News|Magnetic Resonance Imaging (MRI)| July 15, 2022

Face Masks Unsafe in MRI Machines, Study Shows

New research outlines potential risk to patients who wear certain types of face masks while undergoing an MRI scan

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July 15, 2022 — Certain types offace masksare unsafe for wearing in and aroundMRImachines, according to new research by scientists atCardiff University.

The team tested eight different types of commercially available filtering face piece (FFP3) respirators and found that five contained magnetic components that they regarded as ‘MRI unsafe’.

Many masks containmetal nose stripsor clips to help shape the mask over the nose or metal staples to hold the elastic straps in place. Some masks also have an antimicrobial coating containing typically silver or copper.

When reacting with the huge magnets inside an MRI machine, the metals components can cause a number of complications, including the displacement of the mask, the risk of the metal components flying off, or potentially burning the patient.

There has already been one incident reported in the USA where a patient reported a face mask burn whilst undergoing an MRI scan.

Furthermore, metal components can also cause artefacts to appear on a scan which can, in some cases, make the scans unusable.

在没有任何官方指导佩戴口罩的情况下，研究团队推荐了一种颜色编码系统，以区分“核磁共振安全”口罩和患者当天可能佩戴的口罩。

In their study, the team performed three MRI scans on a 3D printed model of a head and neck which was fitted with eight commercially available FFP3 masks.

The safety of each mask was based on the presence offerromagneticmaterial components, the presence of metallic material, a measurable deflection at the bore of the MRI machine, and a temperature measurement greater than 40°C during testing.

The team found that five of the eight masks contained ferromagnetic components and were thus classified as “MRI unsafe”.

Two masks were deemed “MRI safe” whilst one was deemed “MRI conditional” due to the potential risk of local heating under certain conditions within the MRI machine.

“At present there is no safety documentation surrounding the wearing of face masks in and around an MRI machine so hospital staff are unaware of the potential hazards that masks could pose,” said lead author of the study DrBethany Keenan, fromCardiff University’s School of Engineering.

“It is therefore extremely important to not assume that a mask is safe prior to an MRI examination, and to conduct a safety evaluation to determine which components are made of ferromagnetic metals and which are non-ferromagnetic metal.

“We suggest that where possible, surgical masks should be ordered in a separate colour to distinguish between an ‘MRI safe’ and an ‘MRI unsafe’ surgical mask.”

The study was published in the journalClinical Radiology.