2. MRI safety: key points
• What is MRI?
• What are the risks?
• Why all the fuss?
• MRI deaths
• Burns from MRI
• How do we manage the risk
• Education and training
3. What is an MRI Scanner?
• MRI is an extremely powerful superconducting
magnet
• High powered radiowaves to energise hydrogen
protons
• Additional RF gradients to manipulate
electromagnetic fields to enable the acquisition of
images of the body
4. What are the risks?
• Metal in the high magnetic field
• Contraindicated implant in patient
• Patients with metal in their body
• Burns
• Noise
5. Why all the fuss about MRI safety?
• MRI uses an extremely powerful magnet
• The magnet is always on!
• The magnetic field reaches to the edge of the
magnet room and beyond in some places
• i.e. The Magnetic field can exert an attractive force
even at the edges of the room
• The magnetic field is silent
6. Why all the fuss about MRI safety?
• Ferromagnetic objects taken into the magnet room
can become potentially fatal missiles
• People have died in MRI rooms because unsafe
objects have been taken into the room
• Many serious impact injuries
16. Why all the fuss?
• This is not how we get our patients to stay still!
17. Some youtube videos
• http://www.youtube.com/watch?v=plvIEf7JsKo
• http://www.youtube.com/watch?v=-5S9jmr9-7w
• http://www.youtube.com/watch?
NR=1&v=vIQaGt_fkkw&feature=endscreen
• http://www.youtube.com/watch?v=byRIwDk21sw
• http://www.youtube.com/watch?v=7g5UVrOt2CI
• http://www.youtube.com/watch?v=5z33ZcDgavY
• But MRI can be fun too
•http://www.youtube.com/watch?
v=M2OdAp7MJAI
18. It isn’t just a problem in other places?
• Scissors (more than once)
• Hand-held magnet for checking implants
• Metal support / frame
• Walking sticks with metal handles
• Coins
• These incidents or near misses were not generally
a result of a lack of knowledge rather lapses in
awareness or concentration
• Incidents are recorded and reviewed on DATIX
19. MRI missile death
• Michael Columbini
• http://www.youtube.com/watch?v=0nA-UceHMqc
•
20. MRI missile death
• Most recent death in MRI was an engineer in
Morocco
• Small room, room being used for storage
• Service on blower motor, part ~ 14Kg
• Got too close to the magnet
• Incapacitated and found dead the next morning
• See the FDA MAUDE database
• Implications for lone working
21. How do we minimise the risk of missiles?
• Manage and control the environment
• Control persons entering the controlled area
• Control equipment entering the controlled area
• Control the patient journey
• Staff training
22. The Outer controlled area
• Generally referred to as ‘the controlled area’
• Everyone entering this area must complete a MR
safety checklist – no exceptions!
• Only authorised staff know the code for the door
• If an authorised member of staff lets someone into
the controlled area they become responsible for
them
• Always be vigilant of others in this area as well as
observing your own safety
• Don’t be afraid to challenge a member of staff
23. The inner controlled area
• Generally referred to as ‘the magnet room’
• Absolutely no metal to be taken into this area
• unless you are 100% sure it is not ferromagnetic and it
has been tested by a MR physicist/ radiographer and is
labelled as MR conditional (or with blue and white tape)
• Get into a routine of removing wallets/purses,
jewellery, watches, car keys, pager, lanyards,
piercings, mobile phones
• Pat yourself down before entering room
• Become paranoid
24. The MRI checklist
• Staff must be checklisted before entering the controlled
area
• Ensure staff member is safe to enter magnet room
• Raises awareness of the risks in MRI
• Patients should complete the checklist prior to attending
for imaging
• MR checklist performed by an authorised member of staff
• The MRI checklist has two main functions
• To ensure the patient has no contraindicated implants /
or metallic object inside them
• To sure they have no metallic objects on their person
25. • MRI safety
checklist
• All patients /
comforter/ carer
• All staff/ visitors
entering
controlled area
26. Why all the fuss about patient implants?
• MHRA guidelines state that procedures should be in
place to determine whether a patient has implants and
whether they are MR safe, MR Conditional or MR Unsafe
• At INS pacemakers and aneurysm clips are absolute
contraindications
• Majority of implants safe
• Complexity of medical implants increasing
• Many devices are MR conditional
• Duty bound to check safety of implant
28. MRI death: Aneurysm clip
• 74 yr old lady referred for MRI scan
• Screening picked up that she had a aneurysm clip
• Scanning did not proceed
• Staff contacted surgeon to confirm type of
implanted clip
• Staff checked clip, was deemed to be safe
• Patient was brought down to be scanned
• Severe haemorrhage and died
• Turns out the surgeon got the clip wrong
• The actual clip that was implanted was not safe for
MRI
29. Burns
• Probably the most common cause of injury to patients in
MRI
• (100’s of cases of burns reported)
• The MRI scanner uses high power radiofrequency waves
• These can lead to currents being induced in the tissue
• Where the loops are large enough these can lead to burns
at skin contact points
• Large metallic implants are also a concern i.e. long
orthopaedic implants
• Tattoos
33. Patient positioning
• The manufacturers provide specific guidance on
positioning the patient
• The skin-skin or bore-skin contact points must be avoided
by using the insulating/comfort pads provided
• Also avoid loops such as from hands being clasped,
overlapping ankles, knees
• Use the pads provided to avoid these contact points
• This is particularly important in anaesthetised patients
• Also, perhaps more of a risk for patients wearing gowns
rather than scrubs
35. Burns from patient monitoring equipment
• Equipment leads and cables of monitoring
equipment have also been known to cause injury in
MRI
• Ensure the equipment you are using is MRI
conditional or MRI safe
• MRI conditional does not mean MRI safe, know
what the conditions are
• Know the safe conditions of use for your
monitoring equipment i.e. do not take it over the red
and white line on the scanning room floor
42. Safety features of the MRI
• The MRI system is a CE marked device
• Additional features for safety are
• Ear protection must always be given to the patient
• A call button must be given to the patient
• It can be helpful to tape this to the patients gown
• Quick release bed top
• Detachable couch
• Retractable arm rests to help patient move on couch
• Emergency stop: cut power (red button on scanner)
• Quench
(red button under plastic protection on wall...you should
never need to touch this, alert authorised MR
radiographer)
43. Other tips for safe practice
• You know your job and the service runs smoothly,
however, be particularly mindful when:
• New staff are present
• Some change in upstream working practice occurs
• Patients from other hospitals
• Patient transported differently
• New equipment in the area
• Radiographers, Radiologists and MRI physics
available to advise
• In the event of an emergency, remember where
you are and don’t panic
44. Your responsibilities
• Ensure that you are safe to enter the magnet room
• Get into a routine of removing all your accessories
• Do not take anyone into the magnet room unless
you know for certain they are safe
• Pat yourself down before entering room
• Observe the safety of others
• Know what to do in emergency situations
45. Education and training
• Ensure you have read, understood and signed the
local rules for MRI
• Copies for Anaesthetists, ODP’s, nurses
46. Final thought
• MRI is an intrinsically safe technique made unsafe
by people, implants, peripheral devices and bad
procedures
• Provided the following are applied in practice,
incidents should be very unlikely:
• No inappropriate objects (metal/ ferromagnetic)
taken into the MR room
• Correct use of MR safe and conditional equipment
• Good implant screening of patient
• Ear protection
• Good patient positioning
47. ….and just when you think you’ve seen it all!
• Ladycare magnet ...
