Advantages and Disadvantages of Neuroimaging Techniques and Their Contribution to our Understanding of the Brain - Essay Example

Essay Name: University: Date: Advantages and Disadvantages of Neuroimaging techniques and their Contribution to our Understanding of the Brain Introduction Neuroimaging, according to Bigler (2013), may be described broadly as any two or three dimensional representation of someone’s central nervous system (CNS), including everything from the spine, brain as well as the neighbouring structures. Essentially, there are numerous techniques that may be utilised so as to generate images of CNS. Neuroimaging involves different techniques that fall into two categories: functional and structural imaging. In this case, structural imaging examines the brain structure and may be utilised to diagnose large-scale intracranial disease like injury as well as tumour. On the other hand, functional imaging shows the activity in particular regions of the brain through detection of changes in regional chemical composition, blood flow, metabolism as well as absorption. It may be utilised in diagnosing metabolic lesions and diseases on a finer scale, for research in cognitive and neurological psychology as well as brain-computer interfaces. There are numerous techniques for Brain Imaging; Magnetic Resonance Imaging (MRI); Computed Tomography (CT); Magnetoencephalography (MEG);  Positron Emission Tomography (PET); Functional Magnetic Resonance Imaging (fMRI); among other techniques. A new perspective is opened by such techniques with regard to the basic functions of the brain, and also provides new opportunities for early diagnosis of numerous brain-related diseases. The essay focuses the advantages and disadvantages of CT, FMRI, and PET as well as their contribution to the understanding of brain. Discussion Computed Tomography (CT) Normally, CT is utilized for detecting and localizing brain tumor, hemorrhage or trauma. CT is a neuroimaging technique whereby digital geometry processing is utilized so as to generate a 3D image of the brain interior from numerous 2D X-ray images. In the CT scan, the doctor rotates an X-ray tube around the patient with the intention of defining the targeted structures. To some extent, CT technology is the same as MRI given that the cross-sectional images generated by both techniques seem to open up the body; thus, enabling the physician to examine it from the inside. However, the CT technique utilizes X-rays while MRI utilizes radio waves and magnetic field so as to produce images. Normally, CT scans are utilized to diagnose acute stroke, examine trauma and suspected intracranial hemorrhage or subarachnoid. Besides that, CT scans are used to diagnose loss of motor or sensory function, causes of headaches as well as to find out abnormalities in areas around the brain. Due to its high-contrast resolution, Computed Tomography main advantage is its capability of separating anatomical structures at various depths in the body. Besides that, CT is fast and painless and may facilitate the diagnosis of different brain conditions. Moreover, CT can be utilized to check if a disease that was previously treated can occur again. CT scan has the ability to simultaneously record images of blood vessels, soft tissue and bone; thus, making it advantages over the normal x-rays. Due to the diagnostic ability of CT scans, they can make exploratory surgery or surgical biopsy avoidable. Despite the abovementioned advantages, CT has numerous disadvantages; for instance, they increase cancer risk, especially amongst children. CT utilizes higher radiation doses as compared to plain X-ray; thus, increasing the risks of cancer. Besides that, CT is exceedingly costly and can generate a significant financial burden, particularly for patients undergoing numerous CT checkups (Fred, 2004). In this case, individuals with no medical insurance can experience a devastating financial burden. CT scans is not recommended for expectant mothers because it pose a serious risk to the unborn baby. Positron Emission Tomography (PET) Positron emission tomography (PET) is utilised to generate 4D image of how tissues as well as organs function within the body. In this technique, a radiotracer (a small radioactive chemical dose) is injected into the blood stream; thus, traveling through the body before being absorbed by the tissues and organs being examined. A PET scanner is then used to scan the subject, whereby the energy that the tracer substance gave off is searched. The energy emissions are then converted into 3D images with the assistance of the computer. Imperatively, PET scan may be used for measuring functions such as oxygen use, blood flow as well as metabolic activity. Using this data, physicians may identify abnormalities in the brain. PET imaging has a number of advantages: for instance, its capability to examine the body function by means of biochemical functions indicate that the technique detects disease prior to changes within the anatomy becoming ostensible. This makes it more successful in diagnosis of brain problems as compared to other imaging tests. Furthermore, PET imaging can be utilized as an alternative to exploratory surgeries in determining the extent at which the disease has spread. PET imaging ability to differentiate