Minimize, reprioritize, and immobilize: practical strategies for managing MR imaging in patients with cochlear and bone conduction implants requiring head wraps

Introduction

More patients undergoing magnetic resonance imaging (MRI) are expected to have magnet-containing cochlear implants and bone-anchored hearing devices as these populations age (Smith-Bindman et al., 2012; Nassiri et al., 2023). Newer generations of these devices are typically MR Conditional up to 3.0 Tesla (T) without additional procedures such as tight head wrapping (Tysome et al., 2019). However, many patients have older MR Conditional devices that require a tight head wrap to safely obtain MR images at 1.5T magnet strength (Crane et al., 2010). Although, studies support the relative safety (Crane et al., 2010; Carlson et al., 2015; Sharon et al., 2016; Pross et al., 2018; Srinivasan et al., 2019; Shew et al., 2019) and efficacy (Sharon et al., 2016; Berry et al., 2024) of MRI in patients with MR Conditional hearing devices, the literature has consistently shown the risks involved with this procedure. Adverse events occur in roughly 15%−20% of MRI scans, even with head wrapping (Srinivasan et al., 2019; Fussell et al., 2021). Complications can include magnet displacement requiring operative intervention [reported in 7 (5%) of 141 scans performed with a head wrap on patients with MR Conditional non-reorienting magnets (Fussell et al., 2021)] and pain causing early termination of the MRI scan [reported rates ranging from 2% to 18% (Carlson et al., 2015; Pross et al., 2018; Srinivasan et al., 2019; Shew et al., 2019; Fussell et al., 2021; Kim et al., 2015)].

Coordinating an MRI scan for a patient with an MR Conditional device involves numerous logistical hurdles. The referring provider should weigh the risks and benefits of MR imaging with the clinical need for the MRI scan. At institutions where members of the radiology team do not perform the head-wrapping themselves, the radiology and otolaryngology teams must coordinate a head wrap for the patient at the time of their MRI scan and, ideally, optimize the MRI protocol for safety and efficacy. Cross-disciplinary communication among otolaryngology, radiology, and referring provider teams is important to overcome these hurdles and reduce adverse events. Yet, few studies have investigated strategies to improve the coordination of MRI scans for these patients.

We sought to develop strategies to improve coordination and patient safety for MR imaging for patients with MR Conditional implants. We conducted a retrospective chart review of MRI scans ordered for patients with MR Conditional devices at our institution. A detailed analysis of these cases provided insights informing the synthesis of practical strategies for improving MR imaging in this patient population.

Materials and methods

After obtaining approval from our institutional review board (IRB00275693), we assembled a consecutive case series at a single tertiary care center of all sequential head wrap requests for adult patients with MR Conditional implantable hearing devices planned to undergo MRI between June 2022 and October 2024. Requests were identified through retrospective review by otolaryngologists in neurotology fellowship training (GSL, AC, JXC, and ZS) of a departmental head wrap scheduling log. Inclusion criteria were MR Conditional implantable hearing devices requiring a head wrap or magnet removal prior to MRI per manufacturer safety guidelines. Requests for MR Conditional devices not requiring head wrap were excluded.

MRI scans for MR Conditional devices were obtained using a static magnetic field strength of 1.5T according to standard procedures approved by the Department of Radiology at our institution and guidance from the device manufacturer's MR safety information. In our standard procedure, the patient has access to a pneumatic squeeze ball they can press during the MRI scan to communicate discomfort, at which time the scan is paused and the otolaryngology team notified to reassess the head wrap and device. MRI scanners from Siemens are used in our hospital. In our institution's workflow, the MRI technologists and otolaryngologists discuss the need for head wrapping for MR Conditional hearing devices prior to scheduling the MRI. Otolaryngology fellows apply a tight head wrap outside the MR room to immobilize the internal magnet just prior to the scan, as previously described (Crane et al., 2010; Sharon et al., 2016; Pross et al., 2018; Figure 1). In brief, at our institution the tight head wrap technique involves obtaining informed consent including discussing risks of pain, device movement, magnet reversal, device extrusion or failure, and potential need for revision surgery; locating the implanted receiver-stimulator magnet via manual palpation and use of an external magnet; covering the magnet site with moldable silicone ear mold putty; immobilizing the putty by tight wraps of two rolls of two inch by five-yard stretchy cohesive bandage; and assessing for patient discomfort and manually adjusting the head wrap tightness as needed to reduce pressure on the forehead.

Patients' electronic medical records were reviewed for information about patient demographics, device type, indication for MR imaging, communication between the neurotology team and referring provider, cancellations, and adverse events including pain and early termination. Pain was assessed by patient report and was documented in the medical record and in routine written communications between the MRI technologist and otolaryngology teams. Early termination was defined as discontinuation of the MRI scan prior to completion of all planned MR sequences. Long-term complications were defined based on patient and device status and device performance at most recent follow-up (minimum 3 months). Additional case details were obtained from the providers who performed the head wraps. A post-hoc case review by a multidisciplinary team of otolaryngologists and neuroradiologists identified patterns and informed the development of practical strategies for improving MR imaging in this patient population. Descriptive statistics were calculated using Microsoft Excel.

