Miscellaneous Implants and Devices

Many miscellaneous implants, materials, devices, and objects have been tested with regard to MRI procedures and the MRI environment.

For example, various types of firearms have been tested in the MRI environment. These firearms exhibited strong ferromagnetism. In fact, two of the six firearms evaluated discharged in a reproducible manner while in the MR system room. Obviously, firearms should remain outside of the MRI environment to prevent problems or possible injuries.

MRI-guided biopsy, therapeutic, and minimally invasive surgical procedures are important clinical applications that are performed on conventional, open-architecture, or “double-donut” MR systems specially designed for this work. These procedures present challenges with regard to the instruments and devices that are needed to support these interventions.

Metallic surgical instruments and other devices potentially pose hazards (e.g., missile effects) or other problems (i.e., image distortion that can obscure the area of interest) that must be addressed to apply MRI-guided techniques effectively.

Various manufacturers have used “weakly” ferromagnetic, nonferromagnetic or nonmetallic materials to make special instruments for interventional MRI procedures.

Other medical products and devices have been developed with metallic components that are either entirely nonferromagnetic or made from metals that have a low magnetic susceptibility (e.g., titanium, non-magnetic types of stainless steel, etc.) that are acceptable for use in the MRI environment.

MRI Information at 3-Tesla and Miscellaneous Implants and Devices.
Several implants and devices have been tested in association with 3-Tesla MR systems. Refer to The List to determine information about specific miscellaneous implants and devices assessed at 3-Tesla.

REFERENCES

Go KG, Kamman RL, Mooyaart EL. Interaction of metallic neurosurgical implants with magnetic resonance imaging at 1.5-Tesla as a cause of image distortion and of hazardous movement of the implant. Clin Neurosurg 1989;91:109-115.

Kanal E, Shaibani A. Firearm safety in the MR imaging environment. Radiology 1994;193:875-876.

Lufkin R, Jordan S, Lylyck P, et al. MR imaging with topographic EEG electrodes in place. AJNR Am J Neuroradiol 1988;9:953-954.

Planert J, Modler H, Vosshenrich R. Measurements of magnetism-forces and torque moments affecting medical instruments, implants, and foreign objects during magnetic resonance imaging at all degrees of freedom. Medical Physics 1996;23:851-856.

Shellock FG. Biomedical implants and devices: assessment of magnetic field interactions with a 3.0-Tesla MR system. J Magn Reson Imaging 2002;16:721-732.

Shellock FG. MR-compatibility of an endoscope designed for use in interventional MR procedures. AJR Am J Roentgenol 1998;71:1297-1300.

Shellock FG. Magnetic Resonance Procedures: Health Effects and Safety. CRC Press, LLC, Boca Raton, FL, 2001.

Shellock FG. MR safety update 2002: Implants and devices. J Magn Reson Imaging 2002;16:485-496.

Shellock FG. Metallic neurosurgical implants: assessment of magnetic field interactions, heating, and artifacts at 1.5-Tesla. Radiology 2001;218:611.

Shellock FG. Surgical instruments for interventional MRI procedures: assessment of MR safety. J Magn Reson Imaging 2001;13:152-157.

Shellock FG, Shellock VJ. Ceramic surgical instruments: evaluation of MR-compatibility at 1.5-Tesla. J Magn Reson Imaging 1996;6:954-956.

Shellock FG, Shellock VJ. Evaluation of MR compatibility of 38 bioimplants and devices. Radiology 1995;197:174.

To SYC, Lufkin RB, Chiu L. MR-compatible winged infusion set. Comput Med Imag Graph 1989;13:469-472.

Zhang J, Wilson CL, Levesque MF, Behnke EJ, Lufkin RB. Temperature changes in nickel-chromium intracranial depth electrodes during MR scanning. AJNR Am J Neuroradiol 1993;14:497-500.