Neuroimaging

Describe various neuroimaging techniques and their relative advantages and disadvantages.

ANSWER

Neuroimaging

Neuroimaging or brain scanning is a method of examining and learning the human brain in both healthy and impaired populations. The process uses various techniques that directly or indirectly images the brain’s structure, functions, or pharmacology. These methods include magnetoencephalography, positron emission tomography, and transcranial magnetic stimulation.

Magnetoencephalography (MEG)

This method depends on the logically occurring magnetic areas in all living organisms. The areas are linked with the electric currents that are part of the regular brain purpose. Since there is a change throughout the brain activities, there is also a change in the measurable magnetic regions. With this technique, it is said that the visible neuronal indicators are retrieved from dendritic movement in the pyramidal cells of the cerebral cortex. Therefore, the method effectively measures cellular operations (Tommasin et al., 2019). The approach also allows for many behavioural tests involving auditory, visual, and motor studies. Baseline evaluation with zero tasks can also examine resting brain activities. The information obtained should be processed before regions of task-related brain operations can be known. The main disadvantage of this technique is that its signals of interest are minimal. Another disadvantage of the process is that it is expensive and not as effective as fMRI at localizing where activity occurs in the brain.

Pisitron Emission Tomography

This approach uses a radioactively labelled molecule called a pisitron-emitting isotope. These isotopes range from fluorine, carbon to oxygen and nitrogen. One of the isotopes is injected into a biologically significant molecule and later gasped by the patient. It then flows to the brain areas as per the molecule’s chemistry and the brain’s metabolic and blood flow demands. Since an extensive series of molecules can be utilized, PET can measure blood flow, brain metabolism, and blood volume. Another advantage linked with the process is the variety of information retrieved with the different labelled molecules present, including O-labelled water, to study the blood flow (Wintermark et al., 2015). Since this method exposes the patient to rays, the disadvantage is that recurring scanning is not possible. This further restrains task recurrence and the presentation of several actions in the same session. With MEG, the information can be obtained in many ways, including maps of the supply of the labelled molecule.

Transcranial Magnetic Stimulation

This is an exclusive process used to examine the roles of the human brain. It uses a magnetic area to introduce electric rays in the fundamental brain tissue, thus stimulating the neurons. The approach can be used to plan brain function expound brains engaged in task performance through manipulating brain operations. Advantages include minimal side effects because the procedure is well tolerated with fewer adverse risks. The food and drug administration has also approved the technique to treat the major depressive disorder in patients who do not respond to one antidepressant (Kalavathi, Senthamilselvi & Prasath, 2017). Its success level is also practical, where various studies have concluded that patients who undergo this procedure experience reduced symptoms. On the other hand, one disadvantage of the method is that it is not for everyone since it can be complicated for some people with given conditions. It uses a magnetic field that can negatively affect people with mental implanted above their neckline. The technique is also expensive; therefore, getting an insurance cover is difficult.

References

Kalavathi, P., Senthamilselvi, M., & Prasath, V. B. (2017). Review of computational methods on brain symmetric and asymmetric analysis from neuroimaging techniques. Technologies, 5(2), 16.

Tommasin, S., Giannì, C., De Giglio, L., & Pantano, P. (2019). Neuroimaging techniques to assess inflammation in multiple sclerosis. Neuroscience, 403, 4-16.

Wintermark, M., Sanelli, P. C., Anzai, Y., Tsiouris, A. J., Whitlow, C. T., Druzgal, T. J., … & Zeineh, M. (2015). Imaging evidence and recommendations for traumatic brain injury: conventional neuroimaging techniques. Journal of the American College of Radiology, 12(2), e1-e14.