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An improved echo planar high-speed imaging technique using spiral scan is presented and experimental advantages are discussed. This proposed spiral-scan echo planar imaging (SEPI) technique employs two linearly increasing sinusoidal gradient fields, which results in a spiral trajectory in the spatial frequency domain (k-domain) that covers the entire(More)
We hypothesized that individual differences in intelligence (Spearman's g) are supported by multiple brain regions, and in particular that fluid (gF) and crystallized (gC) components of intelligence are related to brain function and structure with a distinct profile of association across brain regions. In 225 healthy young adults scanned with structural and(More)
OBJECTIVE To investigate anatomical changes in the substantia nigra (SN) of Parkinson disease (PD) patients with age-matched controls by using ultra-high field magnetic resonance imaging (MRI). METHODS We performed 7T MRI in 10 PD and 10 age-matched control subjects. Magnetic resonance images of the SN were obtained from a 3-dimensional (3D)(More)
OBJECT A challenge associated with deep brain stimulation (DBS) in treating advanced Parkinson disease (PD) is the direct visualization of brain nuclei, which often involves indirect approximations of stereotactic targets. In the present study, the authors compared T2*-weighted images obtained using 7-T MR imaging with those obtained using 1.5- and 3-T MR(More)
MR acoustic, or sound, noise due to gradient pulsing has been one of the problems in MRI, both in patient scanning as well as in many areas of psychiatric and neuroscience research, such as brain fMRI. Especially in brain fMRI, sound noise is one of the serious noise sources that obscures the small signals obtainable from the subtle changes occurring in(More)
Real-time functional MRI (rtfMRI) has been used as a basis for brain-computer interface (BCI) due to its ability to characterize region-specific brain activity in real-time. As an extension of BCI, we present an rtfMRI-based brain-machine interface (BMI) whereby 2-dimensional movement of a robotic arm was controlled by the regulation (and concurrent(More)
Acoustic or sound noise due to gradient pulsing has been one of the problems in magnetic resonance imaging (MRI), both in patient scanning as well as in many areas of psychiatric and neuroscience research such as functional MRI. Our recent observations in functional MRI for the visual and motor cortex show very different results with sound noise in(More)
Parkinson's disease (PD) is a neurodegenerative disorder resulting from progressive loss of dopaminergic neurons in the substantia nigra (SN) pars compacta. Therefore, imaging of the SN has been regarded to hold greatest potential for use in the diagnosis of PD. At the 7.0T magnetic resonance imaging (MRI), it is now possible to delineate clearly the shapes(More)
BACKGROUND Noninvasive magnetic resonance angiography using ultra-high-field magnetic resonance imaging has recently provided us with the potential to image cerebral microvascular structures such as the lenticulostriate arteries. However, most studies using ultra-high-field magnetic resonance angiography have been limited to the visualisation of(More)