Learn More
PURPOSE To quantify measurement uncertainties of fractional anisotropy, mean diffusivity, and principal eigenvector orientations in human diffusion tensor imaging (DTI) data acquired with common clinical protocols using a wild bootstrap analysis, and to establish optimal scan protocols for clinical DTI acquisitions. MATERIALS AND METHODS A group of 13(More)
BACKGROUND Alzheimer's disease (AD) is associated with changes in cerebral white matter (WM), but the functional significance of such findings is not yet established. We hypothesized that diffusion tensor imaging (DTI) might reveal links between regional WM changes and specific neuropsychologically and psychophysically defined impairments in early AD. (More)
OBJECTIVE Alzheimer's disease (AD) is a serious neurodegenerative disorder characterized by deficits of working memory, attention, language and many other cognitive functions. Although different stages of the disease are relatively well characterized by clinical criteria, stage-specific pathological changes in the brain remain relatively poorly understood,(More)
Diffusion kurtosis imaging (DKI) is a new diffusion magnetic resonance imaging (MRI) technique to go beyond the shortages of conventional diffusion tensor imaging (DTI) from the assumption that water diffuse in biological tissue is Gaussian. Kurtosis is used to measure the deviation of water diffusion from Gaussian model, which is called non-Gaussian, in(More)
Objective. To find the location where the human brain cognitive function impairs under hypoxia. Method. 14 healthy males, aged 18-20 years, performed auditory Oddball test of two different intensities (55 dB, 80 dB) during exposure to 5000 m by breathing low oxygen mixture. EEG and Reaction Time (RT) were recorded. P3, the component of ERP, was extracted(More)
OBJECTIVE To evaluate non-Gaussian diffusion changes of the whole-brain and its correlation with cognitive performance in patients with early Alzheimer's disease (AD), using diffusion kurtosis imaging (DKI). METHODS Twenty-six patients with early AD and twenty-six normal controls underwent diffusion imaging. Seven parametric maps were calculated from(More)
OBJECTIVES To explore the changes of glutamate-glutamine (Glx) and gamma-aminobutyric acid (GABA) in the brain in normal old age and cognitive impairment using magnetic resonance spectroscopy (MRS). METHODS Seventeen normal young controls (NYC), 15 normal elderly controls (NEC), 21 patients with mild cognitive impairment (MCI) and 17 with Alzheimer(More)
A new approach to extracting single-trail event-related potential(ERP) in combination with the correlation analysis has been proposed. This approach, called time-frequency filter, is based on the concept that multiresolution wavelet transforms. At first, an investigation of the properties in time and frequency domain was carried out on the ERP. On the basis(More)
OBJECTIVE To investigate the effects of mild and moderate hypoxia on event-related potentials (ERP), and to compare the sensitivity of different stimulus paradigms to hypoxia. METHODS Twelve subjects performed visual Oddball and memory set size (MSET) 1 and MSET 3 of Sternberg tasks on the ground and at the simulated altitudes of 2500 m and 4300 m by(More)