Magnetic Resonance Imaging

Magnetic Resonance Imaging (MRI) is primarily used in medical imaging to visualize the structure and function of the body. It provides detailed images of the body in any plane and can be reconstructed into a three dimensional image. MRI has much greater soft tissue contrast than Computed Tomography Scan (CT Scan or CAT Scan) making it especially useful in neurological, musculoskeletal, cardiovascular, and oncological imaging. Unlike the CT scan it uses no ionizing radiation, but uses a powerful magnetic field to align the magnetization of hydrogen atoms in the body. Radio waves are used to systematically alter the alignment of this magnetization, causing the hydrogen atoms to produce a rotating magnetic field detectable by the scanner. The collected signals are interpreted by a computer to create a composite, three-dimensional representation of your body. Any two-dimensional plane (slice) can be electronically created from this representation and displayed on a video monitor for examination. These images can be converted from the screen into photographic film for further viewing and analysis. There are no known harmful effects from exposure to the magnetic field or radio waves used in making MRI images. If your scan requires the injection of a contrast material, there is a very small risk of an allergic reaction. An MRI is a time consuming investigation compared to a CT Scan or and X-Ray. Some parts of the body, such as bone, are better investigated by simpler techniques. It is also not good for emergencies or accidents because of the long time it takes and the fact that all other medical equipment has to be removed from the room while the machine is running. Fast Facts:

1. Know harmful effects from exposure to the magnetic field or radio waves
2. May require a contrast material (which may cause allergic reaction)
3. Can identify brain tumors, stroke and damage from heart attack or heart disease and many other items that will not show up under X-Ray Imaging
4. It takes a long time compared to X-Rays or CT Scans
5. A version called and MRA can observe arteries

Disclaimer: The content in this page is not a substitute for professional medical advice. Please contact your doctor before beginning any Magnetic Resonance Imaging program.

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