Authors & Affiliations
- Rijo Mathew Choorakuttil, MD, Department of Clinical Radiology, AMMA Center for Diagnosis and Preventive Medicine, Kochi, Kerala, India.
- Praveen K Nirmalan, MPH, Department of Research, Chief Research Mentor, AMMA Center for Diagnosis and Preventive Medicine & AMMA Healthcare Research Gurukul, Kochi, Kerala, India
Corresponding Author: Rijo M Choorakuttil, AMMA Center for Diagnosis and Preventive Medicine Pvt Ltd, Kochi, Kerala, India Pin: 682036. Email: firstname.lastname@example.org
Work Attributed to: Dr Rijo Mathew Choorakuttil, Member (India), QSS Committee of the AOSR
Financial Disclosures & Conflicts of Interest: None of the authors have any financial interests or conflicts of interest to disclose with respect to this study and manuscript.
Aim: To assess current practices on Magnetic Resonance (MR) imaging safety practices among radiologists in India.
Methods: An online survey was administered using Google Forms. The survey included questions on the availability of national legislative or society guidelines on MR safety, the availability, frequency and distribution of training and awareness programs on MR safety, current practices on MR safety including zoning, screening, and shields, and incident reporting systems Responses were anonymized and exported to an MS Excel sheet for further analysis. Frequency distributions of responses were estimated.
Results: Twenty (80%) of the 25 respondents reported availability of MR Safety guidelines at the institutional/hospital level and 24 (96%) of 25 respondents reported availability of guidelines at the radiology department level. Most Radiology departments (n=24, 96%) use a checklist or protocol for pre-MRI assessments. Twenty-one (84%) of the 25 respondents reported that there was site restriction or zoning for their MR services. Twenty (80%) respondents reported the availability of a list of MRI safe items at the departmental level and provided this list to patients before MR imaging. Twenty-one (84%) respondents reported that there was a regular screening of MR staff, however, screening of non-MRI personnel was reported by only 15 (60%) respondents. Just over half (n=13, 52%) of respondents reported the presence of an MR critical incident reporting system in their department.
Conclusions: The results of our survey highlight the need to improve several aspects of MR safety including the development of specific guidelines and protocols for MR safety, development and utilization of critical incident reporting systems and increased awareness and regular training for radiologists, radiographers, and MR technologists.
Key Words: Magnetic Resonance Imaging, Safety, Screening, Zoning
Magnetic Resonance Imaging (MRI), which provides opportunities for exceptional soft-tissue contrast and non-ionizing radiation exposure, is increasingly used in healthcare diagnostics.1 Rapid evolution and application of MR technology for different clinical conditions often lead to the identification of new safety issues. The three electromagnetic fields in MRI- the static magnetic field, the time-varying gradient magnetic field, and the radio-frequency field- can lead to different safety risks.2-5 Adverse outcomes associated with exposure to these electromagnetic fields may include vertigo, nausea, hazards caused by projectile forces, biomedical implant and device risk, translational forces on ferromagnetic objects, peripheral nerve stimulation, heat deposition and acoustic noise.2,6-11 Safety-related incidents can increase as MR based diagnostics becomes more widely used and more scanners with higher capabilities are installed.4 Incident-reporting systems are essential to report and learn from incidents, understand their causes, determine actions to prevent future incidents, minimize avoidable human suffering and save hospital and litigation costs.4,12-15 However, the gross underreporting of MR safety incidents indicate the need for a more robust system. 16-19 It is important that MR technologists, radiographers and radiologists are aware of the rapidly evolving changes in MR safety to optimize safety practices. The Asia Oceania countries are diverse socioeconomically, culturally, and geographically, and an understanding of the local situation in each country is needed to promote and implement optimal safety practices. The Asia Oceania Society of Radiology (AOSR) and its Quality Safety Standards (QSS) Committee designed a baseline to further build the promotion of MRI safety awareness, educational videos or teaching materials in the Asia Oceania region. In this manuscript, we present the India specific results of this AOSR-QSS Survey on MR Safety Practices.
The survey questions and response patterns were developed by members of the Quality and Safety Standards (QSS) Committee of AOSR. The questions were based on the individual experience of committee members and the final questions were selected based on consensus. The final questionnaire developed in English was converted to a Google Form (available online at https://forms.gle/rkCJ1L18rGe4zCb87 ) that enabled online administration of the questionnaire to radiologists in India. The survey included questions on the availability of national legislative or society guidelines on MR safety, the availability, frequency and distribution of training and awareness programs on MR safety, current practices on MR safety including zoning, screening, and shields, and incident reporting systems. Respondents were asked to upload relevant legislative or societal guidelines either as a document attached to the Google Form or provide a link to the digital version of the document in the Google Form. The link to the questionnaire with a brief description of the purpose of the survey was e-mailed to the IRIA central office to circulate to all members of IRIA. The link to the survey and the details of the survey were also posted in several social media groups of radiologists. A reminder about the survey was disseminated 15 days after the initial notice. The responses to the online survey were anonymized and were linked from the Google Form to a Google spreadsheet for further analysis. The online survey was open from October 1, 2021, to November 1, 2021, and all responses to the survey were considered. The first response from an institute was considered if there were more than one respondent from the same institute.
