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Search Results: 1 - 10 of 10633 matches for " Functional Imaging "
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An fMRI Study of Words Processing in Chinese Language  [PDF]
Pei Xu, Bing Sun, Chunqi Chang, Nan Hu
Journal of Biosciences and Medicines (JBM) , 2016, DOI: 10.4236/jbm.2016.43002
Abstract:

Using the blood oxygen levels dependent technology of magnetic resonance imaging (BLOD-fMRI), we aimed to explore the brain activation after visual stimulation by Chinese words. In the current study, 24 healthy volunteers (12 males, 12 females, right-handed, mean age 26 ± 2 years) were prospectively included. The event related design was used in the current fMRI study when participants silently read all words appearing in the middle of the screen. Images were processed with Statistical Parametric Mapping 8 (SPM8) software, by using a general linear model (GLM). Group activations were extracted from the 2nd level group analysis with a threshold of p < 0.001, and it was shown that the main activated areas by silent reading tasks were regions involved in brain semantic processing, including middle temporal gyrus, fusiform gyrus, supplementary motor area, inferior frontal gyrus, cingulate gyrus, superior parietal lobule and inferior parietal lobule. It was also learnt that superior parietal lobule and middle temporal gyrus are related with semantic understanding, lenticular nucleus are related with semantic processing. This means, in addition to the cerebral cortex, subcortical nuclei is also very important to the processing of words in Chinese language.

Functional brain imaging with use of a new and powerful neuroimaging technique  [PDF]
Mohammad Karimi Moridani
Journal of Biomedical Science and Engineering (JBiSE) , 2009, DOI: 10.4236/jbise.2009.23029
Abstract: Most of the information available on the human brain came from subjects who had sustained major head wounds, or who suffered from various mental disorders. By determining the extent of brain damage, and the nature of the loss of function, it was possible to infer which regions of the brain were responsible for which function. With the development of the imaging techniques of computerised tomography (CT) and magnetic resonance imaging it was possi-ble to be more specific as to the location of damage in brain injured patients. The meas-urement of the electrical signals on the scalp, arising from the synchronous firing of the neu-rons in response to a stimulus, known as elec-troencephalography (EEG), opened up new possibilities in studying brain function in nor-mal subjects. However it was the advent of the functional imaging modalities of positron emis-sion tomography (PET), single photon emission computed tomography (SPECT), functional magnetic resonance imaging (fMRI), and mag-netoencephalography (MEG) that led to a new era in the study of brain function. In this paper the mechanisms of the techniques mentioned above are outlined, together with an assess-ment of their strengths and weaknesses. Then an introduction to the Metabolism and Blood Flow in the Brain is given. This is followed by a more detailed explanation of functional MRI and how such experiments are performed.
Technological Progress in Radiation Therapy for Brain Tumors  [PDF]
Frederik Jozef Vernimmen, Kathy Rock
Journal of Cancer Therapy (JCT) , 2014, DOI: 10.4236/jct.2014.51005
Abstract:

To achieve a good therapeutic ratio the radiation dose to the tumor should be as high as possible with the lowest possible dose to the surrounding normal tissue. This is especially the case for brain tumors. Technological advancements in diagnostic imaging, dose calculations, and radiation delivery systems, combined with a better understanding of the pathophysiology of brain tumors have led to improvements in the therapeutic results. The widely used technology of delivering 3-D conformal therapy with photon beams (gamma rays) produced by Linear Accelerators has progressed into the use of Intensity modulated radiation therapy (IMRT). Particle beams have been used for several decades for radiotherapy because of their favorable depth dose characteristics. The introduction of clinically dedicated proton beam therapy facilities has improved the access for cancer patients to this treatment. Proton therapy is of particular interest for pediatric malignancies. These technical improvements are further enhanced by the evolution in tumor physiology imaging which allows for improved delineation of the tumor. This in turn opens the potential to adjust the radiation dose to maximize the radiobiological effects. The advances in both imaging and radiation therapy delivery will be discussed.

Funkciono MR snimanje u detekciji elokventnih mo danih zona
?veljo O.B.,Koprivek K.M.,Lu?i? M.A.,Markovi? ?.
