Magnetic resonance imaging (MRI) is a computerized method of viewing the body in a three-dimensional image to detect a wide variety of abnormalities. A strong magnetic field is used to obtain images of soft tissues and bones. Magnetic resonance imaging provides more details than computed tomography or regular radiography.
Magnetic resonance imaging is painless and does not use radiation. In some cases a contrast agent (dye) is injected into the patient's bloodstream to improve the visibility of certain structures. Specialized magnetic resonance techniques used at Barrow include cardiovascular magnetic resonance imaging, diffusion imaging, functional magnetic resonance imaging, magnetic resonance image guidance, peripheral vascular magnetic resonance imaging, magnetic resonance spectroscopy, and magnetic resonance angiography.
Magnetic resonance image of a normal brain.
Most patients tolerate magnetic resonance imaging very well, but there are a few limitations. For instance, some individuals with implanted devices (pacemaker or artificial joints) or metal in their body may be unable to undergo magnetic resonance imaging because of the strong magnetic field.
The physician ordering the magnetic resonance imaging and the magnetic resonance imaging staff determine if it is safe for the patient undergo the procedure. During the test, patients must lie on a bed that slides into the scanner. A magnetic resonance image of the head or neck area requires the patient's head and upper body to enter a relatively narrow canal.
Individuals with claustrophobia may require light sedation to improve their ability to tolerate the closeness of the machine. To obtain the best images, patients must not move during the examination. Small children undergoing magnetic resonance imaging may require sedation to ensure the best results.
Cardiovascular Magnetic Resonance Imaging
A cardiovascular magnetic resonance imaging study evaluates the heart, heart valves, and blood flow. The procedure is painless and noninvasive, which means sedation is not required and there is no incision or insertion of a catheter into the body.
Diffusion imaging uses magnetic resonance imaging methods to evaluate areas of ischemia in the brain (brain cells destroyed by lack of blood flow and oxygen) to determine the location and severity of a stroke. The procedure is painless and noninvasive, which means sedation is not required and there is no incision or insertion of a catheter into the body.
Functional Magnetic Resonance Imaging
||Functional magnetic resonance imaging study of a normal brain, with activation of mesial temporal structures with memory task.
Functional magnetic resonance imaging can be used to evaluate which areas of the brain are responsible for different functions, such as speech, comprehension, movement, and vision. Functional magnetic resonance imaging studies are primarily used in research.
Magnetic Resonance Imaging Guidance
Magnetic resonance imaging guidance can be used during surgery to help surgeons to plan the surgical approach and to locate tumors precisely. Before surgery, patients undergo magnetic resonance imaging guidance with special markers placed on their head. The markers are used to register landmarks so that the magnetic resonance images can be entered into a computer in the operating room. The surgeon uses an instrument called a "wand" to touch the surgical area. The wand sends information to the computer to identify the tumor location and size. Magnetic resonance imaging guidance is used primarily for tumors involving soft tissues of the brain, spine, blood vessels, and nerves.
Peripheral Vascular Magnetic Resonance Imaging
Peripheral vascular magnetic resonance imaging can be used to detect blood clots, blood flow patterns, and blood vessel abnormalities in the arms and legs.
Magnetic Resonance Spectroscopy
Magnetic resonance spectroscopy can be used to evaluate brain tumors, neurological diseases, and epilepsy. The study evaluates the chemical composition and metabolic activity of brain tissue. This information is used to diagnose, monitor changes, and evaluate seizure activity.
Magnetic Resonance Angiography
Magnetic resonance angiogram on a patient with a complete ICA occlusion.
Magnetic resonance angiography is used to evaluate blood vessels in the head and neck. The study shows blood flow patterns and blood vessel abnormalities. Sedation is not required, and there is no incision or insertion of a catheter into the body. In some cases, a contrast agent (dye) is used to improve the visibility of certain structures.
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