Purpose: The aim of this study was to develop a prototype magnetic resonance (MR)-compatible positron emission tomography (PET) that can be inserted into a MR imager and that allows simultaneous PET and MR imaging of the human brain. This paper reports the initial results of the authors' prototype brain PET system operating within a 3-T magnetic resonance imaging (MRI) system using newly developed Geiger-mode avalanche photodiode (GAPD)-based PET detectors, long flexible flat cables, position decoder circuit with high multiplexing ratio, and digital signal processing with field programmable gate array-based analog to digital converter boards.
Methods: A brain PET with 72 detector modules arranged in a ring was constructed and mounted in a 3-T MRI.
Electrooculogram (EOG) measurements, along with infrared measurements, are commonly used to record eye blinking during functional magnetic resonance imaging (fMRI). We report herein, on the use of EOG in measuring voluntary and inhibited eye blinking during echo planar imaging (EPI) in an MR scanner. The inhibited eye blinking occurred during the period, in which subjects were requested not to blink their eyes.
View Article and Find Full Text PDFChinese characters appear in the currently used Korean language, and the system used for writing system the Korean language consists of a mixture of the Korean alphabet and Chinese characters. In the present study, neural mechanisms involved in reading a single Chinese character words and naming pictures by Korean native speakers were investigated using a functional magnetic resonance imaging technique. The findings show a right hemispheric dominance within the occipito-temporal and the left middle/medial frontal area for both reading Chinese characters and naming pictures.
View Article and Find Full Text PDFNeural correlates of eye blink in healthy human subjects can be investigated using functional magnetic resonance imaging. However, the focus of most previous studies has been on intentional eye blinking. The goal of the present study was to examine the neural correlates of spontaneous eye blinking with the help of EOG measurements during data acquisition of fMRI.
View Article and Find Full Text PDFFunctional magnetic resonance imaging (fMRI) data is usually analyzed using hemodynamic response data formulated with the aid of a gamma function. An fMRI response to stimuli can be mathematically modeled by convolution of the hemodynamic response and the presented stimulus. This approach is based on a linear system analysis.
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