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Your search keyword '"Lin, Chao-Chun"' showing total 3 results
Start Over Author "Lin, Chao-Chun" Publisher elsevier b.v.
3 results on '"Lin, Chao-Chun"'

1. Concordance correlation coefficients estimated by variance components for longitudinal normal and Poisson data.

Author

Tsai, Miao-Yu and Lin, Chao-Chun

Subjects
*STATISTICAL correlation, *ANALYSIS of variance, *PARAMETER estimation, *LONGITUDINAL method, *POISSON regression
Abstract

The concordance correlation coefficient (CCC) is widely used to assess agreement between two observers for continuous responses. Further, the CCC is extended for measuring agreement with discrete data. This paper proposes a variance components (VC) approach that allows dependency between repeated measurements over time to assess intra-agreement for each observer and inter- and total agreement among multiple observers simultaneously under extended three-way generalized linear mixed-effects models (GLMMs) for longitudinal normal and Poisson data. Furthermore, we propose a weight matrix to compare with existing weight matrices. Simulation studies are conducted to compare the performance of the VC, generalized estimating equations and U -statistics approaches with different weight matrices for repeated measurements from longitudinal normal and Poisson data. Two applications, of myopia twin and of corticospinal diffusion tensor tractography studies, are used for illustration. In conclusion, the VC approach with consideration of the correlation structure of longitudinal repeated measurements gives satisfactory results with small mean square errors and nominal 95% coverage rates for all sample sizes. [ABSTRACT FROM AUTHOR]

Published
2018
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3. Reproducibility of corticospinal diffusion tensor tractography in normal subjects and hemiparetic stroke patients.

Author

Lin, Chao-Chun, Tsai, Miao-Yu, Lo, Yu-Chien, Liu, Yi-Jui, Tsai, Po-Pang, Wu, Chiao-Ying, Lin, Chia-Wei, Shen, Wu-Chung, and Chung, Hsiao-Wen

Subjects
*PYRAMIDAL tract, *HEMIPARESIS, *STROKE treatment, *DIFFUSION tensor imaging, *MAGNETIC resonance imaging
Abstract

Abstract: Purpose: The reproducibility of corticospinal diffusion tensor tractography (DTT) for a guideline is important before longitudinal monitoring of the therapy effects in stroke patients. This study aimed to establish the reproducibility of corticospinal DTT indices in healthy subjects and chronic hemiparetic stroke patients. Materials and methods: Written informed consents were obtained from 10 healthy subjects (mean age 25.8±6.8 years), who underwent two scans in one session plus the third scan one week later, and from 15 patients (mean age 47.5±9.1 years, 6–60 months after the onset of stroke, NIHSS scores between 9 and 20) who were scanned thrice on separate days within one month. Diffusion-tensor imaging was performed at 3T with 25 diffusion directions. Corticospinal tracts were reconstructed using fiber assignment by continuous tracking without and with motion/eddy-current corrections. Intra- and inter-rater as well as intra- and inter-session variations of the DTT derived indices (fiber number, apparent diffusion coefficient (ADC), and fractional anisotropy (FA)) were assessed. Results: Intra-session and inter-session coefficients of variations (CVs) are small for FA (1.13–2.09%) and ADC (0.45–1.64%), but much larger for fiber number (8.05–22.4%). Inter-session CVs in the stroke side of patients (22.4%) are higher than those in the normal sides (18.0%) and in the normal subjects (14.7%). Motion/eddy-current correction improved inter-session reproducibility only for the fiber number of the infarcted corticospinal tract (CV reduced from 22.4% to 14.1%). Conclusion: The fiber number derived from corticospinal DTT shows substantially lower precision than ADC and FA, with infarcted tracts showing lower reproducibility than the healthy tissues. [ABSTRACT FROM AUTHOR]

Published
2013
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