Questions we’re often asked about having an MRI scan
Why is the scanner noisy?
Due to the nature of MRI, (the scanners are made up of various elements, part of the scanner contains coil windings) the coil windings within the scanner vibrate as electric current pulses through them which in turn causes them to knock and bang against the internal housing, leading to the noises you hear which will vary with different types of scans performed.
Many people put tunes to the noises produced, and they are often quite rhythmical and hypnotic like the clattering of a train.
How loud is it?
Within the scan room the noises produced are normally around 100dB, sometime higher, which can be equivalent to those experienced in a rock concert.
Can you reduce the noise?
The noise produced cannot be adjusted although there are increasing developments by scanner manufacturers which allow limited adjustment of noise, and in some cases this can be as low as a vacuum cleaner. This is dependent on what type of scanner is available at the location for your scan.
However, due to the nature of the noise levels experienced we do provide ear protection that must be used, and this will be explained and provided by our staff as part of your scan. Dependent on local scanning equipment this may be earplugs, ear defenders/headphones, or a combination of both. Please follow advice provided by our scanning teams, it is for your comfort and safety.
In some circumstances music can also be played over the ear protection to help provide some better background to the scan and help pass the time quicker.
Will someone be able to talk to me, and how frequently?
The member of staff performing the scan will be able to communicate with you over an intercom between scans throughout the procedure. They can see you at all times and a call bell will also be provided should you require their attention during a scan.
Sometimes breathing instructions are required, you may hear these instructions via an automated voice of the scanner, this does not mean our staff have left you alone, they are still behind the window and in easy access should you need them.
Can I have a break between the scans?
An MRI examination is made up of a series of scans (also termed sequences) which can each last between 1-5minutes depending on what is being performed. Whilst a member of staff can talk to you between each scan, whilst we are performing a single body area it is best to remain in the same position throughout so as not to require resetting and add delay to the examination. However, if at any point you do need to come out this is possible.
When scanning more than one body part which will take longer, there are often natural breaks when equipment may need to be changed or repositioned before continuing. At these points you will be bought out of the scanner and have an opportunity to take a breather or have a wriggle as required.
Your comfort is important and helps us achieve the best possible images so please discuss this with the scanning team on the day. We have plenty of pads and techniques which may help.
Can I bring someone into the room with me?
For our younger patients (<16) or those more nervous of the scan it may be that someone accompanying you can remain in the scan room with you whilst your scan is being performed. This can only be one person and is dependent on them also being safe to enter the magnetic field and remain in the room – they will be asked to complete a Safety Screening Questionnaire the same as you are for your scan.
Does the scanner stay as it is?
The scanner itself is a tunnel shaped machine, open at both ends, and remains open throughout. The only piece of equipment that will be possibly placed on you and touching is what we term a coil, which is essentially the piece of equipment that acts as an aerial and receives the signal to help construct the images. The scan table may move into different positions during the examination but the member of staff performing the scan will advise when this happens.
Do I have to go all the way in?
Whichever area of the body being scanned needs to be within the centre of the scanner in order for us to acquire the necessary images.
As a general rule any areas from the waist down are scanned entering the scanner feet first, and those waist upwards are scanned entering head first.
Will it go dark?
The room lights will remain on for the entirety of the examination, plus there are lights within the bore of the scanner which also remain on the whole time to keep the space light and bright. There is also a constant flow of air down the bore of the magnet to help cool and calm.
Can you scan with the door open?
Unfortunately the scan room door does need to remain closed for the duration of the scan in order to prevent interference with the quality of the images.
Due to the nature of MRI something called a Faraday cage is built into the room walls so as to prevent external radiofrequency waves (such as from the local radio station!) from distorting images.
Can I be scanned without any equipment placed over me?
The equipment that may be placed around the area being examined is what we term a coil, which is essentially the piece of equipment that receives the signal, like an aerial, which go on to make the images. The reason these are placed over the area in question is that the closer these are the better the quality of pictures made. In some circumstances it may be we can acquire some adequate images without using these but this may have an impact on the diagnostic quality and is something the scanning staff will be able to discuss if you have concerns.
Do you scan the whole body? Can you check out other body parts at the same time?
Whilst your whole body may be within the scanner, the scans performed are very focused and it is only the area in question that is being looked at. Therefore we are guided by your referrer as to what scans are required which is set out on a request form or referral letter. This is something like a Doctor’s prescription which means only what is signed for can be scanned. The request form also then provides an indication on how much time we set aside for your appointment and cannot be added to.. If there are other areas of concern then please discuss this with your referring clinician.
