Magnetic resonance imaging (MRI) Essay Example

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4Magnetic Resonance Imaging (MRI)

MAGNETIC RESONANCE IMAGING (MRI)

Problem Defination

Since MRI was introduced as a diagnostic tool, the number of persons being exposed to electromagnetic fields is on the rise. Health professionals use MRI scans as a tool to investigate what may be causing the symptoms observed in a patient. However, these risks have been found to have some side effects. This research paper looks into some of the benefits of using MRI scan as well as the risks associated with the technology and finding whether these risks have long-term health effects. Finally, a conclusion is made based on the findings.

Research hypothesis

The risks associated with MRI scan have no long-term negative biological effects in the body.

Introduction

MRI scanning

Magnetic resonance imaging (MRI) is one of the medical imaging techniques used in the medical sector to obtain images of the human anatomy and its physiological processes. The technology employs the use of strong radio waves, magnetic fields and field gradients generated from a large tube with very powerful magnets. About 70% of the human body mass consist of water molecules, which are made of hydrogen and oxygen atoms (Mudry, et al., 2003). Atomic nuclei have smaller particles known as protons, characterized by a magnetic dipole moment and are detectable by magnetic forces. MRI scans measure how water is spatially distributed in the body being imaged. The powerful magnets produce a very strong magnetic field down the tube that aligns the protons. Radio waves are then emitted into the body, interfering with the aligned protons and creating energy differences between the protons aligned against or with the field. When the radio waves are switched off, realignment of the protons occurs and signals are send to receivers. The re-alignment of protons produce distinct signals that that are used to form images of the scanned body part (Brown & Semelka, 2011).

MRI scans are used in the examination of almost all body parts, including the brain, spinal cord, bones, joints, the heart, breasts, blood vessels, lymph nodes and other important internal organs, such as prostate gland, kidneys, the liver, biliary tract, the womb, spleen, pancreas and other organs. The MRI scan images provide detailed information about these body parts and vital organs that may not be observed with computed tomography scan, ultrasound or X-ray. MRI is also done to detect problems such as internal bleeding, blood vessel diseases, infection, or tumors (Semelka & Elias, 2013).

Benefits and Risks of MRI Scan

Benefits

MRI stands to be the most prefered procedure that can be used to diagnose a number of abnormal conditions or potential problems in several parts of the human body. Generally MRI creates images that can clearly show the differences between healthy tissues or organs and unhealthy ones (Brown & Semelka, 2011). Physicians employ the MRI procedure in the examination of the brain, joints, skeleton, spine, abdomen, the heart, lungs, blood vessels, pelvic region, breast and many other body parts. MRI scans provide clear and more detailed diagnostic pictures of tissues and organs that are of most importance in the human body. Sometimes, the pictures can show unique details that other tests may not be able to reveal. This helps in discovering some abnormalities that other imaging techniques cannot reveal. In some instances, MR images of body parts, such as the liver, heart and other important organs, can accurately identify and characterize the specific disease. Several images can also be created from almost all directions and orientation (Mudry, et al., 2003). The MRI scanning can examine and cover a large part of the body and can diagnise a wide range of conditions. The procedure is painless, and given that the machine is non-invasive and does not use ionizing radiation, this makes the test safe for both children and expectant women. MRI contrasting dye agent is not likely to produce an allergic reaction that is likely for CT scans and X-rays when substances containing iodine substances are used (Semelka & Elias, 2013). Non-invasive observation of the biliary system can be carried out without the need of contrast injection. Using an MRI scan can easily determine if there is spread of cancer, as well as determine the best way of treatment.

Risks of MRI Scan

In general, MRI is a safe scanning technique if the necessary precautionary measures are considered. However, some incidences of causing harm to patients have been encountered during the MRI procedure.

Risks from metal implants

MRI employs the use of high magnetic fields which extend far beyond the machine exerting powerful magnetic forces on ferromagnetic metals nearby. MRI scans with heart pacemakers, cochlear and defibrillation device implants can cause malfunctioning of these implants. Interaction of the MRI magnetic field and radio frequency with ferromagnetic objects can produce a torque of the object or heating during the MRI scan procedure (Syed & Mohiaddin, 2012). MRI facilities are well equipped with a comprehensive screening process for reviewing contradictions before scanning to ensure that the scan is done only to patients it is safe for. Provided a patient does not have any metallic implants in their bodies or notify their physicians of such medical implants, the MRI scan is considered to be safe. Nowadays, newer medical implants that are MRI-compatible are being manufactured to prevent this risk.

