Seung Schik Yoo

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OBJECTIVE Previous research has noted functional and structural temporal lobe abnormalities in schizophrenia that relate to symptoms such as auditory hallucinations and thought disorder. The goal of the study was to determine whether the functional abnormalities are present in schizophrenia at early stages of auditory processing. METHOD Functional(More)
We used event-related fMRI methodology to investigate human brain activity during auditory imagery. A series of susceptibility-weighted MR images covering the whole brain were acquired to obtain blood oxygenation level-dependent (BOLD) signal changes associated with the imagery event of hearing simple monotone. Group analysis across the 12 right-handed(More)
Fourteen typically developing children from 7.9-11.3 years in age were studied with functional magnetic resonance imaging to identify the cerebral loci involved in performance of paced finger tapping by children. Each child performed two bimanual alternating paced finger-tapping tasks. In the first, paced finger tapping was conducted to external 3-Hz pacing(More)
In an investigation of a multiresolution and multistaged approach in functional MRI, the relationship between spatial resolution and detection of functional activation is examined. The difference between functional detection and mapping is defined, and a multiresolution approach to functional detection is analyzed by constructing simple theoretical and(More)
A method to visualize surface EEG electrodes on conventional high-resolution magnetic resonance (MR) images is presented. Because conventional silver or gold electrodes generate an insignificant artifactual signal signature in MR images, a plastic capsule filled with gadolinium-doped water was designed to mold onto each electrode, thereby outlining the(More)
We describe a method of interactive three-dimensional segmentation and visualization for anatomical magnetic resonance imaging (MRI) data in a personal computer environment. The visual feedback necessary during 3-D segmentation was provided by a ray casting algorithm, which was designed to allow users to interactively decide the visualization quality(More)
A new method for functional magnetic resonance imaging (fMRI) employing non-Fourier encoding using spatially selective radiofrequency (RF) excitation is presented. The method uses manipulation of spatially selective RF pulses to encode spins in the slice-select direction. The method has several advantages over standard multislice approaches. It provides a(More)
To rapidly track invasive devices within MRI systems, a novel approach using a limited projection reconstruction technique is presented. Our method exploits the difference between images reconstructed from a limited number of projections and serves to depict the tip of a needle during its advancement. This method was implemented on a standard MRI system(More)
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