Before attaching RFID transponders to garments likely to be worn by patients undergoing an MRI scan in hospitals, as well as linen, need to be accurately tested before putting into use.
RFID transponders (microchips) are widely used in hospital and healthcare facilities to track and trace any type of textile during their washing cycles. Embedded in patient gowns, linen and surgical textiles, RFID technology helps to reduce losses, optimise logistics and guarantee the highest hygienic and sterilisation standards.

MRI relies on strong static magnetic fields, so any item containing metal or conductive elements could potentially lead to unwanted effects when placed in an MRI scan device. Such effects ranges from excessive heating and displacement that could harm the patient, to image artefacts (anomalies) that could compromise the diagnosis. Since all RFID transponders contain conductive element and thus fall in this potentially dangerous category, it is then extremely important to accurately test them for MRI compatibility.

The MR conditional label guarantees that a device is suitable for being used in MRI equipment, both in terms of patient safety and diagnosis integrity. This means that a patient wearing a textile fitted with a compliant RFID transponder can be safely scanned in an MR system at 1.5 or 3 Tesla. The MR conditional label does not impose any limitation on the artefact’s size since this does not have a primary safety impact. Nevertheless, an artefact’s presence can impact the medical diagnosis and it is thus important to reduce the artefact caused by the RFID transponder to a minimal size.

According to a spokesperson for RFID system expert Datamars, it can guarantee the maximum quality and safety of its own trademarked UHF RFID LaundryChips product in any healthcare application, MRI included. Datamars has performed extensive studies and validation tests and the information and insight has been used to develop a whitepaper that demonstrates how the highest level of safety and quality for MRI compatibility can be achieved.

In fact, in its ‘whitepaper’ on the subject, the company goes one step further than the MR conditional label by analysing configurations not considered in ASTM standards driving the labelling. As a result, it represents the most comprehensive documentation currently available in the marketplace regarding the use of UHF RFID transponders in MRI environment.

The whitepaper is based on accurate MR validation tests commissioned to MR:Comp GmbH, an accredited ISO certified lab in Germany specialized in testing devices for MRI safety and MRI compatibility. It focuses on worst case usage conditions of UHF RFID tags in MRI environments and compare them to the results obtained for MR Conditional labelling. Patient safety is the first driver of the whitepaper while some considerations are made regarding the possible impact of image artefacts on medical diagnosis.

Unlike other UHF RFID transponders, Datamars’ are not only “neutral” – and thus safe – from a force and torque point of view, but also almost invisible during imaging (artefact size <3.5 mm) such as not to influence the diagnosis. The company has been able to obtain this result by previously making an in-depth analysis of each component used in its UHF LaundryChips  and, when needed, replacing them by a-magnetic elements. In fact, the reduction of the magnetic level of the tag antenna, by using a specially processed antenna wire realised with a patented technology, was the key to reduce the artefact size, ensuring at the same time the maximum quality and safety of the RFID transponder.

The Datamars whitepaper, “RF heating, Force, Torque and Artifact of RFID tag”, can be downloaded free of charge here.