For patients with known active COVID-19 infection and Persons Under Investigation (PUI) for COVID-19, the American College of Radiology (ACR) recommends that practitioners minimize the use of MR except when absolutely necessary, and postpone all non-urgent or non-emergent exams. In some cases, the use of alternative imaging methods such as point of care or portable imaging may be appropriate. As with all imaging, the impact of the results of the imaging must potentially affect imminent clinical management.
The ACR also recommends the following:
MR room cleaning and disinfecting protocols are quite varied and are subject to change with the unique clinical circumstances of that particular site (e.g., availability of PPE, emergent need for immediate access to not yet disinfected MR scanner for non-COVID patient, etc.). General guidelines exist, including cleaning protocol with approved disinfecting agents following a clockwise, linear, top to bottom pattern of cleaning all visible surfaces. However, these will be tempered by local guidelines and policies and especially the specific clinical needs of the patients and site, and are likely to change over time.
MR exams for patients utilizing face masks
Patient / research subject use of face masks while in the MR environment is anticipated to provide some level of protection from COVID-19 for these individuals, MR staff, and subsequent patients and research subjects at that location. MRI facilities are recommended to provide face masks that are known to be MR Safe for patients and research subjects. A recent FDA Safety Communication reports burns to a patient’s face, consistent with the shape of the mask that occurred during a 3T neck exam.
In addition to a bendable metal strip that permits conforming around the nose in many surgical masks, some manufacturer’s masks incorporate metallic fibers and/or metallic nanoparticles in an effort to enhance antimicrobial properties, and these would be expected to pose a risk in MRI.
If there is a metal strip in the surgical mask, in-patients should be fit with known MR Safe masks or respirators, prior to coming to the radiology department. Alternatively, when this is not possible, metallic components from a face mask should be removed prior to, or when necessary, upon the patient's arrival at the MR suite. Tape may be applied across the bridge of the nose section of the mask after removing the metal strip if the site feels that this would be sufficient for adequate transmission control and to maintain the intended function of the mask. If the patient has a tracheostomy, a face mask without metallic component should also be placed over the tracheostomy.
MRI examinations with metal containing masks is strongly discouraged.
Personal Protective Equipment (PPE) worn by MR Technologists and other healthcare personnel entering Zone IV
- Powered air-purifying respirators (PAPR) should not be brought into Zone IV due to the potential risks of adverse interactions with ferromagnetic components of the PAPR system.
- As PPE worn by healthcare personnel are not expected to be exposed to the time varying RF or gradient magnetic fields of the MR imaging environment, the only MR-related safety concern is that of potentially ferromagnetic components of the PPE (e.g., staples, metallic band inserts, etc.) and possible translational and rotational forces that the static magnetic field and the static magnetic field gradient may exert upon them. For such equipment, potential risks can be mitigated by ensuring that no ferromagnetic components are present in the PPE or by removing such components and replacing them with tape (if possible to do so without adversely affecting their intended isolation functionality).