MRI Compatibility Numerical Simulation & Experimental Testing

Magnetic resonance imaging (MRI) is a non-invasive procedure that is essential for disease detection, diagnosis, and treatment management. However, for millions of patients with implanted medical devices such as pacemakers, neurostimulators, and stents, this life-saving imaging procedure can pose risks. Because many implanted devices contain metal, they can interact with the static, gradient, and radiofrequency (RF) magnetic fields of an MRI machine, which can damage the device, create image artifacts, and harm the patient through device malfunction, heating, or magnetically induced force or torque of the device if not properly anticipated.

Accurate labeling for implantable devices that follows U.S. Federal Food & Drug Administration (FDA) guidelines, “Testing and Labeling Medical Devices for Safety in the Magnetic Resonance (MR) Environment,” communicates MRI-related risks to patients and MRI scanner operators. How can medical device manufacturers ensure that all their product labeling meets regulatory expectations?
Exponent can help device manufacturers meet these requirements by performing MRI compatibility testing of medical devices and finite element analysis (FEA) simulations of their interaction with the static, RF, and gradient magnetic fields. With the application of advanced numerical simulations, our MRI laboratory team can assess risks by evaluating and identifying worst-case scenarios that may occur while scanning a patient with an implantable device. Through careful analysis of this data, we assist our clients in the feasibility and verification stages of product development as they optimize their device designs for use in an MRI environment.

We also help medical device manufacturers meet regulatory labeling requirements through physical testing of the worst-case matrix for each product by leveraging our in-house benchtop RF and gradient coils, accredited by the American Association for Laboratory Accreditation (A2LA). In this way, we can provide analysis and labeling guidelines to help clients prepare their submissions to regulatory authorities and formulate a strategy for marketing their devices.

Exponent’s team offers the following services:

We have the in-house capability—and are accredited to ISO 17025—to test at 1.5 T and 3 T in accordance with all applicable FDA guidance and ASTM International and ISO standards, listed below:

  • Guidance for Industry and FDA Staff: Testing and Labeling Medical Devices for Safety in the Magnetic Resonance (MR) Environment, issued on May 20, 2021
  • Guidance for Industry and FDA Staff: Assessment of Radiofrequency-Induced Heating in the MR Environment for Multi-Configuration Passive Medical Devices, issued on March 22, 2016
  • ASTM F2052 – Standard Test Method for Measurement of Magnetically Induced Displacement Force on Medical Devices in the Magnetic Resonance Environment 
  • ASTM F2119 – Standard Test Method for Evaluation of MR Image Artifacts from Passive Implants 
  • ASTM F2182 – Standard Test Method for Measurement of Radiofrequency-Induced Heating Near Passive Implants During Magnetic Resonance Imaging 
  • ASTM F2213 – Standard Test Method for Measurement of Magnetically-Induced Torque on Medical Devices in the Magnetic Resonance Environment 
  • ASTM F2503 – Standard Practice for Marking Medical Devices and Other Items for Safety in the Magnetic Resonance Environment 
  • ISO/TS 10974:2018 – Assessment of the Safety of Magnetic Resonance Imaging for Patients with an Active Implantable Medical Device

Exponent also has arrangements with regional research institutions to conduct studies at higher and lower field strengths, as required. Our consultants are active in the standards committees related to MRI compatibility testing and routinely assist our clients in applying the standard methods to their specific products and indications.

Medical Devices of Interest for Interaction with Magnetic Resonance

We have performed MRI simulation and testing on a variety of passive and active medical devices including implantable cardiovascular, pulmonary, spinal, neurosurgical, and orthopedic products. We have also tested non-implantable medical devices designed to be used within the MRI environment.

Our biomedical engineering and sciences laboratory in Philadelphia has been accredited for MRI safety evaluation for passive devices since 2007, and our ISO/IEC 17025 scope of accreditation, recently renewed in 2021, covers test methods for active devices, such as nerve stimulators and pacemakers, that communicate with the body to deliver therapies.

We provide analysis and guidance to clients regarding FDA submissions in the context of performance to standards for device malfunction, image artifacts, localized heating, displacement, and torque due to interactions with the magnetic and electromagnetic fields associated with an MRI scanner. We also assist manufacturers with failure analysis when needed, including investigation of injuries in the MRI environment, and support them through the complete medical device product lifecycle—including corrosion analysis and battery assessments. 

Exponent has evaluated many devices for clients including:

  • Neurointerventional devices: aneurysm clips and coils, hydrocephalus valves/shunts, neurostimulators 
  • Vascular implants: stents, valves, filters 
  • Interventional instruments: catheters, guidewires, endoscopes 
  • Orthopedic/spinal devices: joint prostheses, fracture fixation hardware, fusion and deformity constructs 
  • Medical monitoring and support equipment: ventilators, drug pumps, monitoring equipment with carts and gas cylinders
  • Electrophysiology devices: pacemakers, implantable cardioverter defibrillators 
  • Others: handheld surgical instruments, implantable (cochlear) hearing devices.

Professionals

Knowledge

News & Events