scholarly journals Assessment of Major Depressive Disorders through Neuroimaging Studies and their Treatment Methods

2021 ◽  
Vol 15 ◽  
pp. 18-28
Author(s):  
Jevetha Vijayadasan ◽  
Diksha Raghunathan ◽  
Sivakumar Rajagopal ◽  
Rahul Soangra
Keyword(s):  
Depressive Disorders ◽  
Emission Tomography ◽  
Resonance Imaging ◽  
Major Depressive ◽  
Treatment Methods ◽  
Positron Emission ◽  
Major Depressive Disorders ◽  
Magnetic Resonance Imaging Mri ◽  
The Brain ◽  
Neuroimaging Techniques

Many mental disorders are caused due to improper regulation of the brain and depression is one such. It affects both children and adults and is very common among teenagers. There are many challenges clinicians face regarding the management of this disease. These challenges have prompted the development of various neuroimaging techniques that effectively diagnose the condition. The main techniques are Magnetic resonance imaging (MRI) and Positron emission tomography (PET) which have gained momentum over the years. Advanced MRI techniques help study certain regions of the brain such as hippocampus and amygdala. Effective treatments for depression include antidepressant medications and brain stimulation techniques. Although treatments are effective for a lot of people, there is still room for improvement. This article (1) presents background on depression, its types, symptoms and risk factors; (2) elaborates the neuroimaging techniques used and reviews the various techniques adopted over the years to study depression; and (3) discusses the treatment methods that can be practised to cure depression.

scholarly journals If neuroimaging is the answer, what is the question?

1999 ◽  
Vol 354 (1387) ◽  
pp. 1283-1294 ◽  
Author(s):  
S. M. Kosslyn
Keyword(s):  
Emission Tomography ◽  
Entire System ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Coarse Scale ◽  
Use Patterns ◽  
Positron Emission ◽  
To Come ◽  
The Brain ◽  
Neuroimaging Techniques

It is unclear that we will come to a better understanding of mental processes simply by observing which neural loci are activated while subjects perform a task. Rather, I suggest here that it is better to come armed with a question that directs one to design tasks in ways that take advantage of the strengths of neuroimaging techniques (particularly positron emission tomography and functional magnetic resonance imaging). Here I develop a taxonomy of types of questions that can be easily addressed by such techniques. The first class of questions focuses on how information processing is implemented in the brain; these questions can be posed at a very coarse scale, focusing on the entire system that confers a particular ability, or at increasingly more specific scales, ultimately focusing on individual structures or processes. The second class of questions focuses on specifying when particular processes and structures are invoked; these questions focus on how one can use patterns of activation to infer that specific processes and structures were invoked, and on how processing changes in different circumstances. The use of neuroimaging to address these questions is illustrated with results from experiments on visual cognition, and caveats regarding the logic of inference in each case are noted. Finally, the necessary interplay between neuroimaging and behavioural studies is stressed.

A Review on Brain Imaging Techniques for BCI Applications

2016 ◽  
pp. 39-70
Author(s):  
Saugat Bhattacharyya ◽  
Anwesha Khasnobish ◽  
Poulami Ghosh ◽  
Ankita Mazumder ◽  
D. N. Tibarewala
Keyword(s):  
Magnetic Resonance Imaging ◽  
Positron Emission Tomography ◽  
Magnetic Resonance ◽  
Brain Imaging ◽  
Near Infrared ◽  
Emission Tomography ◽  
Resonance Imaging ◽  
Functional Near Infrared Spectroscopy ◽  
Positron Emission ◽  
The Brain

