Medical Device MRI Safety Testing: Where should you measure temperature when testing RF-induced heating of a complicated structure?

Regarding MRI safety, testing the radio-frequency-induced heating of implanted medical devices is important to prevent harm to patients during MR imaging. ASTM F2182 was developed to describe methods for performing these tests. If the medical device has a complicated structure, where on the device should you measure the temperature? The standard doesn’t say.

To answer this question, MED Institute has developed computational methods for predicting RF-induced heating on complicated structures such as inferior vena cava (IVC) filters.

Using an IVC filter as an example, a finite element model of the RF coil and the filter simulates the electrical field and resultant heating of the human tissue adjacent to the device. The computational analysis using COMSOL Multiphysics® provides a temperature map of the device so that the worst case location of heating can be determined. Physical testing may then be performed with the temperature probes placed at the identified worst case heating locations. In this case, the analysis indicated that the greatest temperature rise caused by the presence of the IVC filter would be in the tissue near the hook. The experimental temperature increase results agreed with the computational analysis results.

Case Study 2 image

On the basis of this safety evaluation, the IVC filter was able to be marked as MR Conditional—it is safe for MR scanning under defined conditions.

COMSOL Multiphysics is a registered trademark of COMSOL AB.

For more information, please visit our website www.medinstitute.com.

sign up

One thought on “Medical Device MRI Safety Testing: Where should you measure temperature when testing RF-induced heating of a complicated structure?

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s