Guidelines for the Management of the Post-Operative (Post-Op)
Patient Referred for an MRI Examination

 

There is often confusion regarding the issue of performing a magnetic resonance imaging (MRI) examination during the post-operative period in a patient with a metallic implant or device. Studies have supported that, if the metallic object is a “passive implant” (i.e., there is no electronically-activated component or power source associated with the operation of the device) and it is made from nonferromagnetic material, the patient may undergo an MRI exam immediately after implantation using an MR system operating at 3-Tesla or less. In fact, there are several reports that describe placement of vascular stents, coils, filters, and other metallic implants using MR-guided procedures that include the use of high-field-strength (1.5- and 3-Tesla) scanners. Additionally, a patient or individual with a nonferromagnetic, passive implant is allowed to enter the MRI environment associated with a scanner operating at 3-Tesla or less immediately after the implantation of the device.

Importantly, for a passive implant that does not state a "wait" period in the Instructions for Use (IFU) or MRI labeling, there is no need to delay the MRI examination for the patient. To date, very few passive implants indicate a wait period in the MRI labeling.

For patients with implants that are “weakly magnetic” but rigidly fixed or otherwise anchored in the body (e.g., orthopedic implants or other devices), these patients may undergo MRI immediately after implantation of the device.

The information above pertains to magnetic field interactions (i.e., force and torque) and, thus, further consideration must be given to MRI-related heating for the implant or device.

Special Note: If there is any concern regarding the integrity of the tissue with respect to its ability to retain the implant or object in place or the implant cannot be properly identified, the patient or individual should not be exposed to the MRI environment.

SUPPORTING REFERENCES

Bueker A, et al. Real-time MR fluoroscopy for MR-guided iliac artery stent placement. J Magn Reson Imag 2000;12:616-622.

Manke C, Nitz WR, Djavidani B, et al. MR imaging-guided stent placement in iliac arterial stenoses: A feasibility study. Radiology 2001;219:527-534.

Rutledge JM, et al. Safety of magnetic resonance immediately following Palmaz stent implant: A report of three cases. Catheter Cardiovasc Interv 2001;53:519-523.

Sawyer-Glover A, Shellock FG. Pre-MRI procedure screening: recommendations and safety considerations for biomedical implants and devices. J Magn Reson Imag 2000;12:92-106.

Shellock FG. Guidelines for the Management of the Post-Operative Patient Referred for a Magnetic Resonance Procedure. Signals, No. 47, Issue 3, pp. 14, 2003.

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

Shellock FG, Crues JV. MR procedures: Biologic effects, safety, and patient care. Radiology 2004;232:635-652.

Shellock FG, Crues JV. Editors. Bioeffects, Safety, and Patient Management. Biomedical Research Publishing Group, Los Angeles, CA. 2020

Shellock FG. Reference Manual for Magnetic Resonance Safety, Implants, and Devices: 2020 Edition. Biomedical Research Publishing Group, Los Angeles, CA. 2020

Spuentrup E, et al. Magnetic resonance-guided coronary artery stent placement in a swine model. Circulation 2002;105:874-879.

Teitelbaum GP, et al. MR imaging artifacts, ferromagnetism, and magnetic torque of intravascular filters, stents, and coils. Radiology 1988;166:657-664.

Teitelbaum GP, et al. Ferromagnetism and MR imaging: Safety of cartoid vascular clamps. Am J Neuroradiol 1990;11:267-272.

Teitelbaum GP, Ortega HV, Vinitski S, et al. Low artifact intravascular devices: MR imaging evaluation. Radiology 1988;168:713-719.

Teitelbaum GP, et al. Evaluation of ferromagnetism and magnetic resonance imaging artifacts of the Strecker tantalum vascular stent. Cardiovasc Intervent Radiol 1989;12:125-127.

09/2023