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Magnetic Resonance Imaging (MRI)

Magnetic Resonance Imaging
MRI scanning is a powerful medical diagnostic tool that uses a strong magnetic field to produce high-quality, images in multiple planes or directions. The images are generated using superconducting magnets and pulsed radio waves. Magnetic resonance imaging uses non ionising radiation, unlike x-rays which uses radiation.

When are MRI scans used?
An MRI scan can be used as an extremely accurate method of disease detection throughout the body and is most often used after the other testing fails to provide sufficient information to confirm a patient's diagnosis. In the head, trauma to the brain can be seen as bleeding or swelling. Other abnormalities often found include brain aneurysms, stroke, tumors of the brain, as well as tumors or inflammation of the spine. An MRI scan can evaluate the structure of the heart and aorta, where it can detect aneurysms or tears. MRI scans are not the first line of imaging test for these issues or in cases of trauma.It provides valuable information on glands and organs within the abdomen, and accurate information about the structure of the joints, soft tissues, and bones of the body. Often, surgery can be deferred or more accurately directed after knowing the results of an MRI scan.

Benefits of MRI:

• MRI is non-invasive and does not use radiation MRI does not involve radiation 
• MRI contrasting agent is less likely to produce an allergic reaction that may occur when iodine-based substances are used for x-rays and CT scans 
• MRI gives extremely clear, detailed images of soft-tissue structures that other imaging techniques cannot achieve 
• MRI can easily create hundreds of images from almost any direction and in any orientation. Unlike techniques that examine small parts of the body (i.e. ultrasound or mammography)
• MRI exams can cover large portions of the body 
• MRI can determine if a cancer has spread, and help determine the best treatment 

Do not go for a MRI scan if you:·        

• are (or might be) pregnant.
• have a heart pacemaker or an artificial heart valve
• have any electro-mechanical devices used for drug delivery
• have any surgical clips
• have a cochlear implant, a neurostimulator or a programmable hydrocephalus shunt
• have had any operations on your head
• have any metal implant in your body
• have had an injury to your eyes involving metal or metal fragments

Disadvantages of MRI:

• MRI is comparatively expensive
• MRI will not be able to find all cancers (i.e. breast cancers indicated by microcalcifications)
• MRI cannot always distinguish between malignant tumors or benign disease 
• MRI is not painful, but the patient must remain still in an enclosed machine, which may be a problem for claustrophobic patients
• An undetected metal implant in a patient’s body may be affected by the strong magnet of the MRI unit
• There is a small chance that a patient could develop an allergic reaction to the contrasting agent, or that a skin infection could develop at the site of injection
• If a patient chooses to be sedated for the scanning, there is a slight risk associated with using the sedation medication

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