Magnetic Resonance Imaging
Magnetic Resonance Imaging (MRI) uses pulsed radio frequency and magnets to create images used for screening and diagnosis. MRI creates a three-dimensional representation of the body which can be studied from many different angles on a computer monitor. Magnetic resonance images show differences in water content between various body tissues, as a result, MRI is especially suited to detecting disorders that increase fluid in various body tissues such as tumors, infection and inflammation.
How is an MRI performed?
The MRI unit is a large cylinder-shaped tube surrounded by a circular magnet. You will lie on a moveable examination table that slides into the center of the magnet. Straps and bolsters may be used to help you stay still and maintain the correct position during imaging. If a contrast material will be used, an IV will be inserted into a vein in your arm or hand. MRI exams generally include multiple runs (sequences), some of which may last several minutes.
The MRI scanner will produce loud thumping and humming noises during imaging. It is normal for the area of your body being imaged to feel slightly warm, but if it bothers you, notify the radiologist or technologist. It is important that you remain perfectly still while the images are being recorded.
The computer workstation that processes the imaging information is located in a separate room; however, the technologist will be able to see, hear and speak with you at all times using a two-way intercom. The entire examination is usually completed within one hour.
How do I prepare for the test?
High quality images are assured only if you are able to remain perfectly still while the images are being recorded. Some patients find it uncomfortable to remain still during MR imaging while others experience a sense of being closed-in (claustrophobia).
Jewelry and other accessories should be left at home if possible, or removed prior to the MRI scan. Metal and electronic objects are not allowed in the exam room because they can interfere with the magnetic field of the MRI.
In most cases, an MRI exam is safe for patients with metal implants, except for people with implanted defibrillators, cochlear ear implants or clips used on brain aneurysms. You should tell the technologist if you have medical or electronic devices in your body because they may interfere with the exam or potentially pose a risk.
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