Radiation Protection Important Notes:
- Lead aprons and collars
Advantages:- Lead aprons reduce 94% if scattered radiation to the gonads
- Protects gonads from radiation exposure
- Thyroid collars reduce the exposure of this gland by 92%
- Position distance rule
- The operator should stand at least 6 feet from the patient, at an angle of 90 degrees to 135 degrees to the central ray beam when the exposure is made.
- This called as Position – – distance rule.
- E speed films
Advantages:- The most effective method of reducing patient dose
- The risk is reduced by a factor of 2
- Contains large tubular grains which increase the speed
- The exposure time is 0.2 sec compared to regular film which is 9 sec
- Disadvantage
- Decreases image sharpness.
Radiation Protection Long Essays
Question 1. Enumerate hazards of radiation. Describe protective measures for the patient and the operator against it.
Answer.
Hazards Of Radiation:
- Biologic changes:
- Changes in DNA:
- Change in base
- Disruption of hydrogen bonds
- Breakage of DNA strands
- Cross-linking of DNA strands
- Proteins:
- Denaturation of proteins
- Changes in DNA:
- Cellular changes
- Nuclear changes
- Chromosome aberration
- Cytoplasmic changes
- Tissue changes:
- Non stochastic Effects
- Stochastic Effects
Read And Learn More: Oral Radiology Question and Answers
Radiation Protection:
- Radiation protection for the patient:
- Patient selection:
- Professional judgment should be used to select the patient for an X-ray examination
- Choice of equipment:
- Image receptor – to reduce the exposure time
- A focal spot to film distance
- With the increase in distance, the exposure time reduces
- Collimation – it reduces the size of the X-ray beam
- Filtration – to remove low-energy photons
- Use of lead aprons and collars
- It minimizes unnecessary radiation exposure
- Choice of intraoral technique:
- Parallel radiographic technique causes less exposure, hence used
- X-ray equipment:
- Make use of:
- High kVp
- Increased made
- Reduced exposure time
- Patient selection:
- Processing of film:
- Make use of the proper method of processing
- Avoid repetition of X-ray
- Interpretation of image:
- Properly interpreted the X-ray in a semi-darkened room
- Note down all the necessary details
- Processing of film:
- Radiation protection to the operator:
- The following measures must be carried out by the operator to avoid unnecessary radiation exposure
- During exposure, the operator must leave the room/stand behind a suitable barrier
- The operating room should meet the minimum shielding requirements
- The position of the operator during exposure should be 6 feet away from the source
- At an angle of 90 – 135°
- Avoid holding the film intraorally
- Avoid stabilizing the tube during exposure
- Use a lead apron in the absence of a barrier
- Avoid the use of fluorescence mirror during exposure
- Make use of filtration
- Carry out personal radiation monitoring periodically
Question 2. Discuss various measures for radiation protection.
Answer.
- Radiation protection for the patient:
- Patient selection:
- Professional judgment should be used to select the patient for an X-ray examination
- Choice of equipment:
- Image receptor – to reduce the exposure time
- A focal spot to film distance
- With the increase in distance, the exposure time reduces
- Collimation – it reduces the size of the X-ray beam
- Filtration – to remove low-energy photons
- Use of lead aprons and collars
- It minimizes unnecessary radiation exposure
- Choice of intraoral technique:
- Parallel radiographic technique causes less exposure, hence used
- X-ray equipment:
- Make use of:
- High kVp
- Increased mA
- Reduced exposure time
- Make use of:
- Processing of film:
- Make use of the proper method of processing
- Avoid repetition of X-ray
- Interpretation of image:
- Properly interpret the X-ray in a semi-darkened room
- Note down all the necessary details
- Patient selection:
- Radiation protection to the operator:
- The following measures must be carried out by the operator to avoid unnecessary radiation exposure
- During exposure, operator must leave the room/stand behind a suitable barrier
- The operating room should meet the minimum shielding requirements
- The position of the operator during exposure should be 6 feet away from the source
- At an angle of 90 – 135°
- Avoid holding the film intraorally
- Avoid stabilizing the tube during exposure
- Use a lead apron in the absence of a barrier
- Avoid the use of fluorescence mirror during exposure
- Make use of filtration
- Carry out personal radiation monitoring periodically
- Radiation protection to the public:
- X-ray room must be
- Lined with lead
- Constructed with gypsum
- Painted with barium
Radiation Protection Short Essays
Question 1. Radiation protection for patients.
Answer.
