FDA Approves First 7 Tesla MRI Device

The first 7 tesla (7T) magnetic resonance imaging (MRI) device has been approved by the US Food and Drug Administration (FDA).

The approval of Magentom Terra, a 7T MRI system designed by Siemens Medical Solutions Inc., more than doubles the available magnetic field strength for use in the US. Its approval was based on comparisons to a predicate device and sample clinical images.

Prior to its approval, the greatest approved field strengths for magnet fields measured by tesla were 3T MRI scanners.

The Magnetom Terra was reviewed by the FDA through a 510(k) premarket submission, intended to demonstrate substantial equivalence between a new device and legally marketed predicate device.

The FDA also reviewed radiofrequency subsystem safety, as well as comparative study data of 35 patients to undergo imaging under the 7T device and a 3T device. The 7T-acquired images were of diagnostic quality, according to board-certified radiologists who reviewed the comparison, and was an improvement from 3T imaging in some cases.

“The overall image quality of MRI improves with higher magnetic field strength,” Robert Ochs, PhD, director of the Division of Radiological Health in the FDA’s Center for Devices and Radiological Health, said. “The added field strength allows for better visualization of smaller structures and subtle pathologies that may improve disease diagnosis.”

The Magnetom Terra is designated for patients who weigh 66 pounds or more, and is limited to extremity examinations.