According to Chaljub, et al. (2001), accidents related to ferromagnetic oxygen tanks and other gas cylinders that can become projectiles may be increasing. In fact, missile-related accidents for these objects as well as other items have resulted in at least one fatality, several injuries, damage to MR systems, and down-time (i.e. loss of revenue) for many MRI centers.

Therefore, MRI facilities must implement a policy for safe administration of oxygen to patients undergoing MR procedures. In lieu of utilizing pipes to directly deliver gases to patients, the use of non-magnetic (usually aluminum) gas cylinders is one means of preventing “missile effect” hazards in the MR environment. Non-magnetic oxygen tanks and cylinders for other gases are commercially available from various vendors.

MRI centers should have a sufficient number of nonmagnetic oxygen tanks and strict policies in place to prevent staff members from introducing ferromagnetic objects into the MR environment. Notably, some hospital-based MRI facilities have nonmagnetic oxygen tanks used throughout their buildings to prevent projectile accidents.

Nonmagnetic tanks must be prominently labeled and/or color-coded to avoid confusion with magnetic cylinders. Additionally, only regulators tested and demonstrated to be acceptable for use in a high magnetic field environment should be used with the nonmagnetic cylinders. Furthermore, all healthcare workers that work in the MR environment must be informed regarding the fact that only nonmagnetic oxygen and other gas cylinders are allowed into the MR system room.

Nonmagnetic or weakly magnetic (i.e. MR Conditional) oxygen regulators, flow meters, cylinder carts, cylinder stands, cylinder holders for wheelchairs, and suction devices are also commercially available to provide safe respiratory support and management of patients in the MR environment.

REFERENCES

Chaljub G, et al. Projectile cylinder accidents resulting from the presence of ferromagnetic nitrous oxide or oxygen tanks in the MR suite. Am J Roentgenol 2001;177:27-30.

Colletti PM. Size “H” oxygen cylinder: Accidental MR projectile at 1.5-Tesla. J Magn Reson Imag 2004;19:141-143.

ECRI Institute. Patient Death Illustrates the Importance of Adhering to Safety Precautions in Magnetic Resonance Environments. ECRI Institute, Plymouth Meeting, PA, Aug. 6, 2001.

Jolesz FA, et al. Compatible instrumentation for intraoperative MRI: Expanding resources. J Magn Reson Imag 1998;8:8-11.

Keeler EK, et al. Accessory equipment considerations with respect to MRI compatibility. J Magn Reson Imag 1998;8:12-18.

Shellock FG, Crues JV, Editors. MRI Bioeffects, Safety, and Patient Management. Biomedical Research Publishing Group, Los Angeles, CA, 2014.