The survey elicited 25 unique institutional responses from India. Respondents reported on the lack of documented national legislation on MRI and MR Safety and national radiology society guidelines on MR safety. Twenty (80%) of the 25 respondents reported that MR Safety guidelines were available at the institutional/hospital level and 24 (96%) of 25 respondents reported the availability of MR safety guidelines at the radiology department level. Most Radiology departments (n=24, 96%) use a checklist or protocol for pre-MRI assessments.
Twenty-one (84%) of the 25 respondents reported that there was site restriction or zoning for their MR services. Twenty (80%) respondents reported the availability of a list of MRI safe items at the departmental level and provided this list to patients before MR imaging. Twenty-one (84%) respondents reported that there was a regular screening of MR staff, however, screening of non-MRI personnel was reported by only 15 (60%) respondents. Most (93%) of the 15 respondent units where screening of non-MRI personnel was done used ferromagnetic detectors for screening. Twenty (80%) of respondents reported that they screened the persons accompanying the patient for MRI and 17 (89%) of these 20 respondents reported using ferromagnetic detectors for the screening. Table-1 presents the details of training on MR safety for staff at the radiology department and medical staff outside of the radiology department. Just over half (n=13, 52%) of respondents reported the presence of an MR critical incident reporting system in their department.
Patient safety involves all aspects of preventive, diagnostic, therapeutic and interventional healthcare. Patient safety, within the specific context of MR imaging, involves interactions between human factors, the instrumentation and technology used, the external environment and the robustness of the systems used to identify and report critical incidents. The results of our survey highlight the need to develop specific guidelines and protocols for MR safety, utilize critical incident reporting systems and increase awareness and regular training for radiologists, radiographers, and MR technologists.
Adverse events associated with static magnetic fields include interactions with human tissue and with equipment (projectiles, implant malfunction or movement, malfunction or movement of monitoring devices).4 Issues related to specific absorption rate (SAR), heating of the implant and tissues and implant interference effects are some of the specific risks associated with radiofrequency fields. 4,20 Peripheral nerve stimulation, acoustic noise, and interference with implants or monitoring devices are some of the risks associated with time-varying gradients.4,20
An estimated 10 to 20% of patients that undergo an MRI have implanted medical devices.21 Clinical MR scanners utilize a superconducting magnet and a static magnetic field is always present. These implants and devices including ferromagnetic objects are subjected to translational and rotational forces in the static magnetic field and can lead to a projectile effect.7 Patient safety can be improved by understanding the composition of these objects and their behaviour in the magnetic field environment of MRI. The American Society of Testing and Materials (ASTM) International Committee has identified three MRI safety categories: MR Safe, MR Conditional and MR Unsafe, and labels each with an associated icon.22 MRI system vendors provide spatial gradient magnetic field (SGMF) maps for each scanner, which plots the change of the static magnetic field over distance and demonstrates the point of the maximum spatial gradient. The SGMF maps will differ between scanners and the MRI technologist must interpret different SGMF map formats as appropriate to determine implant safety.22,23 A rotational force or torque that forces realignment of objects with the direction of the main magnetic field can occur on ferromagnetic objects when patients are brought into the scanning room.24 The combination of translational and rotational forces may lead to implant dislodgement, mechanical failure in active implants, movement of metallic devices and foreign bodies and cause organ damage or death.25 The MRI technologist must obtain the most relevant information regarding the health of the patient and the presence and safety labels of any device or implant and apply these conditions to a specific scanner in the workplace by understanding the vendor SGMF maps.25 Acute sensory effects that can be associated with movement through the static magnetic field are related to the movement induced voltages and are of particular concern as 7T systems are introduced into the clinical setting.11,26,27
Thermal injury accounted for 59% of the FDA’s MAUDE MRI adverse event database.28 Burns are mostly caused by the introduction of electrically conductive materials into the scanner, direct contact with RF coils, proximity burns due to contact with the scanner bore or electrical loops formed by the patient’s body.28 Newer MRI burn hazards can occur with technological advances in other industries. For example, clothing manufactured with invisible silver-embedded microfibres can produce electromagnetic eddy currents and highlight the importance of changing all patients into facility-provided gowns.29 An MRI face mask burn was reported in 2020 and reinforces the need to remain aware and vigilant during the patient screening and preparation processes especially as face masks are mandated during the COVID-19 pandemic.30 Transdermal patches may have a metallic backing and the United Kingdom (UK) Medicines and Healthcare Products Regulatory Agency (MHRA) recommends the removal of medicinal patches that may contain metal if removal will not compromise patient treatment.31