Do I have to put a gown on?
Whether or not you are asked to change depends both on what is being scanned and what exactly you are wearing.
We generally advise patients to try and attend with loose fitting clothes with minimal metal fastening, or to bring something along with them, such as pyjamas or jogging bottoms etc. Even then if there are multiple layers of clothing we would suggest taking off top layers or thick jumpers so that you don’t get too warm during the scan.
Any loose metal on clothing or items in pockets has the potential to be ferromagnetic and will therefore be pulled towards the scanner at high speed. Where metal fastening are over or close to the area being scanned these need to be removed in order to prevent the distortion it causes to the images. Even then, any metal or loops of metal within the magnet which are in contact with skin (such as necklaces or bracelets) have the potential to induce heat and therefore can warm adjacent skin leading to possible skin burns. Whilst this is rare, we do all we can to try and minimise this and so if it can be removed we recommend it is. Some tattoo dyes also contain fine metallic particles which can also heat so if any discomfort is felt please alert a member of staff immediately.
Why do I have to remove all my metal when it is only my head being scanned?
The magnetic field used for MRI extends to the edges of the scan room, and due to the strength of this magnetic field any ferromagnetic items taken into the scan room will be pulled towards the scanner at high speed, causing potential harm to anyone in its way and/or the scanner itself.
Even where metal is not ferromagnetic there is potential for metallic items to heat up during the scanning process. Therefore what can be removed should be so as to reduce the risks.
How much radiation do I receive?
There is no ionising radiation used in the acquiring of MR images. Once cleared to be safe to enter the magnetic field the imaging tool is a safe technique used to image the body with no adverse side effects.
I have had a MR scan recently, is it safe to have another one so soon?
There are no long term, cumulative effects of having multiple MRI scans.
Can I eat and drink as normal?
Unless advised otherwise you can eat and drink as normal prior to your MRI scan. For comfort we would recommend ensuring you don’t need the toilet before starting your scan as this will help keep you relaxed and still throughout.
The main examinations where eating or drinking may be a consideration are; MRCP studies looking at your gallbladder and biliary tree and Small Bowel studies – for which specific local guidance will be provided by the scanning department.
In such cases if you are diabetic please get in touch and be sure to bring some food with you for once the scan is complete.
What is the dye injected?
Gadolinium is a mineral based contrast media used to highlight certain structures or pathologies on the scans which help our Doctors with their diagnosis. It is a relatively safe drug although as with any medication there are always some people who may suffer some form of adverse reaction. This will all be explained in more detail by the members of staff performing your scan on the day. The main advice is to drink plenty following the injection but there is no reason you cannot continue as normal afterwards.
Do you see the pictures and can you tell me what is wrong on the day?
The person who operates the scanner is not the person who will write a report on what is shown. Therefore they cannot tell you anything immediately. Your GP or whoever referred you will get a written report plus copies of the images.
However, if anything which concerns us is seen, your GP/whoever referred you will be telephoned and action taken as appropriate as soon as practicable.
Exact timeframes vary between sites but should you need to chase results please contact your referring clinician not our scanning departments.
Do you offer any relaxants to help me manage my anxiety and claustrophobia?
We cannot prescribe any medications within our scanning departments, and should you feel you need some relaxants such as diazepam to help get through a scan then please get in touch and make an appointment with your GP.
Please make the imaging department aware you have or will be taking some medication on arrival.
For your safety please ensure someone accompanies you for your scan and is able to drive you home if necessary as many of these medications can make you feel drowsy.
As an alternative please see our signposting section for alternative help with preparing for and managing your MRI Scan. Due to improvements in scanner design and the support of our imaging professionals many people nowadays find coping with a scan much easier than first expected, and this is an area we continue to investigate and improve upon.
Will I fit into the scanner?
The bore used in our conventional scanners is 60cm or 70cm in diameter. While there are weight limits on the scan table, the main consideration is around patient overall build when laying down. Our Radiographers will assess this at the time of your scan and work with you to ensure your comfort. Where there may be limitations due to your size, this will be discussed with you at the time and alternatives suggested. Should you have any concerns around your size and whether you will be able to have a scan, please contact the site at which you are booked on the appointment letter received.