Acta Chirurgica Iugoslavica , 2007, DOI: 10.2298/aci0703039s
Abstract: Functional magnetic resonance imaging - fMRI is a relative new magnetic resonance technique that may be used for identification of eloquent cortical areas. Gold standard for detection of eloquent areas that should be preserved subsequent to resection is a direct cortical stimulation, which is invasive and frequently difficult to be performed. On the other hand, fMRI has proved to be a promising alternative with good time and spatial resolution. The paper explains the method of the functional MR imagining, origins of the signal and its relation to the neuronal activation. fMRI technique is illustrated by the example of the motor cortex identification. Functional Magnetic Resonance Imaging - fMRI is a relatively new MR application that can be used for detection of eloquent areas of the brain. The gold standard for identifying eloquent areas of the brain to be avoided in resections is direct cortical stimulation, which is an invasive and difficult procedure. On the other hand fMRI shows great promise as noninvasive alternative to invasive brain mapping with good temporal and spatial resolution. This paper introduces the technique of fMRI, explain the origin of the signal and his connections with neural activations. An illustrative example of a motor activation study is described.
Cost Analysis of Diffusion Tensor Imaging and MR Tractography of the Brain  [PDF]
Christopher Hancock, Byron Bernal, Camila Medina, Santiago Medina
Open Journal of Radiology (OJRad) , 2014, DOI: 10.4236/ojrad.2014.43034
Abstract: Purpose: To determine the total direct costs (fixed and variable costs) of diffusion tensor imaging (DTI) and MR tractography reconstruction of the brain. Materials and Methods: The direct fixed and variable costs of DTI with MR tractography were determined prospectively with time and motion analysis in a 1.5-Tesla MR scanner using 15 encoding directions. Seventeen patients with seizure disorders, 9 males & 8 females, with mean age of 13 years (age range 2 - 33 years) were studied. Total direct costs were calculated from all direct fixed and variable costs. Sensitivity analyses between 1.5 versus a 3-Tesla MR system, and 15 versus 32 encoding directions were done. Results: The total direct costs of DTI and MR tractography for a 1.5-T system with 15 encoding directions were US $97. Variable cost was $76.80 and fixed cost was $20.20. Total direct costs for a 3-T system with 15 directions decreased to US $94.5 because of the shorter scan time despite the higher cost of the 3-T system. The most costly component of the direct cost was post-processing analysis at US $46.00. Conclusion: DTI with MR tractography has important total direct costs with variable costs higher than the fixed costs. The post processing variable cost is the most expensive component. Developing more accurate automated post-processing software for DTI and MR tractography is important to decrease this variable labor cost. Given the added value of DTI-MR tractography and the costs involved reimbursement codes should be considered.
Magnetoencephalography Coherence Source Imaging in Dyslexia: Activation of Working Memory Pathways  [PDF]
Alfred Mansour, Susan M. Bowyer, Annette E. Richard, John E. Moran, Laszlo A. Erdodi, Amy Olszewski, Lesley Pawluk, Daniel Jacobson, Kelly Vogt, Aimee M. Moore, Renée L ajiness-O’Neill
Psychology (PSYCH) , 2014, DOI: 10.4236/psych.2014.516193
Abstract: This study investigates the functional connectivity of neuronal networks critical for working memory in individuals with dyslexia by means of magnetoenchephalographic (MEG) coherence imaging. Individuals with dyslexia showed an early onset of activation in anterior cortical regions (precentral gyrus and the superior frontal gyrus), which differed from controls where activation initiated in posterior cortical regions (supramarginal gyrus and superior temporal gyrus). Further, individuals with dyslexia showed lower brain activity in the right superior temporal gyrus and right middle temporal gyrus than controls during a spatial working memory (SWM) task. In contrast, during a verbal working memory (VWM) task, individuals with dyslexia showed lower activity in the right insular cortex and right superior temporal gyrus and higher, likely compensatory, activity in the right fusiform gyrus, left parahippocampal gyrus, and left precentral gyrus. When performing a SWM task, individuals with dyslexia showed significantly lower coherent activity and synchronization in 1) right frontal connectivity, 2) right fronto-temporal connectivity, 3) left and right frontal connectivity, 4) left temporal and right frontal connectivity, and 5) left occipital and right frontal connectivity. MEG coherence source imaging (CSI) by frequency bands showed lower mean coherence values in individuals with dyslexia compared to controls for each frequency range during the SWM task. In contrast, during the VWM task, individuals with dyslexia showed higher coherent low frequency (3 - 15 Hz) and lower coherent high frequency (30 - 45 Hz) synchronization than control subjects. Logistic regression of coherent activity by group membership was significant, with an overall predictive success of 84.4% (88.9% for controls and 77.8% for dyslexia). Coherence between the right lateral orbitofrontal and middle orbitofrontal gyri pair substantially contributed to group membership. The results suggest a pattern of aberrant connectivity as evidenced by the early onset and reliance on prefrontal cortical areas, the differential activation of fronto-temporal brain systems, and an altered pattern of functional connectivity in the frontotemporal pathways mediating these behaviors.