MRI technologists must adhere to best practices by changing the patient to the facility provided safe clothes, using pads to avoid skin-to-skin and skin-to-bore contact, checking the position of the limbs of the patient, ensuring the patient’s skin is not in contact with leads or monitors and use a heat sink over tattoos situated within the RF coil. 25 The technologist must consider the patient’s age, thermoregulatory system and underlying health conditions that compromise the ability of the patient to disperse or tolerate heat change. MRI technologists must change environmental and scanning parameters to minimize patient heating and understand why specific scanner field strengths, RF coils, SAR limitations and lead positions are defined for various MR Conditional implants and devices and the adverse impact of not adhering to these conditions.25 The MRI technologist must correctly fit earplugs and check that the patient does this, and ensure that appropriate hearing protection is provided to, and worn by, anyone remaining in the scanner room during the examination.25
The reporting of critical incidents is important from the perspective of magnitude and provides a good learning opportunity to improve safety standards and processes. Globally, critical incident reporting systems are grossly underutilized.16-19 Kihlberg, et al, reported that only 38% of critical incidents were reported and that several of the unreported incidents could have turned catastrophic.17 They also reported a negative correlation between the number of annual incidents (per scanner) and staff MR knowledge and the number of MR physicists per scanner.17 A major finding from their study was that only half of the study sites had implemented the EU directives on MR safety.17 Hansson et al, observed that 16% of MR safety incidents had the highest severity or worst case scenario score, that severe adverse events still exist despite safety protocols, critical incidents are poorly shared within the team and are preventable.32 Hansson et al reported that the confidence in internal communication or local reporting systems might be much greater than the true usefulness of such routines and recommended more careful design of critical incident reporting systems to facilitate the use and sharing of information.32 Jones et al described these challenges in their paper that explored the challenges to establishing national critical incident reporting systems.33 Blankholm and Hansson have also reported a high rate of underreporting of MR safety incidents with 53% of MR professionals reporting involvement in an MR-related incident that was reported, and 25% reporting involvement in an incident that was not reported.19
Several specific and interlinked actions targeted at specific groups are necessary to improve MR safety. These include, but are not limited to, the identification and demarcation of specific risk zones, design of specific educational programs for professionals working with MRI, clear MR safety procedures including screening forms and protocols, and rigorous but easily manageable incident-reporting systems focused on prevention and learning from mistakes.19
The survey provides some baseline information to develop a roadmap for MR safety initiatives in India and highlights the potential actions that the QSS committee and AOSR, in collaboration with the Indian Radiological and Imaging Association (IRIA) can initiate to further improve MR safety standards in India. These include the development of specific guidelines and protocols, the development of a critical incident reporting system and the development of specific teaching and training modules on MR Safety and awareness, and the development of educational materials and safety protocols on MR safety for the patients and attendants. The survey provides a benchmark to monitor and evaluate the progress of these initiatives. Additionally, a specific database of MR practitioners in India can be developed to ensure a targeted approach for MR safety measures. The low number of respondents to the survey may be considered a limitation, however, the lack of a specific MR practitioner database precluded a targeted approach for the survey.
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- Hartwig V, Giovannetti G, Vanello N, Lombardi M, Landini L, Simi S. Biological effects and safety in magnetic resonance imaging: a review. Int J Environ Res Public Health. 2009 Jun;6(6):1778-98. doi: 10.3390/ijerph6061778. Epub 2009 Jun 10. PMID: 19578460; PMCID: PMC2705217.
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- Tsai L, Grant A, Mortele K, Kung JW, Smith MP. A practical guide to MR imaging safety: What radiologists need to know. Radiographics 2015; 35: 1722–37.
- Chakeres DW, de Vocht F. Static magnetic field effects on human subjects related to magnetic resonance imaging systems. Prog Biophys Mol Biol. 2005;87(2–3):255–265.
- Shellock FG, Crues JV. MR procedures: biologic effects, safety, and patient care. Radiology. 2004;232(3):635–652.
- Glover PM. Magnetic field-induced Vertigo in the MRI environment. Curr Radiol Rep. 2015;3(29):1–7
- Schenck JF. Safety of strong, static magnetic fields. J Magn Reson Imaging. 2000;12(1):2–19.
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- Panych LP, Madore B. The physics of MRI safety. J Magn Reson Imaging. 2018;47(1):28–43
- Jones DN, Benveniste KA, Schultz TJ, Mandel CJ, Runciman WB. Establishing national medical imaging incident reporting systems: issues and challenges. J Am Coll Radiol. 2010;7(8):582–592.
- Soop M, Fryksmark U, Koster M, Haglund B (2009) The incidence of adverse events in Swedish hospitals: a retrospective medical record review study. Int J Qual Health Care 21(4):285–291
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Table-1: Frequency of training on MR safety at the 25 respondent units
|Frequency of MR Safety |
|Staff at Radiology Department||Medical Staff outside Radiology Department|
|No training||3 (12%)||10 (40%)|
|Once a year||6 (24%)||8 (32%)|
|Twice a year||1 (4%)||0 (0%)|
|More than twice a year||2 (8%)||2 (8%)|
|Once every 2 years||3 (12%)||2 (8%)|
|Every new radiology staff/non-radiology physician is trained||10 (40%)||3 (12%)|