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MR safety training Simone Kühn, Pieter Vandemaele & Ruth Seurinck. Overview. The scanner Dangers in around the scanner In case of an emergency Emergency numbers Emergency procedure Reporting adverse events Safety checklists. The scanner. Dangers in and around the scanner. - PowerPoint PPT Presentation
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Overview
The scanner Dangers in around the scanner In case of an emergency Emergency numbers Emergency procedure Reporting adverse events Safety checklists
The scanner
Dangers in and around the scanner
Static magnetic field Gradient fields Highfrequency fields Laser-light Helium discharge Phantom leakage
Static magnetic fieldThe static magnetic field is ALWAYS on even
when the scanner is not in use!!!
projectile effecteverything that is ferromagnetic becomes a
projectile when brought into the scanner roomtorsion and translation forces: ferromagnetic
objects will attempt to align with the magnetic field
Metal objects becoming projectiles!!!
Melon in the Scanner
Static magnetic fieldmagnetohydrodynamic effect
phenomena arising from the motion of electrically conducting fluids in the presence of electric and magnetic fields
vertigo, nausea and phosphenes may relate to this
prevent this by restricting quick and side to side movement of the head when in the magnetic field
Static magnetic fieldTo ensure safety of participants:
MRI safety checklist has to be filled in and signed for each and every measurement
NO RISKS (www.mrisafety.com)
Less familiar exclusion criteria: transdermal medication patches (often contain a
metallic layer) make-up containing metal
Static magnetic fieldTo ensure safety of participants:
before you start working at the scanner make sure that you take off everything that contains metal
before entering the scanner room make sure that the subject has taken off everything that contains metal mention examples explicitly: glasses, belt, keys, money,
mobile phone watch them carefully and let them take everything out
of their pockets let them take off their shoes (outside the scanner room)
when entering the scanner room let the subject enter first (you have to be perfectly sure that you have no metal on you)
Dangers in and around the scanner
Static magnetic field Gradient fields Highfrequency fields Laser-light Helium discharge Phantom leakage
Gradient fieldsperipheral nerve stimulation
momentary magnetic field gradients can induce currents in conductive material including nerve or muscle tissue
it is possible to induce currents sufficient to influence cardiac function
researchers have to monitor the subject and stop scanning immediately if peripheral nerve stimulation is reported
Gradient fieldsperipheral nerve stimulation
when positioning the subject in the scanner avoid any closed loops with their extremities
instruct subjects not to clasp their hands or cross their legs
Gradient fieldsacoustic noise
EPI sequences are especially loudparticipants have to wear hearing protection:
earplugs + headphonesearplugs have to decrease noise by 30 dB
Dangers in and around the scanner
Static magnetic field Gradient fields Highfrequency fields Laser-light Helium discharge Phantom leakage
Highfrequency fieldstissue heating and burns
absorbtion of radio frequency power by the tissue is described in terms of Specific Absorption Rate (SAR, Watts/kg)
guideline: less than 1°C change in tissue temperature; SAR < 4 Watts/kg for any 15min period
scanner calculates SAR and stops scanning if too high
especially dangerous with tatoos containing iron oxide, or transdermal medication patches
no use of synthetic blankets in the scanner
Dangers in and around the scanner
Static magnetic field Gradient fields Highfrequency fields Laser-light Helium discharge Phantom leakage
Laser-lightdamage to the eyes
instruct participant to close the eyes during positioning with the laser light
make sure to report if the laser-light does not show a cross any longer but only a point
Dangers in and around the scanner
Static magnetic fieldGradient fieldsHighfrequency fieldsLaser-lightHelium dischargePhantom leakage
Helium dischargerisk of frostbites
helium is odorless, not flammable, not toxic but extremely cold!!!
contact causes freezesif you come into contact:
do not rub frozen body parts remove clothes rinse with cold water cover body parts with sterile bandage contact physician immediately
Dangers in and around the scanner
Static magnetic field Gradient fields Highfrequency fields Laser-light Helium discharge Phantom leakage
Phantom leakagenickel containing aerosols
can cause cancer
therefore do not use leaking phantoms
avoid skin contact with the leaking substances
Participant STOP Participant is wedged in the bore Fire or voltage accidents Quench: life threatening danger Earthquake or explosion
In case of emergency
In case of emergency
participants get an emergency ball to signal any problem during scanning
when an individual becomes ill or injured he/she must be removed immediately from the magnetic environment
Participant STOP Participant is wedged in the bore Fire or voltage accidents Quench: life threatening danger Earthquake or explosion
In case of emergency
In case of emergencyparticipant is wedged in the magnet
bore (risk of crushes)press the stretcher – STOP button
to the right and left of the scanner at the communication system
the automatic brake of the patient table has to be released then you can pull the patient table out manually (handle is at the bottom of the patient table)
In case of emergencyparticipant is wedged in the magnet
bore (risk of crushes)if you are sure there is no risk anymore you
have to restart the patient table mechanism by pushing the in and out button after one another
Participant STOP Participant is wedged in the bore Fire or voltage accidents Quench: life threatening danger Earthquake or explosion
In case of emergency
In case of emergencyfire or voltage accidents
push the emergency-off button
this only stops the electricity not the magnet!!!
Participant STOP Participant is wedged in the bore Fire or voltage accidents Quench: life threatening danger Earthquake or explosion
In case of emergency
In case of emergencylife threatening danger due to
magnet or fireif a participant is restrained by a ferrous
object assess if the situation is life threatening if YES quench the magnet
Metal objects becoming projectiles!!!
Here you do NOT need to quench!!! No life in danger.
In case of emergencylife threatening danger due to
magnet or firequenching costs around 50.000 €decrease of field to 20mT in 20 seconds (elec.
implants are still disturbed from 0.5mT)sudden loss of the magnetic field can cause
freezing gases to enter the room, loud noiseNormally there is no helium leakage in the
magnet room
Participant STOP Participant is wedged in the bore Fire or voltage accidents Quench: life threatening danger Earthquake or explosion
In case of emergency
In case of emergencyearthquake or explosion
might lead to an uncontrolled quench: increased risk of helium leakage (DANGER)
oxygen level in the magnet room may decrease and may make breathing difficult (risk of suffocation)
during quenching condensation occurs therefore do not walk under the exhaust pipe lines
Emergency numbersFire 88 (don‘t use fire extinguisher!)All other medical emergencies: 81
What to do in case of emergency?
(e.g. Participant is unconscious)1. Get participant out of the scanner (use
bed)& call 81 (simultaneously)
2. Say on the phone:1. Where you are: MR dwarsgebouw Links
(tussen B1 & B2/between B1 & B2)2. What’s going on: ‘e.g. participant
unconscious’3. Your name4. Your internal number: 21240
3. Open all the exit doors for easy access
Reporting adverse eventsaccidents and injuries are to be reportedalso near accidents should be reported so we
can take precautions report to: Pieter Vandemaele
mail: [email protected]: 09 332 4820
MR safety checklistplease fill in now
DemonstrationsEmergency materialsEmergency procedure:
Emergency stop: Participant stop Operator stop
Phonecall & getting participant outOpening the doors