collimation, PID
How do we implement patient protection during exposure?
Lead apron, thyroid collar, image receptor
How do we implement patient protection after exposure?
Proper receptor handling and image retrieval
Effect of x-radiation on living cells and tissues
X-radiation causes biologic changes in living cells and adversely affects all living tissues.
With the use of proper patient protection techniques, the amount of x-radiation received by a dental patient can be____.
minimized
______can minimize the amount of x-radiation that a dental patient receives before X-ray exposure
Proper prescribing of dental images and the use of equipment that complies with state and federal radiation guidelines
What the does the ALARA Principle stand for?
• As Low As Reasonably Achievable
The dentist must prescribe images based on the____.
individual needs of patients
The dental x-ray tubehead must be equipped with ______for patient protection.
appropriate aluminum filters, lead collimator, and position-indicating device
In the x-ray tubehead, aluminum disks are used to_____
filter out the longer-wavelength, low-energy x-rays from the x-ray beam.
Collimation is used to_____
restrict the size and shape of the x-ray beam and to reduce patient exposure.
How does the collimator restrict the size and shape of the X-ray beam to reduce patient exposure?
A collimator, or lead plate has a hole in the middle
Which shape collimator is better to reduce patient exposure?
A rectangular collimator exposes 60% less tissue than a circular collimator
The position-indicating device (PID) appears as______ and is used to_____.
an extension of the x-ray tubehead; direct the x-ray beam
Which is better, an 8 in PID or a 16 in PID?
16 in PID is better because it produces less divergence of the xray beam
PID come in what shape?
Open- ended, lead-lined circular and rectangular PIDs
The use of the thyroid collar is recommended for______.
all intraoral exposures but not recommended with extraoral exposures because it obscures information and results in a nondiagnostic image.
Lead Apron come in different types for____but may or may not come with____
intraoral & extraoral; thyroid collar
Receptor types
• Digital Sensor
• Fast films
Beam Alignment devices help____
stabilize the receptor in the mouth to reduce the chances of movement
One common type of beam alignment device
XCP: “extension cone paralleling”
How can the dental image radiographer/operator protect themselves?
• Shielding
• Distance and Position recommendation
• Radiation Monitoring: Equipment monitoring, Personnel monitoring
Ideally, during exposure, the radiographer should_____
either leave the room or take a position behind a suitable barrier or wall during exposures.
If leaving the room is not possible or if no barrier is available, the radiographer must
adhere to distance and position recommendations. To avoid the primary beam, which travels in a straight line, the dental radiographer must position himself or herself 6 feet away, perpendicular to the primary beam, or at a 90-degree to 135-degree angle to the beam
Primary beam travels____
in a straight line
The dental radiographer should not ____during exposure.
• hold a receptor in place for a patient.
• hold or stabilize the x-ray tubehead.
Dental x-ray machines must be monitored for
leakage radiation.
Leakage radiation is
any radiation, with the exception of the primary beam, that is emitted from the dental tubehead.
For example, if a dental x-ray tubehead has a faulty tubehead seal, leakage radiation results.
Dental x-ray equipment can be monitored for leakage radiation using
a device that can be obtained through the state health department or from the manufacturers of dental x-ray equipment.
The amount of x-radiation that reaches the body of the dental radiographer can be measured through the use of a
personnel-monitoring device known as a radiation monitoring badge
• Also known as dosimeter
• After the dental radiographer has worn the badge for a specified interval (e.g., 1 month), the badge is returned to the service company.
What is the Maximum Permissible Dose (MPD)?
The maximum dose equivalent that a body is permitted to receive within a specific period.
What does the MPD represent?
The maximum dose of radiation that the body can endure with little or no injury.
Who defines the MPD?
Defined by the National Council on Radiation Protection and Measurements (NCRP).