Magnetic Resonance Imaging Essay

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Magnetic Resonance Imaging

MRI is a procedure, in wide use since the 80s, to see the anatomy of the internal organs of the body. It is based on the phenomenon of nuclear magnetic resonance (NMR), first described in landmark papers over fifty years ago (Rabi et al. 1938; Rabi, Millman, and Kusch 1939; Purcell et al. 1945; Bloch, Hansen, and Packard 1946) (4 ). . The MRI is a valuable diagnostic and research tool with also practical applications for surgical planning and conquering diseases. This imaging procedure is painless and non-invasive although sometimes discomforting as the patient lies down in a body tube that surrounds them. For many years, closed MRI units have been the standard in helping physicians make a diagnosis. These
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So, the human body can be pictured as a 3D-map of changes of magnetic field with a human body form (1). . Radiofrequency gives us the density of those changes and we then obtain the images of the internal anatomy.

Radiofrequency gives energy to the spin of the protons, increasing the amplitude of their turns without changing the frequency. Now the 3D-magnetic map becomes a 3D-map of energy. Each particular point in the body has a particular energy (or intensity, in terms of radiofrequency). If radiofrequency is no longer applied to the body, the proton-spins recover the original state and in that moment release radiofrequency waves. Now we have a 3D-map of radiofrequency and this radiofrequency can be registered with coils.

The rest of the procedure is done by the computers that convert the signal intensity, the signal phase, and the signal location into a matrix of dots with different values. Each value is represented with a tone of gray. The minimum value is black, and the maximum value is white, and in between is a scale of gray. At this point We have a MRI image. The MRI provides both structural and chemical information and distinguishes moving blood from static brain tissue (2 ). . In functional magnetic resonance imaging we employ two components: a task and a result. The task is an

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