The physics of MRI
According to the electromagnetism, any material that transmits current generates a magnetic field which surrounds it. When the conducting material is made into a sphere, the magnetic field aligns itself uprightly to the area of the sphere. Comparable to this idea of the magnetic field is the area which is generated by ‘negatively charged electrons’ that goes round the nucleus within a substance. The spinning speed of the material generates a minute magnetic field called magnetic moment. In addition, under general situation, these instants do not have stable direction, thus, there is no common magnetic field. Nevertheless, when nuclei are laid within an exterior magnetic field, for instance, when a sick person is put on the MRI scanner, the nuclei start to align themselves in a specific manner which is based on the quantum physic’s law. As a result, if there were hydrogen nucleus, two distinct levels of energy will be formed. This is a greater energy level in which the magnetic instants are contrasting the peripheral magnetic field and the lesser energy level where the nuclei are lined up with the field (Counter, Olofsson, Borg, Bjelke & Grahn 2000, p 14).
Similarly, when the nuclear charge is put on the field, it precesses within the magnetic field in a movement hat is equivalent to the revolving top. The rate of recurrence of precession is based on the Larmor equation. Additionally, the invariable of proportionality in the Larmor equation results into magnetogyric ratio which produces the MR images with the nucleus having particular value. For the positive charge, in a magnetic field having the power of 1.5 T, this rate of recurrence is approximately 63.8 MHz; this refers to the RF (radio-frequency) range. Therefore, the powerful magnetic field of the MRI is formed by moving an electric current via the loops of the wire. As this process continues, some coils within the magnet transmit and obtain radio waves. As a result, this provokes protons (positive charges) within the body to arrange themselves. Immediately they are arranged, radio waves are received by positive charges that encourage spinning. Thus, energy is emitted after the elements are excited and as a result, they release energy signals which are absorbed by the coil. The data that has been gathered is later transferred to an electronic machine which processes the entire signals and produces it into body images (Le Bihan, Breton, Grenier & Cabanis 1986, pp. 404-406).
MRI technique and advantages over CT
MRI is utilized to effectively recognize and identify tumors, and to examine if the cancer has extended. For instance, MRI scanning can be utilized in examining joints, abdomen, chest, nervous system, spinal column and pelvis. The picture and resolution provided by magnetic resonance imaging is very comprehensive and the examination could be utilized to identify minute structural alterations within the body. In addition, MRI is used in biochemical research like measuring the content of the calcium and magnesium in the body. MRI is also utilized in producing brain images and retrieving data regarding the brain chemicals. In addition, cancerous transformation involves great biochemical alteration such as changes of the cell metabolism energy. Tumor development results into heterogeneity within the blood circulation; thus, leading into metabolic demands and focal necrosis. Hence, it interferes with the substance mechanism transportation along the cell membranes including BBB (blood brain barrier). Therefore, these biochemical alterations can be researched or investigated through the MRI. MRI is also used to effectively recognize the size of the tumor and biochemical investigation offers extra information which is significant for tumor classification, hence appropriate diagnosis and treatment Luechinger, Duru, Candinas, & Boesiger 2004, 73).
The great advantage of MRI over CT scanning is its quality or exceptional soft-tissue contrast that could be greatly modified without moving the sick person. MRI gives powerful and greater contrast between various body tissues when compared to computed tomography (CT). This makes MRI more applicable particularly in imaging such as oncology, musculoskeletal, brain imaging and cardiovascular imaging. Additionally, MRI can be carried out in any section of the human body unlike CT scanning, since it does not incorporate ionizing radiation in its process. MRI generates more comprehensive pictures or images of the body organs and tissues than CT imaging. Moreover, it distinguishes between common tissues more efficiently, and generates less comprehensive images of bone than CT scanning (Moseley, Cohen, Mintorovitch, Chileuitt & Shimizu 1990, pp. 332-335).
In addition, MRI gives comparable resolution which has better contrast resolution while CT offers fine spatial resolution. Thus, MRI scanning has the capacity to bring in the distinction between two subjective common though not indistinguishable soft tissues while CT scanning has the capacity to only differentiate two formations, at a subjective small length from one another as separate (Haacke, Brown, Thompson & Venkatesan 1999, p. 34).
Therefore, since MRI scanning is more superior and safer than CT scanning, and can be used effectively in diagnostic measures and biochemical research, most of the health care facilities should implement it in order to improve the quality of life of the patients. Hence, AHA should look into the concept of making its major capital equipment funds available to St. Katherine’s hospital. This will enable the hospital to adopt the concept of constructing a new MRI facility in order to enhance the reputation of the health institution as a center of medical research.
Reference List
Counter A., Olofsson, A., Borg, E., Bjelke, B., & Grahn, H. 2000. Analysis of Magnetic Resonance Imaging Acoustic Noise Generated by a 4.7 T Experimental System. Acta Oto-Laryngologica, 120 (6): 739–743.
Haacke, E., Brown, F., Thompson M., & Venkatesan, R. 1999. Magnetic resonance imaging: Physical principles and sequence design. New York: J. Wiley & Sons.
Le Bihan, D., Breton, E., Grenier, P., & Cabanis, E. 1986. MR imaging of intravoxel incoherent motions: Application to diffusion and perfusion in neurologic disorders.. Radiology, 161 (2): 401–7.
Luechinger, R., Duru, F., Candinas, R., & Boesiger, P. 2004. Safety considerations for magnetic resonance imaging of pacemaker and ICD patients. Herzschrittmachertherapie und Elektrophysiologie, 15: 73.
Moseley, E., Cohen, Y., Mintorovitch, J., Chileuitt, L.&, Shimizu, H. 1990. Early detection of regional cerebral ischemia in cats: Comparison of diffusion- and T2-weighted MRI and spectroscopy. Magn Reson Med, 14 (2): 330–46.