This month NHS Fife was delighted to receive delivery of a new MRI scanner which is destined for the Diagnostic and Imaging department at the Queen Margaret Hospital in Dunfermline. This is to replace the previous scanner that has been operational for the last 12 years. Delve, thought we’d dig deeper and find out why the new scanner was needed and indeed, what MRI scanners actually do…
Scanner arrival at Queen Margaret Hospital's Diagnostic and Imaging centre
Our interest piqued by the arrival of this large piece of kit, Delve decided to find out a bit more about the world of MRI scanning by speaking to David Pirie, Lead Radiographer
Our Replacement programme
The replacement programme, which has taken approximately three months to complete, includes the removal of the old scanner; replacing the Radio Frequency (RF) cage which shields the MRI room from external interference which can affect the scans; replacing existing electrical and mechanical appliances required to support the safe use of the scanner, and the installation of the new scanner. The new scanner is one of the most modern on the market, replicating the scanner currently on the Victoria Hospital site.
We’ve all heard the term MRI, but who actually knows what it stands for?
MRI is an acronym for Magnetic Resonance Imaging. An MRI scanner uses a strong magnetic field and radio waves to create computer images of tissues, organs and structures inside the body. Often, after a visit to our GP or outpatient departments, the health professional will need more information than we as patients can provide about our symptoms verbally. This is where the MRI scanner comes in.
It scans the body to create images of various parts to help with the diagnosis of many conditions. In Fife, we perform over 14,000 MRI examinations per year, providing valuable information to our primary care (that’s your doctor) and acute care teams (hospital teams, in other words) to allow the planning of the correct treatment for patients.
What makes this scanner better than the previous model?
This scanner has a wider and shorter bore which is more beneficial for claustrophobic patients. The exams can be done faster and there are a number of new scan sequences that radiographers were not able to perform on the old scanner. It will also allow for a more standardised customer experience.
Patients that now attend either of the sites in Fife for their MRI examinations will have a similar experience and the image quality will be of a very high standard. Although some MRI examinations can still take up to 60 mins to complete, the majority are now done and dusted in between 15 and 30 minutes.
How does MRI work?
Most of the body is made up of water molecules, which consist of hydrogen and oxygen atoms. At the centre of each hydrogen atom is an even smaller particle called a proton, which are like tiny magnets and are very sensitive to magnetic fields. When you are placed in the scanner, the protons align themselves to the powerful magnetic field of the scanner.
Short bursts of radiofrequency (RF) pulses excite these protons spinning them out of alignment. When the RF pulse is switched off, the protons realign along the magnetic field (relaxation) emitting signals which are picked up by receiver coils.
These signals provide information about the exact location of the protons in the body.
Changing the scan parameters allows the ability to distinguish between various types of the body as different tissue types have different relaxation speeds producing distinct signals.
These different signals are combined and using powerful computers this allows the machine to create detailed images of the inside of the body.
Can any part of the body be scanned?
It can, and taking scans of different parts of the body, will provide information on those specific areas. The specialities that the team in Fife most commonly work on are as follows:
Imaging of the soft tissue neck to provide information on swellings/lumps, parotid and salivary glands. MRI is not used that often in the chest as other Radiology modalities are better such as CT, however, MRI can be used to assist other scans to sometimes add extra information for better diagnosis.
Imaging of the musculoskeletal system, which are the bones and joints - knee, hips, shoulder, wrist, hand, ankle, feet etc.
Can MRI scanning be used to help diagnose cancer?
The Fife MRI Team is also central to the planning of treatment for many cancers including, prostate, breast and rectal. This is known medically as the Oncology discipline and would cover many parts of the body to detect cancer. Once a cancer is diagnosed, sometimes by other modalities used in Radiology
for example by this we mean for example by using X-rays, CT scanning, ultrasound scanning) MRI can also be used to stage the disease. This would be to see the extent on how far the disease has spread which is really important to help doctors in planning the best treatment for patients.
How would you prepare for an MRI scan?
