MR safety training Simone Kühn, Pieter Vandemaele & Ruth Seurinck

MR safety trainingSimone 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 field • The static magnetic field is ALWAYS on even when the scanner is not in use!!! • projectile effect • everything that is ferromagnetic becomes a projectile when brought into the scanner room • torsion and translation forces: ferromagnetic objects will attempt to align with the magnetic field

Metal objects becoming projectiles!!!

Melon in the Scanner

Static magnetic field • magnetohydrodynamic 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 field • To 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 field • To 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 fields • peripheral 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 fields • peripheral 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 fields • acoustic noise • EPI sequences are especially loud • participants have to wear hearing protection: earplugs + headphones • earplugs have to decrease noise by 30 dB

Highfrequency fields • tissue 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-light • damage 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

Helium discharge • risk of frostbites • helium is odorless, not flammable, not toxic but extremely cold!!! • contact causes freezes • if 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 leakage • nickel containing aerosols • can cause cancer • therefore do not use leaking phantoms • avoid skin contact with the leaking substances

In case of emergency • 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 emergency • participant 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 emergency • participant 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 emergency • fire or voltage accidents • push the emergency-off button • this only stops the electricity not the magnet!!!

In case of emergency • life threatening danger due to magnet or fire • if 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 emergency • life threatening danger due to magnet or fire • quenching 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 noise • Normally there is no helium leakage in the magnet room

In case of emergency • earthquake 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 numbers • Fire 88 (don‘t use fire extinguisher!) • All other medical emergencies: 81

What to do in case of emergency? (e.g. Participant is unconscious) • Get participant out of the scanner (use bed)& call 81 (simultaneously) • Say on the phone: • Where you are: MR dwarsgebouw Links (tussen B1 & B2/between B1 & B2) • What’s going on: ‘e.g. participant unconscious’ • Your name • Your internal number: 21240 • Open all the exit doors for easy access

Reporting adverse events • accidents and injuries are to be reported • also near accidents should be reported so we can take precautions • report to: Pieter Vandemaelemail: pieter.vandemaele@ugent.betel: 09 332 4820

MR safety checklist • please fill in now

Demonstrations • Emergency materials • Emergency procedure: • Emergency stop: • Participant stop • Operator stop • Phonecall & getting participant out • Opening the doors

Thank your for your attention!

MR safety training Simone Kühn, Pieter Vandemaele & Ruth Seurinck