This presentation will describe the MRI related risks to patients with active implantable devices with respect to unintended electrical tissue stimulation. The mechanisms due to RF rectification and gradient induced electrical potential will be described using simplified circuit models. Standard test methods for characterizing device performance in the MRI environment will be described. Finally, risk mitigation strategies and MR Conditional labeling strategies will be reviewed.
TARGET AUDIENCE
MRI Technologists, Clinical Medical Physicists, Radiologists
PURPOSE
To review the MRI related risks to patients with active implantable devices with respect to unintended electrical tissue stimulation, describe the mechanisms that may produce unintended stimulation, review test methods for characterizing implanted device performance in the MRI environment, and describe methods for mitigating these risks.SUMMARY
The time varying radio-frequency (RF) and magnetic gradient fields associated with MRI can interact with active implanted medical devices and produce undesired electrical tissue stimulation. The mechanisms due to RF rectification and gradient induced electrical potential will be described in detail using simplified circuit models. The risks associated with unintended stimulation will be discussed in terms of typical cardiac rhythm and neurostimulation therapies. Finally, standard test methods described in TS10974[1] for evaluating device performance in the MRI environment will be described.
CONCLUSION
Implantable device engineering, rigorous testing and, and MR Conditional Labeling will expand safe access to MRI for patients with active implantable devices.
Medtronic Applied Physics Team: Riki Banerjee Ph.D., Arcan Etruk Ph.D., Yohan Kim Ph.D., Jiashu Li, Chanjoon Lee Ph.D., Lauren Tran Ph.D., Dave Kelly, Leonard Gramse, Tom Wyatt, Katlyn Johnson.