Does the machine use x-rays?
No. There are no x-rays or radiation used during MRI scanning.
Will an MRI scan hurt?
No. The MRI scan is non-invasive and so is painless. For some patients, the doctors may need to use a special contrast dye (gadolinium) to help visualise parts of your body better in which case you would need a cannula (small needle put in the vein of your hand through which the dye can be injected).
All patients are in constant contact with the scanning team via speaker phone so you can let the radiographer undertaking your scan know if you feel uncomfortable. You are also given a buzzer which you can activate at any time to stop the scan and be removed from the scanner.
Who will carry out my MRI scan?
When you arrive at the department you will be met by one of our reception team who will ask you to complete some short paperwork before your scan. The MRI scan itself will be carried out a senior radiographer who is an expert in MR imaging. All of our radiographers have substantive contracts with Imperial College Healthcare NHS Trust and are registered with the Health Professions Council.
The MRI scan will be reported by a Consultant Radiologist who is a specialist in the area being scanned. All of our radiologists hold a substantive NHS Consultant post. We do not outsource our scans to doctors who work outside the UK.
Is the MRI scanner closed?
The MRI scanner is shaped like a round cylindrical tunnel but is open at both ends. You are not shut inside the machine at any time.
What does the MRI scanner sound like?
During the MRI scan the machine is very loud as it makes ‘knocking’ noises during scans and then becomes quiet in between scans. Depending on the type of scan you have you will either receive ear plugs to help reduce the noise or may be able to use the inbuilt stereo system to listen to music during your scan.
How long does an MRI scan take?
MRI scans vary depending on the area of your body that is being scanned but typically last between 20mins and 60mins. You will be informed how long your scan should take at the time of booking.
Do I need to lie still during the MRI scan?
You do need to remain as still as possible during the scan. If there is lots of movement on the images they need to be replanned and taken again which will mean your scan time will be longer. If you are finding it difficult to remain still or have health problems that mean lying in one position is difficult then please let the scanning staff know so that they can help make you as comfortable as possible and let you know in between scans when it is ok to adjust positions.
Do I have to hold my breath during the scans?
No. Although you need to remain as still as possible you should continue to breathe as normal throughout your scan.
Will I be told the results of the scan straightaway?
Your MRI scan will be taken by a fully qualified, senior radiographer however they are not doctors and cannot therefore interpret your scan to determine the result. The images are sent to a Consultant Radiologist who will ensure your scan is reported and returned to your referring doctor no longer than 48 hours after your test.
Will I be alone during my scan?
Although you are usually in the scanning room alone during your test you are in full communication with the radiographer undertaking your scan so that you can talk to each other throughout. If you are particularly anxious about your test it may be possible to have one friend or relative go into the scanning room with you, however they would need to be assessed in advance to ensure it is safe for them to do so (i.e. that they do not have a heart pacemaker or other incompatible equipment).
Is the MRI scan safe?
MRI scans are one of the safest types of imaging because there is no exposure to radiation. However, patients with pacemakers should not undergo an MRI and women should always inform the radiographers if there is any chance they might be pregnant.
Certain electronic devices, including some medical devices, have the potential to interfere with the scan. If you have any type of metal implant or electronic / medical device you should notify the staff before you undergo the scan.
What happens if I am claustrophobic (do not like being in enclosed spaces)?
Some patients who find it difficult to be in enclosed spaces may find undergoing an MRI scan stressful. We are always happy to arrange for you to tour the unit and see the scanner prior to your scan.
During your scan you are in constant contact with the scanning team via a speaker and you are also given a buzzer alarm which you can activate at any time to stop the scan and be taken out from the scanner.
It is possible that you may ask a friend or relative to accompany you into the scanning room (as long as they have undergone an MRI safety check with our staff). For those with severe claustrophobia we recommend notifying your GP in advance about your appointment so that you can be provided with oral sedation. You will need to let us know before your scan so that we can arrange for you to attend the unit with your sedation and take this on site. You will need to bring along a friend or relative to help you get home following the scan because the oral sedation will cause drowsiness.
Can I eat and drink before my MRI scan?
Yes, you can normally eat and drink as normal before your MRI scan. There are a very small number of specialist exams that require you to fast before your scan however if this is relevant you will be informed when making your appointment.
Will I need to undress?
This will depend on the area that is being scanned. If your clothes have zips or metal bra straps that may interfere with the scan then you will be asked to remove these. We will provide you with a hospital gown and changing facilities.
You will be asked to remove all jewellery and metal objects from your person, as well as credit / debit / travel cards and mobile phones. We will provide you with a locked changing room for these items but advise you to leave any valuables at home.
Will I need an injection?
Some patients may require an injection, called contrast, during their MRI scan. This is a special dye that helps show up areas being scanned in more detail. The injection would be given into a small vein into the hand by a radiographer who will then take further images after the injection. Sometimes it is only possible to tell whether you need the injection during the scan but we will always discuss this with you first. There are usually no side-effects from the injection.
What happens during the MRI scan?
After you have been met by our reception team and completed your safety paperwork, a senior radiographer will verify your safety on the scanner, talk you through what will happen during the scan and answer any questions. You will be asked to change (if appropriate) and leave any personal items in one of our lockable changing rooms.
You will be taken to the scanning room and positioned on the MRI scanner. A “coil” or special signal receiver will be placed over the area to be scanned and you will be moved into the middle of the MRI scanner. You will be given a buzzer to alert the radiographer if you want to stop the scan at anytime.
The radiographer will talk to you through an intercom throughout your scan to explain what is happening. It may be necessary to give you a special injection of contrast or dye near the end of your scan. You will be fully advised about this if this applies.
When the scan finishes you will asked to change back into your clothes and collect your personal belongings. You will be given a copy of your scan on CD to take away with you and the results will be sent directly from the Consultant Radiologist who is an expert in the area being scanned to your referring physician.
Are there some people who cannot have MRI scans?
Because the MRI scanner utilises a very powerful magnet, this type of scan is unsuitable for some people. You must let us know in advance if:
- You have a cardiac pacemaker
- You have clips in your head from brain surgery (aneurysm clips)
- You have a cochlear (ear) implant
- You may have a metallic foreign body in your eye from previous trauma or accident
- You have had surgery in the past 8 weeks
- You have a programmable shunt for hydrocephalus (fluid on the brain)
- You may be pregnant or are breast feeding
- You have renal (kidney) problems
In certain instances, we can make arrangements to overcome these difficulties such as using an injection (if clinically necessary) for patients who have kidney problems or undertaking an eye x-ray in advance if you could have metal fragments in your eye. In some circumstances, like with a cardiac pacemaker, we will not be able to undertake the scan.