Exploring brain function with magnetic resonance imaging (original) (raw)
Functional magnetic resonance imaging: Emerging clinical applications
Current Psychiatry Reports, 2002
Functional magnetic resonance imaging (fMRI) is a relatively new and noninvasive method of functional brain mapping. Functional MRI is increasingly being applied to the study of neuropsychiatric disorders, including schizophrenia, Alzheimer’s disease, traumatic brain injury, and others. Particularly noteworthy are findings related to plasticity in the adult human brain. Despite the promise of fMRI for improving the conceptualization, assessment, and treatment of neuropsychiatric disorders, important technical and scientific issues remain. Future research will address integrating fMRI with other emerging neuroimaging techniques.
Functional Magnetic Resonance Imaging (FMRI)
People express their mental states, including emotions, thoughts, and desires, all the time through facial expressions, vocal nuances and gestures. Functional MRI or functional Magnetic Resonance Imaging (fMRI) is a type of specialized MRI scan. It measures the haemodynamic response (change in blood flow) related to neural activity in the brain or spinal cord of humans or other animals. It is one of the most recently developed forms of neuro-imaging. Since the early 1990s, fMRI has come to dominate the brain mapping field due to its relatively low invasiveness, absence of radiation exposure, and relatively wide availability.
Functional magnetic resonance imaging and the brain: A brief review
World journal of radiology, 2017
Functional magnetic resonance imaging (fMRI) is employed in many behavior analysis studies, with blood oxygen level dependent- (BOLD-) contrast imaging being the main method used to generate images. The use of BOLD-contrast imaging in fMRI has been refined over the years, for example, the inclusion of a spin echo pulse and increased magnetic strength were shown to produce better recorded images. Taking careful precautions to control variables during measurement, comparisons between different specimen groups can be illustrated by fMRI imaging using both quantitative and qualitative methods. Differences have been observed in comparisons of active and resting, developing and aging, and defective and damaged brains in various studies. However, cognitive studies using fMRI still face a number of challenges in interpretation that can only be overcome by imaging large numbers of samples. Furthermore, fMRI studies of brain cancer, lesions and other brain pathologies of both humans and anima...
Functional imaging in neurosciences
Journal of Neuroanaesthesiology and Critical Care, 2015
Recent advances in functional imaging of the brain have enabled a better understanding of the brain functions in health and disease. Amongst various functional imaging techniques, functional magnetic resonance imaging (fMRI) has been more rigorously employed in both clinical practice and in the research arena. This review will discuss the principles and techniques of fMRI, its role in understanding the pathophysiology of brain injury and finally, its clinical application in diagnosing neurological conditions and prognostication of outcome in patients with neurological disorders.
Functional magnetic resonance imaging in neurology
… Research For Nursing, 2006
The present contribution discusses the clinical use of functional MRI (fMRI) and its role in the most common neurological diseases. FMRI was found a reliable and reproducible examination tool resulting in a wide distribution of fMRI methods in presurgical evaluation of epilepsy in determining the relationship of eloquent areas and the epileptic focus. Preliminary data suggest that fMRI using memory paradigms can predict the postoperative memory decline in epilepsy surgery by determining whether a reorganization of memory functions took place. Speech-activated fMRI became the most used tool in determining hemispheric dominance. Visual and senso-motor cortex can also be routinely investigated by fMRI which helps in decision on epilepsy surgery. FMRI combined with EEG is a new diagnostic tool in epilepsy and sleep disorders. FMRI can identify the penumbra after stroke and can provide an additional information on metabolic state of the threatened brain tissue. FMRI has a predictive role in poststroke recovery. In relapsing-remitting MS an adaptive reorganization can be demonstrated by fMRI affecting the visual, motor, and memory systems, despite preserved functional performance. Much more extensive reorganization can be demonstrated in secondary progressive MS. These findings suggest that the different stages of MS are related to different stages of the reorganization and MS becomes progressive when there is no more reserve capacity in the brain for reorganization. FMRI offers the capability of detecting early functional hemodynamic alterations in Alzheimer's disease before morphological changes. FMRI can be a valuable tool to test and monitor treatment efficacy in AD. FMRI can also provide information about the mechanisms of different therapeutic approaches in Parkinson disorder including drug treatment and deep brain stimulation.
Magnetic Resonance in Medicine, 1993
The workshop was held on behalf of the Society of Magnetic Resonance in Medicine and the Society of Magnetic Resonance Imaging. This well attended meeting (almost 280 participants, including 37 speakers), provided a forum to discuss the new role of MR in the study of brain function, from the molecular to the cognitive level. Brain perturbations such as oxygenation stresses and ischemia as well as brain activation studies were especially emphasized during focused sessions. The use of MRI together with other functional neuroimaging techniques, such as PET, EEG, or MEG, were addressed by leaders in these fields. The meeting lasted 2% days with scientific sessions from 8:OO am to 4:OO pm, and from 8:OO pm to 9:30 pm. Each session was followed by a parallel discussion to allow interactive exchanges between speakers and participants on fundamental issues. There were four sessions at this meeting: diffusion imaging, perfusion imaging, coupling between neural activity and hemodynamics, and brain activation studies. In addition, on each day, a total of 31 posters were presented by participants.
Functional Brain Imaging: A Comprehensive Survey
Functional brain imaging allows measuring dynamic functionality in all brain regions. It is broadly used in clinical cognitive neuroscience as, well as in research. It will allow the observation of neural activities in the brain simultaneously. From the beginning when functional brain imaging was initiated by the mapping of brain functions proposed by phrenologists, many scientists were asking why we need to image brain functionality since we have already structural information. Simply, their important question was including a great answer. Functional information of the human brain would definitely complement structural information, helping to have a better understanding of what is happening in the brain. This paper, which could be useful to those who have an interest in functional brain imaging, such as engineers, will present a quick review of modalities used in functional brain imaging. We will concentrate on the most used techniques in functional imaging which are functional magnetic resonance imaging (fMRI) and functional optical imaging, which is one of novelties in this area of study.
European Journal of Neuroscience, 1995
The technique of functional magnetic resonance imaging (FMRI) allows the measurement of functional cerebral blood flow changes occurring with specific tasks. However, the spatial relationship between neuronal activity and functional cerebral blood flow changes is not known yet. This study compares the centre of neuronal activation (measured by magnetoencephalography) with that of the blood flow response (measured by FMRI) to unilateral motor stimulation in eight subjects. The results show a mean localization difference of 1.6 cm and demand application of methodological improvements as recently suggested.
Functional magnetic resonance imaging: Measuring versus estimating
2007
Brain imaging techniques largely spread in neuroscience literature. Due to initial technical limitations such as the very low signal-to-noise ratio, group experiments became the rule. This fact, together with the wide use of standard brains to localize the activations, lead several experimenters to the wrong idea that the brain can be described by a Cartesian coordinate system, neglecting at the same time the importance of individual neuroanatomy. My commentary on the paper by Devlin and Poldrack reinforces their reminder that it is necessary to deal with anatomy. Moreover, it adds some considerations on the relevance of single subjects studies and on the importance of the BOLD intensity signal, which should be used to describe brain activity together with the most used statistical tools.