Some examinations may require you to fast for a few hours prior to your appointment. Anyone who’s had this type of scan will recall being asked to remove all valuables but may not realise why. In fact, it is because ferrous objects will be attracted by the strong magnetic field and there is potential for serious injury.
The same is true of bank cards or cards with magnetic strips, electronic devices such as mobile phones can be damaged by the strong magnetic fields of the laser – a good reason not to take your bank cards!
Don’t be tempted to wear your tinted contact lenses to a scan
In addition, some metals such as those used in jewellery, are at risk of heating during an MRI scan and can cause serious burns so the teams asks that all body piercings are removed prior to attending. As some make-up can contain iron the team ensures that no make-up is worn during scanning procedures. This is of course to protect patient safety and is paramount. What you may not have realised is that tinted contact lenses also need to be removed prior to scanning as these can also contain iron oxide which again is a hazard during MRI.
Did you know about hot tattoos?
Yes, it’s true. There is a potential heating effect to tattooed areas of the body. Staff are, of course, aware of this so can alert the operator if they feel that the patient is experiencing any discomfort. In addition, all patients are provided with an alarm squeeze ball which is used to contact the staff during the scan if they are having any difficulties – with hot tattoos or otherwise.
What should I wear to an MRI scanning appointment?
This doesn’t matter so much. All patients are required to change into a hospital gown as clothing may contain metal parts such as zips
which can distort the scan image or can cause a similar heating up effect as experienced in the case of tattoos.
Did you know that MRI scan noise has been compared to that of a jackhammer?
The noise generated during an MRI scan is often compared to that of jackhammers: loud clanking, banging and industrial noise. Though alarming, these noises are completely normal! They are created when the electric current in the scanner coils is being switch on and off. Sometimes the noises generated do in fact exceed the specified guidelines, so all patients are given earplugs and ear defenders to wear during the scan.
The Radiographers will then communicate with patients at certain times throughout the scan, either by using headphones or the use of speakers. There is also an intercom to allow two-way communication. This, however, is not used when the scanner is noisy so that patients can contact the Radiographer in an emergency by squeezing the emergency squeeze ball to attract the Radiographers attention.
How long does an MRI scan take?
MRI scanners are more advanced now than when first developed and are capable of undertaking much faster scans. MRI examinations are an actual combination of different scans so to complete say a routine brain examination, there may be four different types of scan. Each scan is planned to see the anatomy differently.
There will be a change in the type of noise emitted when different scans are run. Although some specialised examinations can still take up to an hour to complete, the majority in Fife are now completed in 15-30 minutes. Some examinations can be done in even less than 15 minutes.
I’ve heard that some procedures involve the injection of a dye into the body?
Some examinations in MRI require you to have an injection of dye. This dye is called a contrast agent and is administered through a cannula (a portal) which is inserted into a vein in your arm. This contrast agent is a clear fluid and contains the metal element Gadolinium. Gadolinium is a paramagnetic substance which is temporarily magnetised within a magnetic field (MRI scanner).
This then changes the properties of the tissues which can provide further information during scanning. Sometimes it is used to see the blood flow through the body much easier, diagnosing certain conditions such as inflammation and infection as well as providing really important information when looking at tumours.
Diagnostic imaging is a critical component of modern and effective healthcare, with more than 14,000 MRI scans carried out in Fife last year alone. With the demand for MRI increasing year-on-year, it is essential that we continue to have the capacity to meet this demand.
It's clear then that the replacement of the MRI scanner at Queen Margaret Hospital will provide a number of benefits for patients across Fife. It comes at a time when Diagnostic imaging, a critical component of modern and effective healthcare, in in high demand, with more than 14,000 MRI scans carried out in Fife last year alone.
With this demand increasing year-on-year, the new machine will more than meet the demand for scanning procedures locally and minimise diagnostic waiting times for patients in Fife. This concludes our look at the world of MRI scanning. Thanks to David Pirie, Lead Radiographer and the Radiology team for these interesting insights in to MRI scanning.