Pregnancy risks

MRI scans produce noises while processing and causes slight heating of the body as it absorbs the energy generated. The test should be avoided during organogenesis in the first trimester of pregnancy since the fetus is sensitive to these effects. However, beyond this period, MRI scans are considered safe and can occasionally be used to monitor the growth of an embryo only if essential (Webb, 1988). Gadolinium-based contrast agents are usually avoided during pregnancy or administered in very low doses if needed to provide essential diagnostic information.

Risks due to the contrast media

The contrast dye, gadolinium chelate, used in MRI is not iodine-based unlike other agents used in X-rays, and therefore, rarely leads to allergic reactions. Severe allergy reactions may occur in 1 out of 10,000 people administered with the dye. The physician should be well informed about any previous allergic reactions to contrast media or undergoing medications before performing the MRI test. In some rare cases, people with kidney problems may suffer from a serious condition known as systematic nephrogenic fibrosis after being administered with gadolinium chelate (Weishaupt, et al., 2008).This condition causes building up of fibrous tissue in joints, muscles, the skin and other internal organs. A doctor needs to assess a patient’s blood to be sure that it will be safe to use the gadolinium contrast dye.

Risks associated with sedation or general anaesthesia

Young children and babies below six years of age, and also occasionally adults, for example, those who experience a lot of pain or agitated, will need a light an aesthetic administration before they can be exposed to the MRI machine. This is they cannot stay in a still position for the required time to obtain quality pictures. The radiographer will need to discuss with the adult accompanying a young child on the risks and benefits of using anesthesia before the scan. A sedative may be requested, especially if one is very anxious or suffering from claustrophobia (Westbrook & Roth, 2011). A sedative during the MRI scan is generally safe, but leaves one feeling drowsy and cannot perform most activities that require high concentration, such as operating machinery or driving, for the rest of the day.

Risks of incidental findings

The high sensitivity of MRI scans can occasionally create some problems by picking up apparent abnormalities i.e. incidental findings that are not actually related to the disease being examined. Such incidental findings are likely to cause panic and make people follow unnecessary treatment, for example, surgery of the spine, which may come with other risks and costs.

Conclusions

MRI is a low-risk technology, provided that sensible safety precautions are considered to ensure that the likely benefit outweighs the possible hazards. Very few patients are allergic to the contrasting agent and rarely do patients experience side effects of using the contrast agent. The recovery period after one has been sedated is likely to take the rest of the day after the MRI scan procedure has been completed. Examination of the available literature and existing knowledge reveal that the only significant health hazard associated with MRI scans is the presence of ferromagnetic implants in the body. Since the technology came into use, there has been no evidence of biological effects to over millions of tests taken. All the risks encountered are short-term and are only experienced during the MRI scan test, or a few hours after the procedure. Unlike ionizing radiations, the technique does not alter the structure, properties and composition of atoms. The technique provides more detailed information on organs and tissues compared to other imaging techniques, such as X-ray, CT scan, or ultrasound. However, the test is associated with some intrinsic hazards that should well be understood, acknowledged and appropriately considered by both the physician and the patient before performing an MRI scanning procedure.

From these research, it is hopeful that the knowledge of MRI safety will guide future designs and also affect the selection of test procedures to guarantee safe and efficient MRI system operation.

References

Brown, M. & Semelka, R., 2011. MRI: Basic Principles and Applications. London: John Wiley & Sons.

Cherry, S., Badawi, R. & Qi, J., 2016. Essentials of In Vivo Biomedical Imaging. New York: CRC Press.

Dendy, P. P. & Heaton, B., 2011. Physics for Diagnostic Radiology. Third Edition ed. New York: CRC Press.

Kane, S. A., 2009. Introduction to Physics in Modern Medicine. 2nd Edition ed. London: Taylor & Francis.

McRobbie, D., Moore, E., Graves, M. & Prince, M., 2007. MRI from Picture to Proton. 2nd ed. London: Cambridge University Press.

Medina, S., Blackmore, C. & Kimberly, A., 2011. Evidence-Based Imaging: Improving the Quality of Imaging in Patient Care. New York: Springer Science & Business Media.

Mudry, K., Plonsey, R. & Bronzino, J., 2003. Biomedical Imaging. New York: CRC Press.

Semelka, R. & Elias, J., 2013. Health Care Reform in Radiology. London: John Wiley & Sons.

Syed, M. & Mohiaddin, R., 2012. Magnetic Resonance Imaging of Congenital Heart Disease. New York: Springer Science & Business Media.

Webb, S., 1988. The Physics of Medical Imaging. United Kingdom: CRC Press.

Weishaupt, D., Köchli, V. D. & Marincek, B., 2008. How does MRI work?: An Introduction to the Physics and Function of Magnetic Resonance Imaging. 2nd ed. New York: Springer Science & Business Media.

Westbrook, C. & Roth, C. K., 2011. MRI in Practice. 4th ed. London: John Wiley & Sons.