Radiation Protection Long and Short Essays

Radiation Protection Important Notes:

  • Lead aprons and collars
    Advantages:

    • Lead aprons reduces 94% if scattered radiation to the gonads
    • Protects gonads from radiation exposure
    • Thyroid collars reduces 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 degree to 135 degree to the central ray beam when the exposure is made.
    • This called as Position – and – distance rule.
  • E speed films
    Advantages:

    • Most effective method of reducing patient dose
    • The risk is reduced by a factor of 2
    • Contains large tubular grains which increases 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 patient and 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
  • Cellular changes
    • Nuclear changes
    • Chromosome aberration
    • Cytoplasmic changes
  • Tissue changes:
    • Non stochastic Effects
    • Stochastic Effects

Radiation Protection:

  • Radiation protection to the patient:
    • Patient selection:
      • Professional judgement should be used to select the patient for X-ray examination
    • Choice of equipment:
      • Image receptor – to reduce the exposure time
      • Focal spot to film distance
      • With 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 the 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

Read And Learn More: Oral Radiology Question and Answers

    • Processing of film:
      • Make use of proper method of processing
      • Avoid repetition of X-ray
    • Interpretation of image:
      • Interprete the X-ray in proper way in a semi-darkened room
      • Note down all the necessary details
  • Radiation protection to the operator:
    • Following measures must be carried out by the operator to avoid unnecessary radiation exposure
    • During exposure operator must leave the room/stand behind suitable barrier
    • Operating room should meeet the minimum shielding requiements
    • Position of the operator during exposure should be 6 feet away from source
    • At an angle of 90 – 135°
    • Avoid holding the film intraorally
    • Avoid stabilizing tube during exposure
    • Use lead apron in absence of barrier
    • Avoid use of fluorescence mirror during exposure
    • Make use of filtration
    • Carry out personal radiation monitoring periodically

Question 2. Discuss various measures at radiation protection.
Answer.

  • Radiation protection to the patient:
    • Patient selection:
      • Professional judgement should be used to select the patient for X-ray examination
    • Choice of equipment:
      • Image receptor – to reduce the exposure time
      • Focal spot to film distance
      • With 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 the 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
    • Processing of film:
      • Make use of proper method of processing
      • Avoid repetition of X-ray
    • Interpretation of image:
      • Interpret the X-ray in proper way in a semi-darkened room
      • Note down all the necessary details
  • Radiation protection to the operator:
    • Following measures must be carried out by the operator to avoid unnecessary radiation exposure
    • During exposure operator must leave the room/stand behind suitable barrier
    • Operating room should meet the minimum shielding requirements
    • Position of the operator during exposure should be 6 feet away from source
    • At an angle of 90 – 135°
    • Avoid holding the film intraorally
    • Avoid stabilizing tube during exposure
    • Use lead apron in absence of barrier
    • Avoid use of fluorescence mirror during exposure
    • Make use of filtration
    • Carry out personal radiation monitoring periodically
  • Radiation protection to public:
    • X-ray room must be
    • Lined with lead
    • Constructed with gypsum
    • Painted with barium

Radiation Protection Short Essays

Question 1. Radiation protection for patient.
Answer.

  • Patient selection:
    • Professional judgement should be used to select the patient for X-ray examination
  • Choice of equipment:
    • Image receptor – to reduce the exposure time
    • Focal spot to film distance
    • With 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 the 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 proper method of processing
    • Avoid repetition of X-ray
  • Interpretation of image:
    • Interprete the X-ray in proper way in a semi-darkened room
      Note down all the necessary details

Question 2. Radiation protection for operator.
Answer.

Radiation protection for operator

  • Following measures must be carried out by the operator to avoid unnecessary radiation exposure
  • During exposure operator must leave the room/stand behind suitable barrier
  • Operating room should meet the minimum shielding requirements
  • Position of the operator during exposure should be 6 feet away from source
  • At an angle of 90 – 135°
  • Avoid holding the film intraorally
  • Avoid stabilizing tube during exposure
  • Use lead apron in absence of barrier
  • Avoid 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 x-ray beam
    • Intensity of it is directly proprotional 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:

Oral Radiology Radiation Protection 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 does is, the stochastic effect may result.
  • Following are the guidelines of 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
    • X-ray beam is passed through the air
    • This leads to generation of positive and negative ions
    • These are attracted to the plates
    • The potential difference between the plates is measured
  • Film badges:
    • Worn film with metallic badges are 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 absorbs 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 absorbs radiation energy
  • It results in the release of visible light
  • This is proportional to the absorbed energy

Oral Radiology Radiation Protection The drawer and heater arrangement in a thermoluminescence dosimeter

Question 5. Position & distance rule.
Answer.

Position & distance rule

  • The operator should stand atleast 6 feet from the patient, at an angle of 90 – 135° to the central ray beam when the exposure is made.
  • This is called position and distance rule.

Radiation Protection Viva Voce

  • Gonadal dose is 1/1000 of exposure at skin
  • Dosimerty – Determining the quantity of radiation exposure or does.
  • The distance of the safe light from working area in dark room is 4 feet

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