MRI Essay Example | Topics and Well Written Essays - 2000 words

MRI - Essay Example Slice thickness, is one important parameter, which divides the body part being examined into sections of varying width or thickness. The result of examination depends on the slice thickness. If it happens to be a minute problem, then the slice thickness will be small, because a larger slice thickness might result in erasing small lesions or pathologies. MRI is mainly used to look into the brain and the nervous system of human body to figure out the inconsistencies using the functional magnetic resonance imaging, as these parts happen to be the most delicate parts of human body. Prasad (2005, 292) states that the 'MR images are in effect computer generated visual reconfigurations of physical data such as the relaxation times of hydrogen atoms that are found abundantly in the body.' More than two third of our body is made up of hydrogen atoms. Hydrogen exists in different forms in our body. For example water (H2O), consisting of two H atoms and one O, makes up about 70 percent of human body. In addition Hydrogen atoms are also present in the tissues and fat present in human body. When magnetic energy is sent into our body using radio frequencies, the hydrogen atoms absorb the magnetic rays and send out the same magnetic energy, depending upon the extent of magnetisation. As the nuclei of the hydrogen atoms happen to be in the form of small magnets, so when the magnetic fields change in their surroundings, they respond accordingly. This movement is recorded by the MRI equipment which in turn is analysed by the healthcare professionals to decipher the exact composition. As the experiments started off with an emphasis on nucleus, in early days MRI was known as Nuclear Magnetic Resonance (NMR). Since the process itself is stated to involve very small amount of energy, the normal biochemistry of human body is not affected. The key requirements for performing an MRI include; A strong magnetic field through the primary magnet, emanating out of the a magnetic which could be a permanent, resistive or a superconductive Gradient magnets for fine tuning the magnetic fields The scanning table on which the patient is allowed to lie Attached computers and film for taking the printout of the scan The individual who is to undergo MR imaging is allowed to comfortably lie on a sliding table. The table is then slid into a cylindrical structure which is surrounded by the magnets. Once everything is in position, the magnetic field is turned on; this creates a 2-dimensional image of the particular body part of the person on the computer screens. A coil is placed around the body part/ object which is under observation for MRI, exclusively to pick up the signals for the image. Well, just to make things easier a talk-back system is also in put in place so that after the start of clinging sound the patient doesn't feel uncomfortable, and if required he can communicate with the radiologist. The procedure may last for about 25-50 minutes depending upon the requirements and the complexity of the patient condition. There are in general two to six imaging sequences, each lasting for about 10-15 minutes. Since the process involves magnetic fields, it is therefore advised that anybody having m etallic implants in their bodies must inform the radiologist beforehand, so that adequate