What Is MRI

This is one unique technology employed in the field of radiology to study the details of the internal structures of the human body. This technique makes use of the ability of the NMR (Nuclear Magnetic Resonance) to capture images of the large nuclei or atoms in the human body.

MRI machines generally employ the usage of heavy magnetic fields to determine the magnetization power of the atomic nuclei in the human body. This also uses radio frequency waves at the same time to alter the alignment of this magnetization. This in turn causes the nuclei to deliver a rotating magnetic field, which in turn is detectable by the scanner. The information obtained can be used to construct the details of the scanned area. The entire system is dependent on the magnetic field gradients that cause nuclei at different locations to rotate with alternating speeds. The difference in the gradients at various directions is what that delivers the two dimensional and the three dimensional images in various orientations.

The applicability of the MRI was detected and thus, Paul Lauterbur and Sir Peter Mansfield were given the Nobel Prize in Physiology or Medicine during the year 2003. This prize attributed specifically to the concept of Magnetic Resonance Imaging and thus acknowledged the ability of Lauterbur’s capacity to determine the spatial location, which helped the generation of a wide range of 2D images in an instant. With Sir Mansfield, the credit was attributed to the development of mathematical formalism and techniques for the fast grading process.

In the field of medicine, MRI is used to differentiate the various pathologic tissues in the human body. Say for instance, the normal brain can be distinguished from a brain tumor. The advantages of this method are that it is completely harmless to the human body and uses the non-ionizing radiation in the radio frequency range. This is unlike the CT scans and the conventiaonal X-rays where ionizing radiation is used. Although CT delivers superior quality resolution, the MRI provides radiation with far better quality and thus helps to distinguish between two roughly similar tissues, although not identical ones. This ability is delivered by means of the pulse sequences that are used by the modern MRI medical scanner, each of which is optimized to deliver a contrast based on the sensitivity of the technique.

There are many types of MRI that can be differentiated based on the type of complexity and gradient that can be scanned using them. T1 weighted scans help to differentiate fat from water, T2 enables the easy identification of the cerebrospinal fluid and thus, both these scans in conjunction help to identify edema in the human body. The T2 star is another deviation from the T2 method where the contrast for a few types of tissues such as the venous blood is more differentiated from the rest. Spin density weighted MRI do not possess a contrast when it comes to the point of T2 or T1 decay.

Despite the various other techniques of identification that are prevalent today, it is apparent that MRI stands ahead the rest and delivers quality and optimal imaging as required. 

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