Synopsis

Keywords: Transferable skills: Safety, Transferable skills: Project management, Transferable skills: Value

Magnetic Resonance Imaging (MRI) is now a standard technology in many radiology departments and essential for modern patient care.
It is being used more often in the care of emergency patients, including in trauma, ranging from minor injuries to major trauma. This brings its own risks: in particular patient and staff safety related to the magnetic field.
This talk will discuss:

1. clincal reasons to install MRI in the emergency department
2. matters to consider when deciding where to place an MRI scanner
3. staffing the scanner
4. safety including design, access, patient and staff screening, and training non-radiology staff
5. financial considerations
6. future developments

Introduction

Magnetic resonance imaging (MRI) is now standard of care for many patients. It complements other radiological techniques, provides information not otherwise available, and can assist with more certain diagnoses and patient management.

Having MRI in the emergency department (ED) can enhance patient care and workflow but also increases the potentially fatal risks unique to MRI. This needs a multifactorial approach to maintain safe operations.
It remains the most expensive radiology modality and the costs need to be considered when establishing MRI in ED.

This lecture will discuss the matters that should be considered when setting up MRI in the ED.

Clinical matters

Ready access to MRI can assist with timely patient care.

A dedicated MRI in ED means
· not competing with other patients for access
· no need to transport unstable patients out of ED
· easier monitoring of unstable patients
· faster diagnosis and expedited care
· potentially less ionising radiation
· greater ability to do the most appropriate investigation

MRI complements other radiology technologies and each has it pros and cons. As MRI sequences are much longer than CT scans, MRI copes less well with patients who are unable to stay still for the entire time required to acquire each sequence.

Easier access to MRI can result in unnecessary investigations which adds to costs, delays access for time-critical imaging and delays the reporting of critical studies. Ensuring all investigations are clinically justified and have a real potential to affect patient care is important. Over-imaging is not in anyone’s interests.

A local imaging policy regarding who gets an ED MRI and who has outpatient MRI will assist operations, i.e. will it operate as a ‘one stop shop’ for everyone including minor trauma; just scan patients with time-critical major trauma; or will it be used for somewhere in between.

Safety matters: ED staff, equipment and environment

The scanner is always on. Non-MRI staff do not understand this or the serious, potentially fatal, risks.

Safety risks are greater because of the large number of staff who are not MRI-aware. There are large numbers of staff in ED, including locums and agency staff. In addition staff come from all parts of the hospital to look after ED patients.

Safety risk mitigation strategies need to be multifactorial and include:
· a safety-first culture
· MRI suite design and access restriction
· a physical barrier, such as a tape, across the entrance
· mandatory staff training and retraining
· strict, enforced screening protocols
· recognition of the MRI radiographers' commanding role
· practising code blue responses
· extreme radiographer vigilance

Records of staff safety training should be kept for audit and compliance with safety requirements.

The MRI suite must retain all the safety design features found in other MRI suites. The four zones are needed. Namely:
· Zone 1 general access: no restrictions.
· Zone 2 trolley bay, screening and waiting area: this is a restricted access area and should have sufficient privacy to complete safety checks including looking for items on the patient or the trolley.
· Zone 3 control room: highly restricted access for MRI staff and screened personnel only.
· Zone 4 the scanner room: highest risk and tightly controlled access.

All restricted access zones should be swipe card access with this only given to MRI staff. ED staff should not have unrestricted access. The list of staff with swipe card access must be reviewed monthly and those who no longer need access have this stopped.

A dockable table is much safer for ED MRI: the table can be taken to the patient and the patient transferred to it well away from the riskier MRI environment. This is similar to a patient retrieval in the field. A dockable table will also assist in the rapid removal of a patient from the scanner room in the event of an emergency and reduce the risk of MRI-incompatible equipment being taken into the scanner room.

The fringe field extends beyond the 5 Gauss line. This needs to be considered as it can affect the operation of other equipment. This can affect adjacent areas and the floors above and below.

Radiology rooms are inherently less safe than the resuscitation bay. MRI is the least safe of all as it is much harder to monitor the patient and the magnetic field is dangerous if rigorous safety protocols are not enforced. Scanning protocols need to be short to minimise the time in MRI. For critically ill and unstable patients these need to be less than ten minutes of scanning time. All emergency care, including code blue, must take place outside the scanner room. There needs to be a well-defined, widely known and practised protocol for managing a code blue.

MRI safety material provided by ISMRM and the British Institute of Radiology are useful for education and training.

Renal function should be known if gadolinium-containing contrast media are to be used.

Technical and financial matters

The type of scanner and coils need to suit the expected work. A 1.5T MRI is a good balance of safety, costs and image quality. The MRI needs to be able to do fast sequences and have a wide bore. This may require specific software.

The site selected needs to be large enough to have not just the MRI scanner, control room and computer room, it also needs to have a trolley bay waiting area where access is restricted and safety checks can be completed. The location needs to have the right electricity supply, cryogen safety, piped medical gasses and not put other equipment at risk. MRIs are noisy and this may affect the location chosen. As electromagnetic fields can interfere with the scanner, the site needs to be away from the CT scanner, trains, trams and similar infrastructure.

