Radiology Safety Flashcards
What does ALARA stand for?
As Low As Reasonably Achievable
Who is the approving authority for radiation worker training in the medical/dental facility?
MRSO
Doubling the distance (between you and the radiation source) decreases the radiation intensity by a factor of…
4
When should an operator stand behind the protective barrier during the entire exposure?
Always!
The shorter exposure time, the less potential exposure for which individuals?
CBCT Operator
Patient
Public
Do you document CBCT retakes?
Yes! Document the reason for the retake on the log in the binder in the CBCT room.
What are examples of Stochastic Effects?
Long Term or Chronic
- Low does (<100 mSv) damage to cells can cause random mutations
- Increased risk of cancer or genetic mutation as dose increases
- Effects may be seen many years or generations later
What are Deterministic Effects?
Short Term or Acute
- High doses (>1 Gy) over a short period
- Damage & cell killing begins with a threshold dose and increases in severity as dose increases
- Effect radiation burns, hair loss, damage to immune system
Exposure to ionizing radiation has many individual risk factors, can you name some?
- Age
- Gender
- Heredity
- Environment
Exposure to ionizing radiation can cause?
- Injury to living tissue (cell killing or cell modification)
- Increase radiation, increase the chance of cancer - which some don’t appear until years after the radiation dose (latency)
The effects on the conceptus depend on…
Time of irradiation relative to conception
Do you DRAPE the protective apron over every dental patient prior to a CBCT exposure?
Yes!
Cover front with torso apron at sitdown CBCT
Cover front/back with apron at upright design CBCT
The adolescent and adult patient requires attention to what 3 factors?
Age, gender, and body size
The referring provider selects what appropriate diagnostic tasks for a CBCT?
- Field of View (FOV)
- Purpose of the Scan
- Volume Size
- Area of Interest (tooth, teeth, jaw, arch, craniofacial)
- Resolution (voxel size)
- kV, mA
- Special Instructions
One can optimize the exposure settings based on what 3 parameters?
- FOV
- Patient Size
- Area of Interest Imaged
By taking a CBCT with a smaller FOV you gain?
High Diagnostic Accuracy
Higher resolution means?
- More Basis Projections
- Small Voxel Size
- Increased mA
- Higher Dose to the Patient
Evaluation of occult root fractures, root apical lesions require higher or lower resolution?
Higher!
Lower resolution means…
- Fewer Basis Projections
- Larger Voxel
- Decreased mA
- Lower Dose to the Patient
A CBCT captured using a lower resolution (larger voxel) is suggested for evaluation of…
- Craniofacial Deformities
- Orthodontic Evals
- Oral Surgery
What is the order of business when using the CBTCT machine?
- Enter/import patient data into computer
- Select a Resolution
- Select Volume Size
- Position Patient
- Dry Run (if needed)
- Preview scan or “Scout”
- Acquire the Scan
- Data Reconstruction
What are 8 uses of a CBCT?
- Orthodontic Growth and Development Evals
- Orthognathic Surgery and Craniofacial Evals
- Dento-Alveolar Impactions
- Trauma
- TMJ Assessments
- Implant Site Assessments
- Endodontic Apical and Occult Root Fracture
- Pathology Adjunct Evaluation
What does a “Dry Run” accomplish?
- No radiation exposure to the patient
2. Demonstrates the arc rotation around the patient
What is a “scout” scan used for?
- Lateral and Posterior-Anterior 2D radiographic snapshots
- Used to align patient in CBCT machine prior to acquiring scan
- The radiation exposure of scout are fractions of a second
- The volume FOV is about 25% smaller than the scout image
- The scout captures appear slightly different for the CBCTs
