الفهرس 
Functional Magnetic Resonance Imaging (FMRI)Only 14 pages are availabe for public view
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Abstract
Functional magnetic resonance imaging (fMRI) is an imaging technique that plays an important role in determining brain functions. Also, fMRI uses this technology to identify regions of the brain where blood vessels are expanding, chemical changes are taking place, or extra oxygen is being delivered. As a patient performs a particular task, the metabolism will increase in the brain area responsible for that task, changing the signal in the magnetic resonance imaging (MRI) image. So by performing specific tasks that correspond to different functions, scientists can locate the part of the brain that governs that function. It is most used by neuroscientists and psychiatrists.
Rationale of our study was overviewed of the current status of fMRI results obtained in neurological, psychiatric and developmental disorders and some other important clinical conditions are given. The aim of our study was focused on the role of fMRI in mapping normal brain function, monitoring sensory, motor, and cognitive alteration associated with neurological insult and how entire neural networks are altered in the context of brain injury and to investigate brain activity associated with the internal monitoring of performance.
Functional fMRI is a class of imaging methods developed in order to demonstrate regional, time-varying changes in brain metabolism. These metabolic changes can be consequent to task-induced cognitive state changes or the result of unregulated processes in the resting brain. Blood Oxygen Level Dependent (BOLD) fMRI depicts changes in deoxyhemoglobin concentration consequent to task-induced or spontaneous modulation of neural metabolism. Since its inception in 1990, this method has been widely employed in thousands of studies of cognition for clinical applications such as surgical planning, for monitoring treatment outcomes, and as a biomarker in pharmacologic and training programs. More recently, attention is turning to the use of pattern classification and other statistical methods to draw increasingly complex inferences about cognitive brain states from fMRI data.
Functional MRI brain mapping has been used in research as well as clinical situations for many purposes. It can help provide basic information about brain disease, help determine and guide treatment, and monitor treatment outcomes.
Mapping sensorimotor, visual, language and memory function using fMRI can identify the eloquent cortex and predict postoperative deficits of specific functions during the presurgical workup of patients with epilepsy. In selected patients with frequent interictal epileptiform discharges, EEG-correlated fMRI has the potential to identify the cortical areas involved in generating the discharges. Better and better techniques are slowly evolving to solve challenges in clinical fMRI. With the availability of higher Tesla magnets, faster sequences, and better paradigms and postprocessing tools, the clinical application of this technique in patients with epilepsy is going to increase in the years to come.
Resting state networks and their modification by disease conditions such as Alzheimer’s, depression and other psychiatric disorders are gaining attention. However, there is growing awareness that these networks may be much more complex in their spatio-temporal dynamics than previously thought, and much more work is indicated to understand their role and utility in predicting individual behavior/physiology.
Finally, feedback derived from real-time fMRI has been shown to allow subjects to learn pain-reduction strategies, enhance sensorimotor control and to control relevant brain regions in mood disorder experiments.
After a stroke, the brain demonstrates a dynamic process beginning at the individual neuron and groups of related cells and involving both the ipsilateral and contralateral hemispheres. The process of neuroplasticity appears to be time- and local-dependent, conscripting many cell types, including neural progenitors. There is appreciation of these mechanisms through imaging, electrophysiology, and basic science is an opportunity to identify and explore therapeutic windows. Hopefully, as our knowledge expands, a clearer identification of stroke sites, the processes that evolve, and the critical epochs for specific treatments will enable clinicians to target cell types and chemicals to maximize short- and longterm functional gains.
Novel motor-skill training should be advocated upon the first presentation of pain symptoms so as to reduce the risk of further and unfavorable neuroplastic changes that are known to occur in association with pain. Slowly increasing the complexity of the novel motor-skill task over the duration of rehabilitation training may encourage cognitive effort and enhance the cortical neuroplastic changes that are known to occur in association with novel motorskill acquisition.
Rehabilitation efforts that attempt to maximize the extent of cortical neuroplastic changes stand to provide the greatest potential for rehabilitation success. Clinical and experimental findings suggest that quality motor-skill training that encourages cognitive effort should be performed with a limited number of task-repetitions such that fatigue and pain are minimized in order to optimize the outcome of rehabilitation of patients with musculoskeletal pain.