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

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)

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

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

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


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

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


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

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

In case of emergencyfire or voltage accidents

push the emergency-off button

this only stops the electricity not the magnet!!!

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

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

MR safety training Simone Kühn, Pieter Vandemaele & Ruth Seurinck

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Transcript of MR safety training Simone Kühn, Pieter Vandemaele & Ruth Seurinck