Magnetic Resonance Imaging Technology
One of the most valuable technologies that significantly benefit people is magnetic resonance imaging (MRI). The principle of operation of the MRI machine is that under the influence of radio signals, hydrogen atoms in the forehead of a person placed in a strong magnetic field resonate and give out various signals, depending on the nature of the disease. Kose (2021) states that MRI was first proposed in 1973 by Lauterbur, who presented a cross-sectional image of water protons in two test tubes by nuclear magnetic resonance.
Exceptionally clear MRI images obtained as a result of the study allow doctors to see even minimal tumors and small inflammatory processes in all tissues containing water.
Societal Impact
A three-dimensional projection of the organ under study is displayed on the computer monitor, which can be viewed in any plane – this is crucial in diagnosing several severe pathologies and determining further treatment. An MR tomograph gives results that differ significantly from the data obtained using computed tomography (CT) or X-ray. CT is focused on studying physical processes in soft tissues, and X-rays are designed to look at hard tissues, i.e., bones. MRI allows checking the chemical structure of tissues and the functioning of body systems in dynamics, which will enable to get a complete picture of the state of an organ.
Technical Background
The tomograph is a tunnel-like structure inside which a movable couch is installed on which the patient is placed. Some open-type models can take data from a vertical position — the patient can undergo the study in a sitting or standing position. The principle of operation of the MRI of open or closed type devices does not change simultaneously. The specialist controls the device remotely.
The primary mechanism is connected to the receiving equipment, which uses software to process the received signals, and translate them into graphic images. MRI makes it possible to more deeply examine the data on diseases and get a comprehensive study based on the images (Isin et al., 2016). Additional programs join hundreds of separate vivid fragments depicting organs in a section into a three-dimensional model. In addition, all images can be either printed on film or recorded on digital media — this is especially important for situations where it is necessary to monitor the dynamics of the disease and the effectiveness of therapy.
The principle of operation of the MRI is based on the features of its design. The device is a tunnel, which is essentially a powerful magnet. A magnetic field is created in it during the process, and it interacts with elementary particles in the human body. By acting on them, the magnetic pulse forces protons to emit energy. It, in turn, is captured by susceptible sensors that transform electromagnetic signals into a graphic image. The high pulse frequency makes it possible to obtain images of the thinnest slices of any organ or structure. Thanks to the work of the MRI tomograph, it becomes possible to track the minor violations of blood flow, design, size, the structure of organs, and other parameters of the body. The accumulated clinical data obtained over half a century of using MRI allows people to interpret the image characteristics with high accuracy and identify pathologies that cannot be determined using other diagnostic methods.
Diagnostic Capabilities
The way the MRI machine is arranged from the inside provides tremendous diagnostic capabilities. However, there are limitations to the implementation of this diagnostic method in several specific cases. To obtain a detailed picture, the patient needs to maintain a stationary body position during the study. Otherwise, the image may be inaccurate, which can lead to an incorrect interpretation of the results. Unfortunately, some categories of patients, for objective reasons, cannot be in this position for the entire procedure from 20 to 40 minutes. In this case, it is recommended to use medicinal sedatives or anesthesia. Today people can already talk about achievements regarding dynamic MRI, which allows assessing the key indicators of the body during movement. It will take some more time to introduce these methods into everyday medical practice.
If earlier magnetic resonance imaging was strictly prohibited for patients with vascular stents, now, in most cases, such patients are not prohibited from conducting this type of study. Magnetic resonance imaging was also contraindicated for patients with non-removable dentures. But the worst thing that can happen during the scan is that the quality of the images obtained will decrease. In patients with severe claustrophobia, MRI cannot be performed, but, if necessary, the study can be performed under anesthesia.
Development Difficulties
Difficulties in development were associated with several problems. For example, the issue of scanning people who fear confined spaces has not yet been resolved and is relevant. In addition, there were significant difficulties with working with patients who have metal structures in the body or the oral cavity. With the improvement of MRI technologies, this issue has been practically resolved. Now people with metal structures can undergo scanning.