between cancerous and on-cancerous tumors make it the most precise medical tool capable of reducing the number of needless surgeries carried out because of staging data and incorrect diagnosis. In spite of the numerous advantages of PET imaging, it also has numerous disadvantages, which include: the PET imaging has risks because of the radioactive component, which makes it unsuitable for pregnant patients or those breast feeding. Besides that, the radioactive exposure in this technique signifies that the number of times that a patient can undergo this procedure is limited. Akin to CT imaging, PET imaging is exceedingly expensive; it cost between 900 and 1400 US dollars per session. Functional Magnetic Resonance Imaging (fMRI) Functional magnetic resonance imaging (fMRI) as described by Glover (2012) is a neuroimaging technique that generates activation ‘maps’ showing parts of the brain involved in a certain mental process. Normally, when a particular are of the brain is more active, it need more oxygen; therefore, the flow of oxygenated blood increases within the active area so as to meet the increased demand for oxygen. Given that the deoxygenated as well as oxygenated blood interacts in a different way with magnetic fields, brain activity may be detected through a scanner having a magnetic field. The detailed image brain appears as a data, showing the active regions during a particular mental function. Besides that, numerous images may be taken over time so as to exhibit change all through a specific duration. According to Bowman (2014), hemoglobin becomes diamagnetic after being oxygenated as well as paramagnetic after being deoxygenated. Normally, the MR scanner generates BOLD (blood oxygenated level dependent) signals, which differ based on the level of oxygenation. Therefore, fMRI may be utilised to generate localized brain activity’s distributed maps. Additionally, fMRI provides numerous advantages as compared to other types of neuroimaging. Imperatively, fMRI do not utilise radioactive isotopes; therefore, it is considered to be safer. Moreover, fMRI is non-invasive, its image resolution is outstanding, and is somewhat easy to utilise. The fMRI records on a spatial resolution making it higher as compared to other techniques. The technique has the ability to reveal the whole network of brain areas that are engaged when certain tasks are undertaken by the subjects. Akin to other discussed techniques, fMRI has a number of disadvantages; for instance, the BOLD signal only measures the neural activity indirectly; therefore, it is vulnerable to effects of non-neural body changes. Even though fMRI spatial resolution is very good, the blood supply temporal response is poor in relation to the electrical signals, which defines the neuronal communication. This poor resolution is essentially because of the measured phenomena and not due to the technique. Principles of Functional Neuroimaging In contrast to structural imaging, functional imaging focuses on showing physiological activities in a particular organ or tissue through medical image modalities, which normally uses probes or tracers so as to reflect their spatial distribution in the body. In view of this, spatial resolution is concerned with how accurately the brain activity area can be identified while temporal resolution is concerned with how accurately the time of brain activity can be identified. Normally, spatial resolution is measured by voxels. Larger voxels are used for full-brain examination while smaller sizes are used for examination focussing on certain regions of interest. On the other hand, temporal resolution as mentioned above is the smallest period of time of neural activity dependably separated through fMRI. Conclusion In conclusion, the essay has focused on the advantages and disadvantages of CT, FMRI, and PET as well as their contribution to the understanding of brain. Hitherto, much of what is understood concerning the functions of different areas of the brain is sourced from the human’s neuropsychological studies. Neuroimaging techniques are somewhat disadvantageous because they are unable to show the brain region necessity for a particular cognitive process. Still, neuroimaging techniques show that humans devoid of neurologic damage can regularly use this region to carry out specific tasks. Furthermore, neuroimaging techniques enable one to compare activation levels on different people and can show hoe greater activation in areas of brain areas related to better task performance. Furthermore, neuroimaging techniques facilitate identification of the entire neural circuit that underlies the cognitive process. As discussed in the essay, neuroimaging techniques allows for the examination of role of certain region of human brain in cognition even without accessing a specific group of patients. References Bigler, E. D. (2013). Neuroimaging I: Basic Science. New York: Springer Science & Business Media. Bowman, F. D. (2014). Brain Imaging Analysis. Annual Review of Statistics and Its Application, 1, 61–85. Fred, H. L. (2004). Drawbacks and Limitations of Computed Tomography. Texas Heart Institute journal , 31(4), 345–348. Glover, G. H. (2012). Overview of Functional Magnetic Resonance Imaging. Neurosurgery Clinics of North America, 22(2), 133–139. Read More