Results

Thirty-eight MRI scans were ordered for 31 patients with MR Conditional devices (27 cochlear and four Osia implants). Table 1 summarizes information about patient demographics, device type, MRI indication, and imaging outcomes. Device brands of MRI requests included three Advanced Bionics, 29 Cochlear Ltd., and four Med-El devices. Twenty patients were male (65%), and 11 were female (35%). The mean patient age at device implantation was 49.1 years (SD 19.1 years, range 9–87 years). The mean elapsed time from the implantation date to the scheduled MRI was 10.8 years (SD 7.4 years, range 1–37 years). Sixteen patients (52%) had right-sided devices, nine patients (29%) had left-sided devices, and six patients (19%) had bilateral devices. All three implant manufacturers were represented: 77% Cochlear Ltd., (Macquarie Park, NSW, Australia) 10% Advanced Bionics (Valencia, CA, United States), and 13% MED-EL (Innsbruck, Austria).

Table 1. MRI requests.

Number in parentheses is first MRI scan the patient had.

AB, Advanced Bionics; C, Cochlear Ltd.; CI, cochlear implant; M, MED-EL; L, left; R, right.

Among the 38 MRIs ordered for patients with MR Conditional devices, nine MRIs (24%, i.e., nine out of 38 MRI requests) were canceled after discussions between the otolaryngology team and referring provider clarified that imaging was no longer needed (two orders, 5%; MRI #3 and 5 in Table 1), that a computed tomography (CT) scan would provide a more favorable benefit-to-risk ratio (six orders, 16%; MRI #2, 6, 9, 12, 30, and 37), or that the patient declined after learning about the risks of MRI (one order, 3%; MRI #4). Cases in which the MRI scan was changed to a CT scan included contrast-enhanced abdominal CTs to monitor or characterize focal liver or kidney lesions; CT myelogram to assess for spinal stenosis contributing to neck/back pain; hand CT to evaluate extent of finger osteomyelitis; and head CT to monitor shunted hydrocephalus in a child.

Twenty-nine MRIs (76%) were performed with tight head wraps. Of the 29 scans performed with head wraps, five (17%) resulted in magnet site pain (MRI #11, 19, 24, 27, and 33), which caused early termination of four (14%) MRI scans (MRI #11, 19, 27, and 33). In all cases, magnet site pain resolved within 48 h with no displacement or long-term complication.

Discussion

MRI can be safely and responsibly conducted in patients with MR Conditional otologic devices with proper communication between medical teams. An analysis of our cases points to practical strategies for improving the coordination of MRI in patients with MR Conditional implants, which may also improve patient safety. The strategies are summarized by the mnemonic “MRI”: Minimize unnecessary MR imaging, Reprioritize important sequences first, and Immobilize the internal magnet (Figure 2).

The first strategy is to minimize unnecessary MR imaging and time in the MRI machine. A substantial proportion of MRI orders in this study—eight out of 38 MRI orders (21%)—were canceled following a discussion between the otolaryngology team and the referring provider about the appropriateness of MR imaging and alternative imaging modalities that could provide adequate diagnostic information (omitting one case in which the patient self-decided to cancel the MRI). In several cases (six orders, 16%), this discussion prompted the referring provider to request a CT scan instead. Radiologists have long recognized that a significant minority of scan requests are inappropriate or low-value (Kjelle et al., 2022). Given the safety issues and logistical burden, MRI requests for patients with implanted hearing devices merit a higher degree of scrutiny regarding their appropriateness. Avoiding unnecessary MRI scans reduces the number of MRI-associated adverse events.

Reducing time in the MRI machine can be accomplished by omitting low-yield MRI sequences. For example, some sequences in brain MRI such as echo-planar diffusion-weighted imaging and susceptibility-weighted imaging are often nearly uninterpretable for most of the head due to significant signal drop and distortion artifacts related to the internal magnet (Edmonson et al., 2018). It may be advisable to omit these sequences unless they are critical for the suspected diagnosis (e.g., stroke) and likely to yield sufficiently interpretable data in the region of interest despite artifacts caused by the cochlear implant's magnet. Similarly, fat saturation techniques create substantial distortion artifacts and should be substituted by fat-suppression techniques such as short tau inversion time inversion-recovery (STIR) and robust Dixon techniques (Sharon et al., 2016; Edmonson et al., 2018). Consideration should also be given to using metal artifact reduction techniques to reduce the size/impact of the magnet-related artifacts (Fierens et al., 2021; Nassiri et al., 2024; Cen et al., 2025). A discussion with the referrer and radiologist may be needed to focus a protocol for the clinical question. As an aside, parallel imaging methods—which use calibration scans that are affected by the internal magnet—are routinely employed to accelerate MR sequences, but this acquisition technique produces many artifacts in the setting of a cochlear implant and should be avoided when possible (Kjelle et al., 2022).

