Simplicity leads to speedier scans

Pictured above from left: Consultant Neuroradiologist Dr Hannah Khirwadka, Clincal Scientist and Magnetic Resonance Physicist Dr Samantha Telfer, Principal Magnetic Resonance Physicist Maria Yanez Lopez and Superintendent Radiographer Barry Spedding

Fewer patients with medical implants such as pacemakers are experiencing delays or last-minute cancellations of Magnetic Resonance Imaging (MRI) scans thanks to simplified procedures.

Radiographers in Swansea Bay hospitals now have safety information on a wide range of commonly used devices at their fingertips, which means more scans can go ahead as planned even if they only find out a patient has a device when they turn up.

It’s vital that precautions are taken with patients who have implants containing a metal component due to the magnetic field generated by the scanner.

Previously, radiographers may have had to delay or cancel the appointment to give them time to track down the make and model of the patient’s device and research if it was safe to proceed.

This proved extremely challenging in cases where devices had been fitted many years ago, in a different part of the UK or abroad.

Maria Yanez Lopez from MRI Physics, the department in charge of advising on scan safety, said new generic policies covering several types of device come into play in those cases where information on implants is not captured before the patient’s appointment.

“We can try to check the records but they may be in a hospital in another part of the UK or abroad,” she said.

“In one case the radiographer was told the building holding the records had burned down so that information had been lost.”

MRI scanners use strong magnetic fields and radio waves to produce detailed images of the inside of the body, which can be used to find out or diagnose what’s wrong, plan treatment and check on how well previous treatments have worked.

Staff must be aware if you have something metallic in your body before carrying out the scan as the magnetic field can cause the implant to heat up, move or malfunction.

They can sometimes adjust the machine’s settings in line with safety procedures for the device and ensure the scan can go ahead.

As medical science advances, so the number of implants with metal components increases. They include pacemakers, small electrical devices used to monitor and control an irregular heartbeat, heart valves, implanted cardiac defibrillators, which use electrical shocks to regulate heartbeats, nerve stimulators to treat long-term pain, cochlear implants which help people hear, artificial joints such as hip and knee replacements, gastric bands for weight loss and stents, which open blocked or narrowed blood vessels.

Implants are designated MR Safe, MR Conditional or MR Unsafe by manufacturers.

So far MRI Physics, in conjunction with Morriston Consultant Neuroradiologist Dr Hannah Khirwadkar, have compiled seven generic implant policies, each covering a particular set of implants, particularly those that are considered to present a low safety risk or where risks are typical across implants of that type.

There are also simplified procedures for MR Conditional implants whose conditions for safe scanning are more complex, such as pacemakers and cochlear implants.

Maria, Principal Magnetic Resonance Physicist, said: “With the generic implant policies, we try to review as many implants as possible within a single category and for some of them we managed to get in touch with NHS Wales procurement, so we have the full list of all the ones bought in NHS Wales within a given period.

“We do literature reviews and look through international databases to check if any adverse effects have been reported when scanning people with these implants.

“Then we make a policy for radiographers to follow which is hopefully quick and easy. It tells them what settings they need for the machine.

“It’s no longer reliant on them having to go off and find out about the make and model.”

Maria said the work is of ever-increasing importance due to the “sea of devices”, many of which are in older people who can require urgent investigation work where there’s no suitable substitute for an MRI.

She explained that in cases where implants are not covered by a generic policy or procedure, the MRI Physics team will provide a bespoke risk assessment, as part of the so called Off Label Policy.

“What we also see a lot of these days are implants where a part has had to be replaced and that part may come from a different manufacturer to the original device. We call these mix-and-match cases,” she said.

“The original manufacturer will then automatically class that device as MR Unsafe and that used to be the end of the line for these patients in terms of getting an MRI scan.

“But now with these procedures we can say what the risk is; low, medium or high and the clinical team will have to weigh up that technical risk against the clinical situation and whether an X-ray or alternative scan could be used.

“Many of these cases can now go ahead to MRI scan, within the framework of our Off Label Policy and informed patient consent.”

Swansea Bay’s MRI Physics team are the only one in Wales and also provide services to other health organisations in Wales, where these advances are also having a positive impact.

The generic implant policies were rolled out across Swansea Bay hospitals in September 2021, followed by the Off-Label Policy around a year ago.

Superintendent Radiographer Barry Spedding said patients are now being scanned quicker.

“For example, we took eight device queries in 48 hours for in patients, which was unprecedented,” he said.

“But due to the efficiency of our cardiac physiology team and being able to follow these simplified procedures, we could scan these patients within 48 hours.

“Historically these patients would have waited quite a bit longer or the clinicians would have been forced to opt for alternative, more invasive procedures which quite often had lower diagnostic accuracy.”