MRI-safe ventilators, anaesthetic machines and pumps are needed with consideration given to making all ED kit MRI-safe. Patient trolleys, wheelchairs and splints need to be chosen with MRI safety in mind or left outside the MRI suite.

Piped medical gasses will need to be installed.

MRIs are expensive, with a 1.5T MRI typically costing AUD 1 000 000 for the machine. The installation costs are greater and in all can cost AUD 16 000 000 to AUD 19 000 000. The decision to install MRI needs to be financially sound. Costs include the machine, coils, building the Faraday cage, rooms, installing the utilities and the costs of furnishings, consumables, maintenance and staff. Will the workload justify the cost? This is particularly important where budgets are constrained. A comprehensive service contract will help finances and minimise downtime.

All accreditation standards need to be met and many of these will have safety aspects.

Radiologist and radiographer matters

The radiographers’ MRI safety role is critical to the safe operation of the scanner. There must be enough fully MRI-trained radiographers to be able to cover the roster, leave and unplanned absences. These radiographers should rotate from the main radiology department MRI scanner to ensure their skills and training are current. The training records need to be kept for audit purposes.

The radiographers’ priority task is safety: of patients and staff. At all times, there must be at least two MRI-trained radiographers in the MRI area. Dedicated MRI nurses and clerical staff will make the environment safer.

Radiographers face particular challenges in safety screening patients who are in pain, obtunded, confused, distressed, medication-affected or do not speak the same language. This is one of the biggest risks associated with MRI in the ED. Novel solutions are needed and include:
· talking to next of kin
· telephone interpreter
· review of all earlier imaging (CT and X-rays)
· two-plane whole body CT scout images with X-rays of anything suspicious
· checking the patient, the trolley and any other equipment for potentially unsafe items.
· a handheld magnet to find hidden ferromagnetic items.

Asking key questions more than once will minimise the risk of MRI-incompatible devices being forgotten.

As radiographers are responsible for screening staff it is sensible to do this every time a non-MRI staff member comes to MRI. Careful screening of any clinicians who need to be in the scanner room to manage unstable patients during the image acquisition is essential.

All staff must accept that no MRI is so urgent that a full safety check cannot happen.

The perceived need for speed can create tension with doing safety checks and this needs to be managed by the radiographer with radiologist back up. Having experienced radiographers helps.

The radiographer has the final say on safety in MRI.

As safety checks have to be managed without the flexibility available in outpatient scanning, the MRI should only be operated in normal SAR mode as this minimises risks with tattoos, stents and other implants where there are safety restrictions on the way the MRI can be used.

Radiographer safety duties should include regular, thorough inspections of the facility looking for and removing items that should not be there.

To minimise the time unstable patients spend in the MRI bespoke protocols are needed to answer specific clinical questions, preferably in under ten minutes of scanning time. Radiologists need to select the most useful two or three sequences, e.g. diffusion and susceptibility-weighted sequences for head trauma and whole spine sagittal STIR and T2-weighted sequences with axial T2-weighted sequences through the levels of concern. They should complement any other imaging performed.

Protocols for minor trauma should be reduced to the minimum to make the diagnosis so that the machine is available when needed for time-critical imaging.

Consideration should be given to replacing CT when appropriate, especially in those patients where ionising radiation poses greater risks, e.g. paediatrics and in pregnancy.

Radiologists should be onsite to support the radiographers, manage referrers’ expectations, provide radiology advice, review images when the patient is in the scanner, and review and report the scans urgently.

Radiologists have an important role in educating the ED doctors about the appropriate use of MRI, vetting referrals and redirecting to MRI or CT when a different investigation is more appropriate. The radiologists’ triage role includes prioritisation of referrals for MRI. Triage will include non-trauma ED patients such as stroke.

Understanding the effect of human factors (science) on radiographers and radiologists is important for the safe operation of the MRI and safe reporting of the images: in particular the effects of fatigue, workload, interruptions, back-of-clock operating, situational awareness and stressors. Taking steps to mitigate these risks will enhance patient and operational safety.

The future

Faster sequences are being developed and these will assist in minimising time in the MRI scanner.

Lower field scanners with minimal helium requirements and no quench pipe are entering the market.

Mobile MRI is in development but not yet widely in use. Design, safety and image quality will determine how this could be used. Diagnostic utility must be maintained or there is a risk of false negative and false positive reports.

Conclusion

MRI has a role in ED that is evolving and increasing. Establishing MRI is feasible with the right safety precautions.

CT remains the workhorse technology for its speed, ease of monitoring patients, fewer contraindications and low risk of immediately life threatening hazards.

Each department has to assess local factors to work out what best meets their needs.

To establish ED MRI there should be consideration of:

· being able to operate with safety as the top priority
· having the right space
· cost effectiveness
· an understanding that ED MRI protocols are not full protocols
· the MRI will be used for much more than trauma
· having suitably trained and skilled radiographers and radiologists to work in the ED MRI.

If these criteria cannot be met consider direct access to the MRI scanner in a radiology department next door as a safer compromise.