Reducing the patient's time in the MRI machine reduces the risk of adverse interactions between the device and the MRI environment. Extended exposure to radiofrequency pulses and gradient fields can lead to device heating, mechanical stress, and prolonged torque on the magnet, which may necessitate early stopping of the scan (Eerkens et al., 2021; Panych and Madore, 2018). If an adverse event has already occurred (e.g., the patient experiences pain), minimizing time in the MRI machine may shorten the duration of the adverse event. Although a prospective study of pain by Pross et al. (2018) did not find a significant association between MRI scan duration and pain, their analysis may have been limited by variability in pain owing to other factors, such as head wrap tightness and patients' psychological expectations.

The second strategy is to reprioritize the scanning of important MRI sequences first. The MRI sequences that are most important for clinical decision-making should be prioritized earlier in the scan in case pain causes early termination of the scan. If the MRI scan is incomplete but contains the essential sequences, then the scan may not need to be repeated. Pain causing early termination of an MRI scan is not uncommon, with reported rates between 2 and 18% (Carlson et al., 2015; Pross et al., 2018; Srinivasan et al., 2019; Shew et al., 2019; Fussell et al., 2021; Kim et al., 2015). In one of our cases (MRI #33), the MRI was aborted mid-way through the scan owing to magnet site pain, prior to completion of the critical sequence (3D T2-weighted) needed for an image-guided neuronavigation bran biopsy procedure, requiring the scan to be repeated during a subsequent visit. In retrospective analysis with the referring provider's team, it was determined that moving the 3D T2-weighted sequence earlier in the protocol would have allowed the incomplete MRI scan to have been usable for surgery and avoided the need for a repeat scan.

The third strategy is to Immobilize the internal magnet. This strategy involves head wrapping when indicated and patient positioning to reduce force and torque on the device's magnet. Head wrap techniques include use of manufacturers' MRI head wrap kits and institutional protocols (Figure 1). Head wraps apply downward compressive force, which increases the mechanical resistance and friction within the device's silicone pocket for the magnet. This force raises the threshold torque required for the magnet to flip out of the pocket's casing. Device manufacturers typically recommend keeping the head aligned with the long axis of the scanner to reduce torque applied on the device magnet from the MRI machine's magnetic fields (Azadarmaki et al., 2014).

Our rate of adverse events is comparable with those reported in the literature (Fierens et al., 2021; Lin et al., 2025; Bestourous et al., 2022). We found a 14% incidence of pain causing early termination of MRI scans despite the application of a tight head wrap. This percentage falls within the range reported in the literature of 2%−18%. At the lower end of this range, Carlson et al. found that two out of 34 (6%) MRI scans involved considerable pain, requiring early termination of the scan (Carlson et al., 2015). A follow-up study by the same group found this adverse event in two out of 101 MRI scans (2%; Fussell et al., 2021). Other studies have reported higher rates of pain causing early termination of MRI scans, including two out of 24 MRI scans (8%) in Shew et al. (2019), five out of 42 scans (12%) in Pross et al. (2018), and five out of 28 scans (18%) in Kim et al. (2015). Pross et al. found variable timing of when pain caused the MRI scan to be stopped, as patients with pain causing early termination of MRI scans spent a mean duration of 17 min (SD 17 min) in the MRI scanner (Pross et al., 2018).

Our retrospective review focused on subjects with MR Conditional hearing devices who underwent head wrap procedures to obtain 1.5T MRI scans with the magnet in place. Alternatively, it is possible to obtain higher strength (i.e., 3T) MRI scans with removal of the cochlear implant magnet, though these cases were not included in our retrospective review. Limitations of the study include limitations inherent to retrospective reviews, single institution data, limited sample size, and post-hoc analysis.

Newer implanted hearing devices have diametric magnets that can freely rotate inside their titanium casing to align with the MRI's magnetic field without pulling on the patient's tissue. Across all the major manufacturers, there are essentially zero reported MRI complications when these new diametric magnets are used (Lin et al., 2025; Bestourous et al., 2022). Devices with these new diametric magnets do not require head wraps for MR imaging. Nevertheless, for those patients with older devices, head wraps for MR imaging will continue to be important. We anticipate that the “MRI” strategies—Minimize unnecessary MR imaging, Reprioritize important sequences first, and Immobilize the internal magnet—will help achieve continued safe MR imaging for these patients.

Conclusion

A quarter of MRI orders were avoidable through pre-imaging review, and among scans performed, magnet site pain and early termination were not infrequent. The mnemonic “MRI” offers a practical framework to reduce these adverse events: Minimize unnecessary MR imaging through multidisciplinary pre-authorization, Reprioritize critical sequences early in case of early termination, and Immobilize the internal magnet to reduce pain and device displacement.

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Footnotes

Edited by: Abdulrahman Hagr, King Saud University, Saudi Arabia

Reviewed by: Guy Fierens, Cochlear Technology Centre Belgium, Belgium

Moayyad Malas, King Saud University, Saudi Arabia