Comparison of CT and MRI
Compared to CT, MRI conducts a deeper examination of tissues and internal organs to perform accurate, fast, and effective diagnostics of the entire human body. In comparison, CT is more focused on the study of bones and hard tissues of the body. In addition, the principle of CT is based on X-rays, which harm the body, and MRI creates a layered image of organs and tissues. Magnetic resonance imaging examines blood vessels, soft tissues, internal organs, brain, nervous system, and lymph nodes. Computed tomography helps to detect structural changes in tissues.
Magnetic resonance imaging is a safe, non-invasive method of imaging soft tissue structures. MRI cannot bring harm to the body since it has nothing to do with radiation. Open and closed tomographs are used for diagnostic examination. Grist (2019) believes that advances in MRI hardware have led to the creation of a more powerful magnetic field, which has significantly contributed to the improvement of MRI. A mobile table is fed into the tunnel-type structure on which the patient lies. Next, an electromagnetic field is created around his body, allowing for a detailed scan. The disadvantages of the procedure, which can cause discomfort and negative emotions, include acoustic noise and the need to maintain a stationary position for a long time.
MRI Upgrade
Research to improve the operation of the MRI machine has led to the fact that scientists have found a way to improve the quality of images. In recent years, MRI has evolved from conventional static imaging into multidimensional, motion-resistant, and dynamic visualization of internal organs, tissues, and surrounding vessels with high resolution (Roy et al., 2019). The image quality problem can be solved with the help of a particular substrate of metamaterials – periodic structures capable of interacting with electromagnetic radiation in an unusual way. By placing such a substrate under the patient inside an MRI scanner, it is possible to significantly increase the signal-to-noise ratio in the scanned area, which leads to a considerable increase in the device’s resolution and a reduction in scanning time (Slobozhanyuk et al., 2016). In addition, the substrate allows suppressing the electric field in the scanned area, which often leads to heating of the patient’s tissues, jeopardizing the procedure’s safety.
The duration of obtaining a standard MRI image today is also a great inconvenience for patients. In conventional MRI devices, the scan can last from 15 minutes to an hour, and throughout this period, the patient must lie still. Getting high-quality images in a shorter time will make the procedure more comfortable for the patient and, in the future, will even reduce queues in hospitals. Furthermore, the procedure does not bring physical pain, except for minor inconvenience in the form of noise for some time.
Conclusion
In conclusion, the magnetic resonance imaging device is significant and necessary for monitoring the population’s health. Its invention gave people the opportunity to obtain the most accurate research results compared to other devices. In addition, the constant work of scientists on improving the tomograph is increasingly increasing the accuracy of these results. Undoubtedly, there are some contraindications and limitations, but often this is not an unsolvable problem. The technology of magnetic resonance imaging is of great importance and brings practical benefits to people worldwide where research is available. The procedure is painless and does not harm the body. The results come quickly enough, which is also an essential factor in the treatment of certain diseases.
References
Grist, T. (2019). The next chapter in MRI: Back to the future? Radiology, 293(1), 394-395. Web.
Isin, A., Direkoglu, C. and Sah, M. (2016). Review of MRI-based brain tumor image segmentation using deep learning methods. Procedia Computer Science, 102(1), 317-324. Web.
Kose, K. (2021). Physical and technical aspects of human magnetic resonance imaging: Present status and 50 years historical review. Advances in Physics, 6(1), 1-26. Web.
Roy, C., Amerom, J., Marini, D., Seed, M. and Macgowan, C. (2019). Fetal Cardiac MRI: A review of technical advancements. Topics in Magnetic Resonance Imaging, 28(5), 235-244. Web.
Slobozhanyuk, A., Poddubny, A., Raaijmakers, A., Van den Berg, C., Kozachenko, A., Dubrovina, I., Melchakova, I., Kivshar, Y. and Belov, P. (2016). Enhancement of magnetic resonance imaging with metasurfaces. Advanced Materials, 28(9), 1832–1838. Web.