Use of RFID transponders in MRI systems
In all their applications, RFID transponders are required to be unnoticeable, imperceptible and at the same time with the highest mechanical resistance and electrical performance. When considering their use in hospitals and medical centers, the transponders must also be compliant with specific healthcare sector requirements, such as meeting the strict standards for safety and compatibility in Magnetic Resonance Imaging (MRI).
In fact, any device containing metal or conductive elements, even passive such as an RFID transponder, used or present during an MRI scan, can lead to unintended and dangerous interactions with the electromagnetic field, creating both safety issues (excessive heating or displacement that could harm the patient) and unwanted artefacts (imaging anomalies) that could compromise the diagnosis.
For this reason, to safely use RFID transponders during an MRI examination it is necessary to have performed accurate MR validation testing and to obtain the “MR conditional” label which guarantees that the labelled device poses no known hazards in a specified MR environment with specified conditions of use.
Because the MR Conditional label focuses on safety, it guarantees that both device heating and displacement due to the magnetic field cannot, in any case, put at the risk the safety of the patient, of the hospital personnel or of the medical equipment. The MR Conditional label however does not impose any limitation on the artefact size since artefact doesn’t have a primary safety impact. Nevertheless, artefact’s presence can impact the medical diagnosis and it is thus important to reduce the artefact caused by the RFID tag to a minimal size.
Datamars’ MR testing white paper and the obtainment of the MR conditional label
To ensure the maximum quality and safety of its transponders and thus its widest use in any healthcare applications, Datamars has made an in-depth analysis of each component used in its UHF LaundryChipsTM and concluded that reducing the magnetic level of the tag antenna was the key to make the RFID transponders “neutral” from a force and torque point of view and to reduce the artefact size. The patented technology used by Datamars in its UHF LaundryChipsTM antenna wire allowed to remove the issue of magnetization of the tag material, making its UHF transponders almost invisible to the MRI magnetic field and letting reaching in this way two great results: on one hand the highest level of safety for patient and on the other hand a minimum level of artefact (<5 mm) such as not to influence the medical diagnosis. Datamars’ UHF LaundrychipsTM 301 and 401, in particular, obtained the “MR conditional” label that guarantees that a patient wearing a garment or a textile with embedded its transponder can be safely scanned in an MR system at 1.5 or 3 Tesla (without heating nor force and torque effects), while having a minimal impact on the MR images.
“We are proud to be the only RFID manufacturer in the market to use a patented technology to manufacture our UHF LaundryChipsTM antennas which makes them perfectly safe to use in MRI environment, producing a minimal image artefact” says Julien Buros, Datamars Textile ID Product and Services Director. “Unlike us, our competitors use technologies with a strong trade off: using metal-based antennas that can either be mechanically strong but generating large artefacts or feature small artefacts but being mechanically too weak to resist the harshest laundry conditions.”