In this case, individuals with no medical insurance can experience a devastating financial burden. CT scans is not recommended for expectant mothers because it pose a serious risk to the unborn baby. Positron Emission Tomography (PET) Positron emission tomography (PET) is utilised to generate 4D image of how tissues as well as organs function within the body. In this technique, a radiotracer (a small radioactive chemical dose) is injected into the blood stream; thus, traveling through the body before being absorbed by the tissues and organs being examined.

A PET scanner is then used to scan the subject, whereby the energy that the tracer substance gave off is searched. The energy emissions are then converted into 3D images with the assistance of the computer. Imperatively, PET scan may be used for measuring functions such as oxygen use, blood flow as well as metabolic activity. Using this data, physicians may identify abnormalities in the brain. PET imaging has a number of advantages: for instance, its capability to examine the body function by means of biochemical functions indicate that the technique detects disease prior to changes within the anatomy becoming ostensible.

This makes it more successful in diagnosis of brain problems as compared to other imaging tests. Furthermore, PET imaging can be utilized as an alternative to exploratory surgeries in determining the extent at which the disease has spread. PET imaging ability to differentiate between cancerous and on-cancerous tumors make it the most precise medical tool capable of reducing the number of needless surgeries carried out because of staging data and incorrect diagnosis. In spite of the numerous advantages of PET imaging, it also has numerous disadvantages, which include: the PET imaging has risks because of the radioactive component, which makes it unsuitable for pregnant patients or those breast feeding.

Besides that, the radioactive exposure in this technique signifies that the number of times that a patient can undergo this procedure is limited. Akin to CT imaging, PET imaging is exceedingly expensive; it cost between 900 and 1400 US dollars per session. Functional Magnetic Resonance Imaging (fMRI) Functional magnetic resonance imaging (fMRI) as described by Glover (2012) is a neuroimaging technique that generates activation ‘maps’ showing parts of the brain involved in a certain mental process.

Normally, when a particular are of the brain is more active, it need more oxygen; therefore, the flow of oxygenated blood increases within the active area so as to meet the increased demand for oxygen. Given that the deoxygenated as well as oxygenated blood interacts in a different way with magnetic fields, brain activity may be detected through a scanner having a magnetic field. The detailed image brain appears as a data, showing the active regions during a particular mental function. Besides that, numerous images may be taken over time so as to exhibit change all through a specific duration.

According to Bowman (2014), hemoglobin becomes diamagnetic after being oxygenated as well as paramagnetic after being deoxygenated. Normally, the MR scanner generates BOLD (blood oxygenated level dependent) signals, which differ based on the level of oxygenation. Therefore, fMRI may be utilised to generate localized brain activity’s distributed maps. Additionally, fMRI provides numerous advantages as compared to other types of neuroimaging. Imperatively, fMRI do not utilise radioactive isotopes; therefore, it is considered to be safer.

Moreover, fMRI is non-invasive, its image resolution is outstanding, and is somewhat easy to utilise. The fMRI records on a spatial resolution making it higher as compared to other techniques. The technique has the ability to reveal the whole network of brain areas that are engaged when certain tasks are undertaken by the subjects. Akin to other discussed techniques, fMRI has a number of disadvantages; for instance, the BOLD signal only measures the neural activity indirectly; therefore, it is vulnerable to effects of non-neural body changes.

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