Keh-Shih Chuang

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Group independent component analysis (gICA) was performed on resting-state data from 14 healthy subjects scanned on 5 fMRI scan sessions across 16 days. The data were reduced and aggregated in 3 steps using Principal Components Analysis (PCA, within scan, within session and across session) and subjected to gICA procedures. The amount of reduction was(More)
Micro positron emission tomography (PET) and micro single-photon emission computed tomography (SPECT), used for imaging small animals, have become essential tools in developing new pharmaceuticals and can be used, among other things, to test new therapeutic approaches in animal models of human disease, as well as to image gene expression. These imaging(More)
The localization of the sympathetic postganglionic neurons innervating the cardiac coronary arteries of the cat was investigated using retrograde axonal transport with horseradish peroxidase. We found after the enzyme was applied to the main trunk of the right coronary artery, and to the main trunk and the terminal branch of the ventral descending vessels(More)
To present a pseudo lossless compression which modifies the noise component of the bit data to enhance the compression without affecting image quality? The hypothesis behind the study is that the bit data contaminated by noise can be manipulated without affecting image quality. The compression method comprises of three steps: (1) to estimate the noise level(More)
Previous studies have shown that Joint Photographic Experts Group (JPEG) 2000 compression is better than JPEG at higher compression ratio levels. However, some findings revealed that this is not valid at lower levels. In this study, the qualities of compressed medical images in these ratio areas ( approximately 20), including computed radiography, computed(More)
The significance of each bit of the pixel in digital image data from various radiological modalities is tested to determine the contrast resolution. Two statistical methods, join-count statistic and chi-square goodness of fit test, are used to perform the test. Join-count statistic is used to measure the spatial coherence among pixels, while the chi-square(More)
This paper presents a new class of image noise smoothing algorithms utilizing the membership information of the neighboring pixels. The basic idea of this method is to compute the smoothed output using neighboring pixels from the same cluster to avoid image blurring. A fuzzy c-means algorithm is first applied to the image to separate the image pixels into a(More)
To perform unilateral or bilateral upper thoracic ganglionectomy, we established a three-dimensional system of coordinates for T2 and T3 ganglia. For this purpose, the spatial relations were represented by drawings obtained from 50 Chinese cadavers. A simple stereotactic frame was constructed as an aid in performing the procedure. Then, according to the(More)
The localization of the sympathetic postganglionic neurons innervating the cat heart has been investigated by using retrograde axonal transport of horseradish peroxidase (HRP). HRP was injected into the subepicardial layers of 4 different cardiac regions. The animals were sacrificed 72-96 h later and fixed by perfusion via the left ventricle. The(More)
OBJECT Cellular density is a major factor responsible for changes in apparent diffusion coefficients (ADCs). The authors hypothesized that loss of tumor cells after Gamma Knife surgery (GKS) might alter ADC values. Magnetic resonance imaging, including diffusion-weighted (DW) imaging, was performed to detect cellular changes in brain tumors so that the(More)