MRI
Magnetic Resonance Imaging (MRI)
Magnetic Resonance Imaging (MRI) is a powerful diagnostic imaging technique, which uses a strong magnetic field to diagnose various illnesses. MRI is used in medical diagnosis, as well as in research to acquires images of internal structures of the body, providing incredibly detailed information which may otherwise be difficult or impossible to obtain.
Preparation for an MRI Scan
Before an MRI scan, it is important that the patient is properly prepared. Depending on the type of procedure and the intended area of the body being scanned, different preparation processes will be necessary.
- Patients should wear clothing that is free of metal, such as buttons or zippers, and can often be asked to wear a hospital gown during the procedure.
- Any jewelry or other metal objects should be removed before entering the MRI room.
- Patients may be asked to stop taking certain medications and supplements before MRI scans.
- Women who are pregnant should obtain medical clearance before having an MRI.
The Procedure of the MRI Scan
The MRI machine is a large cylinder-shaped tube that contains a powerful magnet. It can produce high-resolution images. During the procedure, the patient will lie on a movable table which will slide into the cylinder. The MRI technician will control the scanning and positioning from a separate control room, and can communicate with the patient via a two-way intercom.
Once the table is in position, the patient will be asked to remain still and may be asked to hold their breath for brief periods of time, in order to obtain the best possible images. It is important to remain still and to not move during the scan, as this may affect the quality of the images. The scan itself is painless and does not involve any radiation.
Types of MRI
There are different types of MRI scans, which can be used for different purposes. Examples of these include:
- MRI Angiography (MRA): This type of MRI scan uses a dye and magnetic resonance imaging to create a detailed map of the arteries and veins.
- Dynamic Contrast-enhanced MRI (DCMRI): This type of scan is used to examine areas affected by cancer or vascular disease, as it can detect changes in the area where the contrast is injected.
- Proton Density Imaging (PD MRI): This type of MRI scan is used to detect abnormalities in the spinal cord or skull.
- Cardiac MRI: This type of MRI scan is used to diagnose heart problems and assess the severity of damage to the heart muscle.
Risks of MRI Scans
MRI scans are generally considered safe and pose very few risks. Some patients may experience feeling claustrophobic inside the MRI scanner. Some patients may also experience allergic reactions to the contrast dye, if it is injected for certain types of scans.
Why an MRI Scan is Performed
MRI scans are used to assess various medical conditions, and can be used to diagnose and monitor the progress of these conditions. MRI scans can be used to detect abnormalities in the brain, heart and other organs, in addition to detecting tumours, identifying areas of bleeding or damage and assess joint damage. MRI scans can also help determine the severity of various medical conditions.
When an MRI Scan Should be Performed
When to request an MRI scan will depend on a patient's individual situation and the advice of their doctor. In general, MRI scans are used in patients who have had a stroke, a head injury or other trauma, as well as those who have a history of cancer or other medical conditions, or those who appear to have an abnormality following an X-ray or CT scan. It may also be used to diagnose issues with the heart or spine or to detect a herniated disc.