RADIATION EXPOSURE -

Patient, (general public ??)
Xrays
ALARA principle: Decrease exposure to patient by
 Increasing kVp of beam
 Decreasing mAs
 Filtration of beam
 Collimation to restrict field size (decrease patient volume exposed and decrease scatter)
 Shielding of critical organs (eg when abdominal xray done, gonadal shielding)
 Increase SOD and SID
 Increased speed of image receptor or using CR devices
 Specialized film processing
Know when patients are pregnant and weigh the benefits of the examination against the risks
Decrease the time that exposure needs to be done
Shielding
Diagnostic radio-isotopes
Limit miss-administrations by:
 Labelling vial shields with name of radiopharmaceutical (RP)
 Labelling syringes with RP name and patient name
 Identity of patient verified by 2 means
 Establish if patient pregnant/ breast feeding
 Written directive to be followed when RP administered
 Stop breastfeeding until necessary
MRI
 Limit use of MRI in patients with implants, prosthesis
 Avoid MRI in patients who have pacers, brain surgery clips
 Keep to the power deposition limit given
 Large exhaust system must be present in room to remove gas of Helium quench
 Follow max limits on magnetic fields (static and varying)
 Remove all ferromagnetic objects from patient before taking into room
 Do not bring free ferromagnetic objects near MRI while patient in the room
 Wear suitable ear protection
 Properly inform patient of the procedure, risks and benefits and adverse events.
 Communicate with patient during procedure to prevent him from feeling isolated
Radiographer, support staff, radiologist
Xrays
Limit exposure by:
 Time: Don’t activate the xray tube when staff near source
 Distance:
o Stand as far as possible from Xray tube without negatively influencing the quality of the film (recommended 2m)
o If support staff hold patient, they should not be in the primary beam
 Shielding:
o Wear protective clothing (lead apron, goggles, thyroid shield, gloves)
 Declare pregnancy and limit exposure during pregnancy
 Wear personnel dosimetry to monitor exposure
Diagnostic radio-isotopes
Limit time spent near radiation source by understanding task to be performed and using appropriate equipment
Use of tongs/handling devices
Contamination control and surveys
 Wear protective clothing (lab coats, disposable gloves, closed shoes)
 Handling precautions
 Routine survey of personel and work surfaces for contamination
 Wash hands after handling radio-active material
 If contamination occur – gentle cleansing with soap and warm water
 Not eat or drink near radio-active material
 Discard radio-active materials into radio-active waste disposal containers (shielding of waste areas)
 Report serious spills/accidents to radiation safety officer
Radio-active material spills
 First aid more important than personnel decontamination, more important than facility decontamination
MRI
 Wear no metallic objects when coming near MRI room
 Faraday cage
 People that have pacemakers should not wander freely about area of MRI
 Even though no adverse events proven with static magnetic fields, avoid MRI in early pregnancy
 Clearly marked restricted area
 Placement of MRI where most likely to interfere with RF of other instruments or where less likely to be interfered with other RF waves