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

Frank G. Shellock, Ph.D., FACR, FISMRM
Adjunct Clinical Professor of Radiology and Medicine
Keck School of Medicine, University of Southern California
www.MRIsafety.com

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 medical product is a “passive implant” (i.e., the implant serves its function without supply of electrical energy or any source of power other than that directly generated by the human body or gravity) 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. Notably, there are numerous reports that describe placement of vascular stents, coils, filters, and other metallic implants or devices using MR-guided or interventional procedures that include the use of 1.5- and 3-Tesla scanners, illustrating that patients with certain implants may immediately undergo MRI exams. Additionally, a patient or individual with a nonferromagnetic passive implant is allowed to enter the room associated with an MRI system operating at 3-Tesla or less immediately after the implantation of the medical product.

For a passive implant that does not state a "wait" period in the Instructions for Use (IFU) or product 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 IFU or product labeling.

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

The information above specifically pertains to magnetic field-related force and torque and, thus, further consideration must be given to RF-induced heating for an implant or device.

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

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05/2025