Dynamic models of BOLD contrast
نویسندگان
چکیده
منابع مشابه
dynamic coloring of graph
در این پایان نامه رنگ آمیزی دینامیکی یک گراف را بیان و مطالعه می کنیم. یک –kرنگ آمیزی سره ی رأسی گراف g را رنگ آمیزی دینامیکی می نامند اگر در همسایه های هر رأس v?v(g) با درجه ی حداقل 2، حداقل 2 رنگ متفاوت ظاهر شوند. کوچکترین عدد صحیح k، به طوری که g دارای –kرنگ آمیزی دینامیکی باشد را عدد رنگی دینامیکی g می نامند و آنرا با نماد ?_2 (g) نمایش می دهند. مونت گمری حدس زده است که تمام گراف های منتظم ...
15 صفحه اولOn the nature of the BOLD fMRI contrast mechanism.
Since its development about 15 years ago, functional magnetic resonance imaging (fMRI) has become the leading research tool for mapping brain activity. The technique works by detecting the levels of oxygen in the blood, point by point, throughout the brain. In other words, it relies on a surrogate signal, resulting from changes in oxygenation, blood volume and flow, and does not directly measur...
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Echo-planar imaging with gradient echo allows whole-brain images to be rapidly acquired. However, its main limitation is that magnetic field inhomogeneities in regions of the brain close to bone and air-filled sinuses result in reduced signal-to-noise ratio and signal loss. In particular this is a problem for imaging the temporal lobes, and can therefore affect the results of some language-rela...
متن کاملSimultaneous detection of changes in perfusion and BOLD contrast.
A new functional magnetic resonance imaging (fMRI) technique for simultaneous detection (SIDE) of changes in perfusion and blood oxygenation level dependent (BOLD) contrast is described. Perfusion contrast is generated by using magnetically labeled endogenous water proton spins as a freely diffusible tracer. A single slice-selective inversion pulse is combined with dual echo echo-planar imaging...
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Most functional magnetic resonance imaging (fMRI) studies are based on measuring the changes in the blood oxygenation level-dependent (BOLD) contrast that arise from a complex interplay between cerebral hemodynamics and oxidative metabolism. To separate these effects, we consecutively applied two different stimuli: visual stimulation (black/white checkerboard alternating with a frequency of 8 H...
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ژورنال
عنوان ژورنال: NeuroImage
سال: 2012
ISSN: 1053-8119
DOI: 10.1016/j.neuroimage.2012.01.012