MRI's
Magnetic resonance imaging, or MRI, is based on the fact that atoms contain both positive and negative charges. MRI's use magnetism to use the electrical charges of atoms to create images of materials. The most common use for MRI's is in medical diagnosis. MRI's were available for patients starting in 1984 (Nordenberg, 1999).
One of the MRI's greatest advantages is its relative safety compared to some other imaging techniques. The first method for imaging the body, x-rays, which use radiation to create its images. Another advantage is that MRI's can image less dense tissues than x-rays can (Nordenberg, 1999). But where the MRI has a tremendous advantage over x-rays is in its ability to create 3-dimensional images. It also does a better job of showing contrast between dense parts of the body, such as bones, and softer tissue, than other imaging techniques (Nordenberg, 1999).
How They Work
In medical use, MRI's focus on hydrogen atoms. The magnetic atmosphere the patient enters is a lop-sided one: the magnetic field generated will be stronger one side than the other, resulting in variances in resonance frequency, or how rapidly the hydrogen molecules vibrate in response to the magnetic field (Tro, 2006). That vibration, or resonance, is artificially created and controlled by the very powerful magnets pulling on hydrogen molecules in the body. These patterns are translated by a computer into a detailed image of the body part being imaged. An MRI creates such clear images between dense tissue and softer tissue because softer tissue contains more water, and hence, more hydrogen (Gould, DATE).
MRI's actually use four different types of magnets. The first is a resistive magnet. Resistive magnets are made by wrapping coils of wires around a center. An electric current then runs through the center, creating a magnetic field (Gould, DATE). These magnets draw a lot of electricity and are impractical for creating extremely powerful magnets....
Magnetic Resonance Imaging History of MRI The Magnetic Resonance Imaging (MRI) was first tested in Budapest Hungry in 1882. Later in 1937, Professor Isidor Rabi of Columbia University assembled a Nuclear Magnetic Resonance. This tool was effective because it could absorb and emit radio waves after exposure to a strong magnetic field. Professor Carr Herman produced one-dimensional MRI imaging processor in 1952. The nuclear powered NMR was instrumental in experiments developed to
MRI Magnetic resonance imaging uses magnetic field and radio wave energy to diagnose and capture images of the organs and the structures inside the body. It is a test which uses nuclear magnetic resonance in order to take pictures which can then be used to diagnose problems for instance injury, blood vessel disease, tumors and the like. A highly unique method, it's known for diagnosing problems which cannot be found with
Magnetic Resonance System on patients Magnetic resonance System (Imaging), here after referred to as (MRS), or nuclear magnetic resonance imaging (NMRI), is a medical imaging technique widely used in radiology to visualize detailed internal structure and limited function of the body. It provides great contrast between the different soft tissues of the body, making it particularly useful in neurological (brain), musculoskeletal, cardiovascular and ontological (cancer) imaging. MRS uses a powerful
Magnetic Levitation Propulsion Systems in North America and Around the World How Magnetic Levitation Propulsion System Works? Development of the Maglev Technology Design Differences in the German and Japanese Maglev Technology Advantages of Maglev Disadvantages Cost Factor Other Applications and spin-offs Potential Projects in the U.S.A. Magnetic Levitation Propulsion Systems With air travel and the highways becoming increasingly congested, the need for an efficient, fast and comfortable mode of alternative travel has been felt in many countries of the
Certainly, it must be stated that more study is needed and worth pursuing in this diagnostic method in forensics. References Bisset, R. et al. (2002) Postmortem examinations using magnetic resonance imaging: four-year review of a working service BMJ 2002;324:1423-1424 (15 June) Online available: http://bmj.bmjjournals.com/cgi/content/full/324/7351/1423 Post Mortem Magnetic Resonance Imaging (MRI) (2005) http://www.forensicmed.co.uk/developments.htm Alderstein M.E., Peringa J., van der Hulst V.P.M, Blaauwgeers H.L.G., van Lith J.M.M. (2003), 'Perinatal mortality: clinical value of post-mortem magnetic
New Tech Structural brain imaging has revolutionized the fields of neuroscience and medicine. The American neurosurgeon Walter Dandy first introduced ventriculography and later developed pneumoencephalography, early imaging methods in the early 1900s; however, both procedures carried significant risks and could be quite painful. The technique of cerebral angiography was introduced in the late 1920's by neurologist Egas Moniz and this technique became refined and is still an important tool that is
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