part 2

• Most clinical diagnostic imaging personnel must be

  monitored; however, it usually is not necessary to

  monitor diagnostic radiology secretaries and file

  clerks
• It usually is not necessary to monitor operating room

  personnel, except those routinely involved in

  cystoscopy and C-arm fluoroscopy
• occupational radiation monitor - simply measures

  the quantity of radiation to which the monitor was

  exposed
• occupational radiation monitor - is an indicator of exposure to the wearer and offers no protection against radiation exposure
• three types of personnel monitors are used in diagnostic

  radiology:

  • film badges,
  • thermoluminescence dosimeters
  • optically stimulated luminescence dosimeters
• Film badges - came into general

  use during the 1940s and have

  been used widely in diagnostic

  radiology ever since
• Film badges - are specially designed devices in which a film similar to dental radiographic film is sandwiched between metal filters inside a plastic holder
• The film incorporated into a film badge is a special radiation

  dosimetry film that is particularly sensitive to x-rays
• The optical density on the exposed and processed film is related

  to the exposure received by the film badge
• Film badges must be worn with the appropriate side to the front
• The metal filters, along with the window in the plastic film

  holder, allow estimation of the x-ray energy
• The usual filters are made of aluminum and copper
• Radiation that had entered through the back of the film

  badge normally would indicate that the person wearing the

  badge received considerably HIGHER exposure than

  indicated, because the x-rays would have penetrated

  through the body before interacting with the film badge. True or False?

  true
• Advantages of film badges:

  • Inexpensive
  • Easy to handle
  • Easy to process
  • Reasonably accurate
• Disadvantages of film badges:

  • Cannot be reused
  • Cannot be worn for longer than 1 month because of possible fogging caused by temperature and humidity
  • Usually, exposures less than 100 μGya are not measured
• Film badge monitors - should never be left in an enclosed car or other area where excessive temperatures may occur
• The fogging produced by elevated temperature and humidity results in a falsely high evaluation of radiation exposure
• Thermoluminescence dosimeters- These are used for area and

  environmental radiation monitoring, and especially for occupational radiation monitoring
• The sensitive material of the thermoluminescence dosimeter (TLD) monitor is lithium fluoride in crystalline form, either as a powder or more often as a small chip approximately 3 mm square and 1 mm thick
• When exposed to x-rays, the TLD absorbs energy and stores it in the form of excited electrons in the crystalline lattice
• The intensity of visible light is measured with a photomultiplier tube or photodiode and is proportional to the radiation dose received by the crystal.
• Advantages of TLDs over film badge:

  • It is more sensitive (can measure exposure as low as 50 μGya)
  • more accurate
  • Does not suffer from loss of information after it is exposed to excessive heat or humidity
  • can be worn for intervals up to 1 year
• The primary disadvantage of TLD personnel monitoring is cost
• Optically stimulated luminescence (OSL) dosimeters are worn and handled just as film badges and TLDs are, and they are approximately the same size. TRUE or FALSE?

  TRUE
• OSL dosimeters have one advantage over TLDs. They are

  more sensitive, measuring as low as 10 μGy
• Many radiologic technologists wear their personnel monitors in front at waist or chest level because it is convenient to clip the badge over a belt or a shirt pocket
• If the radiologic technologist participates in fluoroscopy, the occupational radiation monitor should be positioned on the collar above the protective apron
• It has been shown that during fluoroscopy, when a protective apron is worn, exposure to the collar region is approximately 20 times greater than that to the trunk of the body beneath the protective apron
• So, if the occupational radiation monitor is worn beneath the protective apron, it will record a falsely low exposure and will not indicate what could be excessive exposure to unprotected body parts
• During pregnancy and with extremity monitoring, it may be advisable to wear more than one radiation monitor. The abdomen should be monitored during pregnancy
• The extremities should be monitored during interventional procedures when the radiologist’s hands are in close proximity to the useful beam.
• Nuclear medicine technologists should wear extremity monitors when handling millicurie quantities of radioactive material.
• The occupational radiation monitoring report must contain a number of specific items of information
• Exposure data that must be included on the

  form (Occupational Rad Monitoring Report) include:

  • current exposure
  • cumulative annual exposure
• Separate radiation monitors, such as extremity monitors or fetal monitors, are identified separately from the whole-body monitor
• Occasionally, if occupational exposure involves low

  energy radiation, the dose to the skin might be greater

  than the dose of penetrating radiation
• When an occupational radiation monitoring

  program is established, the supplier of the

  monitor should be informed of the type of

  radiation facility involved.

  This information influences the method of calibration of monitors and control monitors
• The control monitor should never be stored in or adjacent to a

  radiation area.
• All monitors should be returned to the supplier

  together and in a timely fashion, so they can be

  processed together. True or False?

  True
• Protective gloves and aprons are available in

  many sizes and shapes. These usually are

  constructed of lead-impregnated vinyl