Tobias Gilk, M . Arch., a member of ACR’s MR Safety Committee –
(Patient Safety & Quality Healthcare, September/October 2006)
Emanuel Kanal, MD, FACR, FISMRM, AANG – (Good Morning America, abc News 08/22/05)
Chaljub et al (From the Study of the University of Texas Hospitals)
- With the increased use of higher strength field magnets and self shielded magnets, the maximum force of attraction increases dramatically.
- The increase of spatial gradients of the new active shielded magnets:
• No gentle, slowly increasing pull to provide feedback of ferromagnetic properties
• Maximum force much greater than for the same field strength unshielded magnet
• Distance/Time to react to force can be shorter than reaction time
• A 3T magnet with the same magnetic footprint as a 1.5T has four times the force
- MRI magnets are always ON, therefore projecting the magnetic field, which can be as much as 60,000 times more powerful than the Earth’s, 24/7. Equipment and consumables that are “safe” 99% of the time become “unsafe” near MRI
- The large invisible magnetic field that is projected by an MRI machine and extends in 3 dimensions cannot be touched, seen, smelled, or sensed in any other way.
- Many objects that are “seemingly safe” and appear not to contain iron or any other ferromagnetic materials, for example, sandbags can contain ferrous materials even though one would not think so.
- Non MR staff in MRI suite, for example, cleaning personnel or the family members accompanying patients.
- Labeling on devices or in documentation can be confusing: “MR safe”, “MR not safe” and “MR conditional” - these terms are not intended to be used without further specifying the particular MR environment conditions where the devices have been tested.
- Sharing imaging staff between different modalities. What can be safe in CT environment can become very dangerous in MR environment.
- In case of emergency, if you need to shut off the MRI magnet, there can be health hazards and $20,000-$500,000 cost associated.
- Combination of complacency, work-arounds for speed, and diffuse responsibility