Brain Mechanisms of College Students’ Social Adjustment: Evidence from Multimodal Magnetic Resonance Imaging (MRI)  [PDF]
Ying Ge, Weigang Pan, Tin Wang
Health (Health) , 2018, DOI: 10.4236/health.2018.104036
Abstract: This study investigated the neural basis of social adjustment using multimodal brain imaging and social-adjustment measurements to analyze functional and structural brain features during social adjustment in college students. The results showed that, regarding brain function, some dimensions of social adjustment were associated with the insula, and some regions of the frontal and occipital lobes. Self-adjustment and satisfaction required activation of the middle frontal gyrus, while career adjustment and academic adjustment required inhibition of the inferior frontal gyrus and lingual gyrus, respectively. Decreased metabolic activity of the lingual gyrus was beneficial for obtaining satisfaction. Regarding brain structure, the total score and some dimensions of social adaptation were associated with the gray matter of portions of the temporal and parietal lobes. The superior temporal gyrus was associated with the total social adjustment and satisfaction score, the middle temporal gyrus with campus-life adjustment and satisfaction, and the post central gyrus and the inferior parietal lobule with emotional adjustment. The changes in the gray matter volume of these brain regions to a certain extent reflected socially adaptive behaviors. The results suggest that social adaptability is associated with various brain regions dispersed among both hemispheres of the brain, and requires synergistic inter-actions between multiple brain regions and both brain hemispheres.
Diagnostic imaging of lying [Obrazowanie diagnostyczne k amstwa]
Lass, Piotr,S?awek, Jaros?aw,Sitek, Emilia,Szurowska, Edyta
Psychiatria Polska , 2013,
Abstract: Functional diagnostic imaging has been applied in neuropsychology for more than two decades. Nowadays, the functional magnetic resonance (fMRI) seems to be the most important technique. Brain imaging in lying has been performed and discussed since 2001. There are postulates to use fMRI for forensic purposes, as well as commercially, e.g. testing the loyalty of employees, especially because of the limitations of traditional polygraph in some cases. In USA fMRI is performed in truthfulness/lying assessment by at least two commercial companies. Those applications are a matter of heated debate of practitioners, lawyers and specialists of ethics. The opponents of fMRI use for forensic purposes indicate the lack of common agreement on it and the lack of wide recognition and insufficient standardisation. Therefore it cannot serve as a forensic proof, yet. However, considering the development of MRI and a high failure rate of traditional polygraphy, forensic applications of MRI seem to be highly probable in future.
Brain activation patterns associated with sexual orientation in homosexual male and female: a case study with 3.0T fMRI  [PDF]
Gwang-Won Kim, Gwang-Woo Jeong, Jong-Chul Yang
Journal of Biomedical Science and Engineering (JBiSE) , 2011, DOI: 10.4236/jbise.2011.43027
Abstract: This study was performed to clarify the sexual orien-tation in a 19-year-old homosexual male and a 20-year-old homosexual female by using a functional magnetic resonance imaging (fMRI) with viewing male and female erotic nude pictures. The sex hor-mone levels of the homosexual male and female were in the normal range of healthy heterosexual males and females, respectively. In both homosexuals more significant brain activities were observed while view-ing the nude pictures of the same genetic sex than those of the opposite sex in the frontal cortex, parietal cortex, occipital cortex, anterior cingulate gyrus, amygdala, midbrain, hippocampus, orbitofrontal cortex, parahippocampal gyrus, thalamus, globus pallidus, and putamen, which are known to be re-sponsive to sexual arousal. The homosexual male and female showed a tendency toward higher sexual arousal to the same genetic sex as comparison with the opposite sex. This finding may be useful to un-derstand the different neural mechanisms on sexual arousal in homosexuals.
Investigating connectional characteristics of Motor Cortex network  [PDF]
Dong-Mei Hao, Ming-Ai Li
Journal of Biomedical Science and Engineering (JBiSE) , 2009, DOI: 10.4236/jbise.2009.21006
Abstract: To understand the connectivity of cerebral cor-tex, especially the spatial and temporal pattern of movement, functional magnetic resonance imaging (fMRI) during subjects performing finger key presses was used to extract functional networks and then investigated their character-istics. Motor cortex networks were constructed with activation areas obtained with statistical analysis as vertexes and correlation coefficients of fMRI time series as linking strength. The equivalent non-motor cortex networks were constructed with certain distance rules. The graphic and dynamical measures of motor cor-tex networks and non-motor cortex networks were calculated, which shows the motor cortex networks are more compact, having higher sta-tistical independence and integration than the non-motor cortex networks. It indicates the motor cortex networks are more appropriate for information diffusion.
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