Evolution has endowed human race with the most adroit brain, and to harness its potential to the fullest the concept of brain computer interface (BCI) has emerged. One of the most crucial components of BCI is the technique of brain imaging. The first approach in the field of brain imaging was to measure the electrical and magnetic activity of the brain, the techniques being known as Electroencephalography and Magnetoencephalography. Striving for furtherance, researchers came up with another alternative known as Magnetic Resonance Imaging. But it being confined to only structural imaging, the functional aspects of brain were mapped using functional magnetic resonance imaging. A similar but comparatively newer neuroimaging modality is Functional Near Infrared Spectroscopy. Transcranial Magnetic Stimulation neuro-physiological technique is based on the principle of electromagnetic induction. Based on nuclear medicine the brain imaging technologies that are widely explored in the world of BCI are Positron Emission Tomography and Single Positron Emission Tomography.

scholarly journals Metal-Based Complexes as Pharmaceuticals for Molecular Imaging of the Liver

2019 ◽  
Vol 12 (3) ◽  
pp. 137 ◽  
Author(s):  
Julia Greiser ◽  
Wolfgang Weigand ◽  
Martin Freesmeyer
Keyword(s):  
Magnetic Resonance Imaging ◽  
Positron Emission Tomography ◽  
Metal Complexes ◽  
Imaging Technique ◽  
Imaging Modality ◽  
Emission Tomography ◽  
Resonance Imaging ◽  
Positron Emission ◽  
Magnetic Resonance Imaging Mri ◽  
Uptake Mechanisms

This article reviews the use of metal complexes as contrast agents (CA) and radiopharmaceuticals for the anatomical and functional imaging of the liver. The main focus was on two established imaging modalities: magnetic resonance imaging (MRI) and nuclear medicine, the latter including scintigraphy and positron emission tomography (PET). The review provides an overview on approved pharmaceuticals like Gd-based CA and 99mTc-based radiometal complexes, and also on novel agents such as 68Ga-based PET tracers. Metal complexes are presented by their imaging modality, with subsections focusing on their structure and mode of action. Uptake mechanisms, metabolism, and specificity are presented, in context with advantages and limitations of the diagnostic application and taking into account the respective imaging technique.

scholarly journals Imaging of brain oxygenation with magnetic resonance imaging: A validation with positron emission tomography in the healthy and tumoural brain

2016 ◽  
Vol 37 (7) ◽  
pp. 2584-2597 ◽  
Author(s):  
Samuel Valable ◽  
Aurélien Corroyer-Dulmont ◽  
Ararat Chakhoyan ◽  
Lucile Durand ◽  
Jérôme Toutain ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Positron Emission Tomography ◽  
Magnetic Resonance ◽  
High Sensitivity ◽  
Emission Tomography ◽  
Imaging Biomarker ◽  
C6 Glioma Cells ◽  
Resonance Imaging ◽  
Positron Emission ◽  
The Brain

The partial pressure in oxygen remains challenging to map in the brain. Two main strategies exist to obtain surrogate measures of tissue oxygenation: the tissue saturation studied by magnetic resonance imaging (StO2-MRI) and the identification of hypoxia by a positron emission tomography (PET) biomarker with 3-[18F]fluoro-1-(2-nitro-1-imidazolyl)-2-propanol ([18F]-FMISO) as the leading radiopharmaceutical. Nonetheless, a formal validation of StO2-MRI against FMISO-PET has not been performed. The objective of our studies was to compare the two approaches in (a) the normal rat brain when the rats were submitted to hypoxemia; (b) animals implanted with four tumour types differentiated by their oxygenation. Rats were submitted to normoxic and hypoxemic conditions. For the brain tumour experiments, U87-MG, U251-MG, 9L and C6 glioma cells were orthotopically inoculated in rats. For both experiments, StO2-MRI and [18F]-FMISO PET were performed sequentially. Under hypoxemia conditions, StO2-MRI revealed a decrease in oxygen saturation in the brain. Nonetheless, [18F]-FMISO PET, pimonidazole immunohistochemistry and molecular biology were insensitive to hypoxia. Within the context of tumours, StO2-MRI was able to detect hypoxia in the hypoxic models, mimicking [18F]-FMISO PET with high sensitivity/specificity. Altogether, our data clearly support that, in brain pathologies, StO2-MRI could be a robust and specific imaging biomarker to assess hypoxia.

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