HEALTH ZONE – MORE ABOUT MRI SCANS
MRI Scans are a Safe Way to Take Pictures of Inside the Body
What are MRI and FMRI Scans?
MRI stands for ‘Magnetic Resonance Imaging’. MRI is a fairly new concept that has been used from the 1980s.
MRI is an extremely effective method in creating pictures of every internal part of the body – blood vessels, nerves, muscles, organs, joints, bones – which can help in discovering any abnormalities which should be treated.
One of the main benefits of MRI is that the scan uses no X-rays or radiation. This means that MRI is harmless to the person having the scan and does not hurt. Radio waves create a magnetic field which is sent through the body, which in turn, causes the body’s cells to vibrate. The nuclei of the atoms are forced into different positions by these vibrations. As the nuclei move back to their original positions, they send out electronic signals which can then be interpreted by a computer. The computer can turn these interpretations into detailed pictures of the area being scanned.
An MRI scan is also useful as it is able to record clear images of parts of the body which are surrounded by bone tissue such as the brain or the spinal cord. Before having an MRI scan, you may have a special type of dye injected into you called contrast medium, which will help the images produced by the scan to be clearer.
FMRI stands for ‘Functional Magnetic Resonance Imaging’ and is used to ‘map’ the brain and to record its activity while the subject looks at something, touches something or listens to something. FMRI scans are useful for determining which parts of the brain are activated when certain tasks are performed.
FMRI works by recording images of the brain where there is an increased oxygen supply, which means that there is an increase of activity in that particular area. FMRI has proved to be useful in psychology research as the researchers can discover which parts of the brain are activated when certain cognitive tasks are performed. These tasks could include looking at pictures, touching something or listening to something.
What are MRI Scans Used for and what Problems can they Detect?
MRI scans can provide detailed pictures of parts of the body which other methods may not be able to do. For this reason, MRI can be useful in detecting abnormalities in organs, blood flow, bones and joints etc. MRI has proven to be effective in detecting health problems ranging from tumours to torn ligaments.
You Should Talk with Your Doctor if You Think You May Have Metal in Your Body.
Who can and who can’t have an MRI/fMRI Scan?
MRI scans are a safe way to record images of the body and because of its safety, there is usually no restriction on how many MRI scans you can have. However, not everyone can have an MRI scan. Due to the extremely strong magnetic field created by the MRI, anyone with metal in their body will more than likely not be able to have the scan. Below are a few examples of metallic objects that may be found in the body which can cause problems for the MRI scan:
Pacemakers (used to correct any abnormalities in the heart’s electrical system)
Heart Valves (used to replace dysfunctional valves of the heart)
Metal Brain Implants (commonly used in sufferers of stroke)
Metal Eye or Ear Implants (used as an aide to people with a loss of hearing or sight)
Metal Pins in Bones (used to realign broken or fractured bones)
Patients who have had injuries caused by bullets or shrapnel, or who work with metals will need to be analysed to determine if they are compatible with an MRI scan.
If you have had a hip replacement or a dental implant, then the chances are that you will still be able to have an MRI scan. Most orthopaedic and dental implants are not magnetic and therefore will not cause a problem in the MRI scan. However, if you have any kind of metal in your body, or if you are unsure about your compatibility with an MRI scan, you should always seek the advice of your doctor before having the scan.
MRI scans are usually not performed on women who are twelve weeks pregnant or less. The long-term effects of the strong magnetic fields used in MRI on developing foetuses are not yet known.
The MRI machine that you will be required to lie down in can, to some people, feel quite claustrophobic. If you have any concerns about any claustrophobia you may experience, you should talk to your doctor before having the MRI scan.
MRI is Completely Safe.
Why would I have an MRI /fMRI Scan?
If you see a study in our Studies section of our website that requires people to have an MRI scan, then this could be a good opportunity for you to make some extra money while helping research. MRI or fMRI scans are usually completely non-invasive – no drug or substance will enter your body. Although sometimes, a special dye will be injected to increase the clarity of the images that are produced by the MRI.
MRI is completely safe, providing you do not have any of the metal implants that were discussed above and you are not a woman who is less than 12 weeks pregnant. For this reason, any MRI scans performed are usually done so on an out-patient basis. This means that you can go to the clinic, have the scan and leave soon after. When having an MRI for research purposes, you can receive monetary compensation for your time and inconvenience and will usually be given a picture of your brain, which not everyone can say they have!
What can I expect when I have an MRI or fMRI Scan?
Having an MRI scan is a relatively quick and simple procedure. You will not have to stay overnight at the hospital and you should be able to go home almost straight away after the scan. The actual scan will probably take up to an hour, but you should allow more time for the whole process to be complete.
When having the scan, it is very important that the subject stays as still as possible as any movement can blur the MRI image. For this reason, children are sometimes sedated to keep them from moving around. If you have expressed feelings of claustrophobia to your radiographer prior to the scan, they may give you some medication to make you feel calm throughout the duration of the scan.
Before the scan takes place, it will be necessary for you to remove any metal jewellery, hair clips, hearing aides etc that you may have on. Anyone staying with you in the scanning room will also have to remove any of these items. In some cases, a dye will be injected into your veins (usually the back of the hand) to create a clearer MRI image. This will be done prior to the scan taking place.
The actual scan will involve lying on a cushioned table which will slide into a big, tube like machine (the MRI scanner). The MRI scan will not hurt and it is completely safe. However, some people may find it uncomfortable as it is required that you keep still throughout the scan. There will be periods of time in between each scan where you will be able to move. Depending on the detail of the scan and the amount of pictures being taken, the MRI scan should take between 15 and 45 minutes to complete but could take longer.
An MRI scan is completely safe and is a relatively quick procedure. If you find a study which requires people to have a scan performed, then this may be a great way for you to earn some extra money while helping the advancement of research. You will probably get a picture of your brain too!