- Patient selection:
- Professiojudgmentment should be used to select the patient for an X-ray examination
- Choice of equipment:
- Image receptor – to reduce the exposure time
- A focal spot to film distance
- With the increase in distance, the exposure time reduces
- Collimation – it reduces the size of the X-ray beam
- Filtration – to remove low-energy photons
- Use of lead aprons and collars
- It minimizes unnecessary radiation exposure
- Choice of intraoral technique:
- Parallel radiographic technique causes less exposure, hence used
- X-ray equipment:
- Make use of:
- High kVp
- Increased made
- Reduced exposure time
- Processing of film:
- Make use of the proper method of processing
- Avoid repetition of X-ray
- Interpretation of image:
- Properly interpret the X-ray in a semi-darkened room
Note down all the necessary details
- Properly interpret the X-ray in a semi-darkened room
Question 2. Radiation protection for the operator.
Answer.
Radiation protection for the operator
- The following measures must be carried out by the operator to avoid unnecessary radiation exposure
- During exposure, the operator must leave the room/stand behind a suitable barrier
- The operating room should meet the minimum shielding requirements
- The position of the operator during exposure should be 6 feet away from the source
- At an angle of 90 – 135°
- Avoid holding the film intraorally
- Avoid stabilizing the tube during exposure
- Use a lead apron in the absence of a barrier
- Avoid the use of fluorescence mirror during exposure
- Make use of filtration
- Carry out personal radiation monitoring periodically
Question 3. Image receptors.
Answer.
- E-speed films:
- Used to reduce the exposure time
- Double-sided emulsion:
- Reduces exposure
- Double film packets:
- Reduces the radiation needed
- Xeroradiography
- Good edge enhancement
- Good image quality
- Reduces exposure
- Intensifying screens:
- Used in extraoral radiography
- Contains phosphors that fluorescence on exposure to the x-ray beam
- The intensity of it is directly proportional to the intensity of the x-ray beam
Question 4. Intensifying Screens.
Answer.
Intensifying Screens
These are used with all extraoral radiographs
Intensifying Screens Types:
- Blue emitting
- Green emitting
Intensifying Screens Mechanism:
Intensifying Screens Composition:
- Base
- Reflecting layer
- Phosphor layer
- Protective coat
Radiation Protection Short Answers
Question 1. ALARA principle.
Answer.
ALARA principle
- It is the abbreviation of “As Low As Reasonably Achievable”
- It suggests that no matter how small the dose is, the stochastic effect may result.
- Following are the guidelines of the ALARA principle
- For radiation workers
- For occupational exposure – 50 mSv in 1 year
- For reproductive age – 10 mSv in 1 year
- For general public
- Annual effective dose – 1 mSv
Question 2. Dosimetry
Answer.
Dosimetry
- It is the measurement of the quantity of the radiation exposure or the amount of the energy absorbed per unit mass at an interest site
Dosimetry Techniques:
- Ionization chamber:
- Plates with opposite charges are connected to an electrometer
- These are separated by a standard volume of air
- The X-ray beam is passed through the air
- This leads to the generation of positive and negative ions
- These are attracted to the plates
- The potential difference between the plates is measured
- Film badges:
- A worn film with metallic badges is used
- It is processed along with the films of known amount of exposure
- Next, the degree of darkening is measured and compared
- Thermoluminescent dosimeters:
- Crystals like lithium fluoride are used
- These crystals absorb radiation energy:
- It results in the release of visible light
- This is proportional to the absorbed energy
Question 3. Leakage radiation/Stray radiation.
Answer.
Leakage radiation/Stray radiation
- It is defined as radiation emitted by any other part of the X-ray tube other than the focal spot
- It can be prevented by
- Avoid holding of the tube during exposure
- Check the X-ray machine periodically for leakage
Question 4. Thermoluminescence dosimeter.
Answer.
Thermoluminescence dosimeter
- Crystals like lithium fluoride are used
- These crystals absorb radiation energy
- It results in the release of visible light
- This is proportional to the absorbed energy
Question 5. Position & distance rule.
Answer.
Position & distance rule
- The operator should stand at least 6 feet from the patient, at an angle of 90 – 135° to the central ray beam when the exposure is made.
- This is called the position and distance rule.
Radiation Protection Viva Voce
- The gonadal dose is 1/1000 of exposure to skin
- Dosimetry – Determining the quantity of radiation exposure or does.
- The distance of the safe light from the working area in a dark room is 4 feet