• Journal of Digital Contents Society
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• v.14 no.2
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• pp.275-282
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• 2013

In medical image processing field, object recognition is usually carried out by computerized processing of various input information such as brightness, shape, and pattern. If the information mentioned does not make sense, however, many limitations could occur with object recognition during computer processing. Therefore, this paper suggests effective object recognition method based on the magnetic resonance (MR) theory to resolve the basic limitations in computer processing. We propose the efficient method of robust gray-white matter segmentation by texture analysis through the Susceptibility Weighted Imaging (SWI) for contrast enhancement. As a result, an average area difference of 5.2%, which was higher than the accuracy of conventional region segmentation algorithm, was obtained.

• Investigative Magnetic Resonance Imaging
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• v.11 no.2
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• pp.87-94
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• 2007

Purpose: The purpose of this study was to evaluate the usefulness of fast inversion recovery (FIR) and magnetization-prepared three dimensional gradient echo sequence (3D GRE) T1-weighted sequences for neonatal brain imaging compared with spin echo (SE) sequence in a 3T MR unit. Materials and Methods: T1-weighted axial SE, FIR and 3D GRE sequences were evaluated from 3T brain MR imaging in 20 neonates. The signal-to-noise ratio (SNR) of different tissues was measured and contrast-to-noise ratios (CNR) were determined and compared in each of the sequences. Visual analysis was carried out by grading gray-white matter differentiation, myelination, and artifacts. The Wilcoxon signed ranked test was used for evaluation of the statistical significance of CNR differences between the sequences. Results: Among the three sequences, the 3D GRE had the best SNRs. CNRs obtained with FIR and 3D GRE were statistically superior to those obtained with SE; these CNRs were better on the 3D GRE compared to the FIR. Gray to white matter differentiation and myelination were better delineated on the FIR and 3D GRE than the SE. However, motion artifacts were more commonly observed on the 3D GRE and flow-related artifacts of vessels were frequently seen on the FIR. Conclusion: FIR and 3D GRE are valuable alternative T1-weighted sequences to conventional SE imaging of the neonatal brain at 3T providing superior image quality.

• Korean Journal of Cognitive Science
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• v.28 no.4
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• pp.267-297
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• 2017

The anatomical structure of the brain reflects a great amount of information about an individual's cognitive ability. The present study reviewed research on developmental changes in brain structure in relation to biological maturation and intellectual growth focusing on children and adolescents. The purpose of the present study was to achieve an understanding of how children and adolescents' brain matures with development and also to examine whether individual differences in intelligence influences the development of brain structure. The first section introduces methods of measurement and analysis of brain structure, such as voxel-based morphometry and structural covariance. The second section reviews studies on the biological maturation of the brain and variables that influence brain development such as sex, environmental factors, and mental disorders, etc. The third section introduces the Parieto-Frontal Integration Theory of intelligence and reviews studies on the association between intelligence and developmental changes of the brain, including changes in structural covariance and functional connectivity. We conclude with a discussion on educational/clinical implications of this work and directions for future studies.

• Journal of Biomedical Engineering Research
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• v.25 no.1
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• pp.43-47
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• 2004

Interests in human brain functionality and its connectivity have much frown up. DTI (Diffusion tensor imaging) has been known as a non-invasive MR) technique capable of providing information on water diffusion in tissues and the organization of white matter tract. Thus. It can provide us the information on the direction of brain fiber tract and the connectivity among many important cortical regions which can not be examined by other anatomical or functional MRI techniques. In this study. was used the 24 bit color coding scheme on the IDL platform in the windows environment to visualize the orientation of major fiber tracts of brain such as main association, projection, commissural fibers and corticospinal tracts. We additionally implemented a color coding scheme for each directional component and FA (fractional anisotropy), and used various color tables for them to be visualized more definitely. Consequently we implemented a fancy and basic technique to visualize the directional information of fiber tracts efficiently and we confirmed the feasibility of the 24 bit color coding scheme in DTI by visualizing main fiber tracts.

• Journal of the Korean Society of Radiology
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• v.84 no.1
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• pp.240-252
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• 2023

Purpose To assess the effect of deep learning image reconstruction (DLIR) for head CT in pediatric patients. Materials and Methods We collected 126 pediatric head CT images, which were reconstructed using filtered back projection, iterative reconstruction using adaptive statistical iterative reconstruction (ASiR)-V, and all three levels of DLIR (TrueFidelity; GE Healthcare). Each image set group was divided into four subgroups according to the patients' ages. Clinical and dose-related data were reviewed. Quantitative parameters, including the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), and qualitative parameters, including noise, gray matter-white matter (GM-WM) differentiation, sharpness, artifact, acceptability, and unfamiliar texture change were evaluated and compared. Results The SNR and CNR of each level in each age group increased among strength levels of DLIR. High-level DLIR showed a significantly improved SNR and CNR (p < 0.05). Sequential reduction of noise, improvement of GM-WM differentiation, and improvement of sharpness was noted among strength levels of DLIR. Those of high-level DLIR showed a similar value as that with ASiR-V. Artifact and acceptability did not show a significant difference among the adapted levels of DLIR. Conclusion Adaptation of high-level DLIR for the pediatric head CT can significantly reduce image noise. Modification is needed while processing artifacts.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.7
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• pp.487-494
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• 2013

Medical image watermarking has received extensive attention as wide security services in the healthcare information system. This paper proposes a blind medical image watermarking approach on the segmented gray-matter (GM) images by utilizing discrete wavelet transform (DWT) and discrete cosine transform (DCT) along with enhanced suppressed fuzzy C-means (EnSFCM) for the optimal selection of sub-blocks position to insert a watermark. Experimental results show that the proposed approach outperforms other methods in terms of peak signal to noise ratio (PSNR) and M-SVD. In addition, the proposed approach shows better robustness than other methods in normalized correlation (NC) values against several attacks, such as noise addition, filtering, JPEG compression, blurring, histogram equalization, and cropping.

• Journal of Korean Physical Therapy Science
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• v.7 no.2
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• pp.513-521
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• 2000

This study was carried out to investigate the effects of electrical stimulation on the change Tyrosine-Hydroxylase immunoreactive(TH-IR) cells in the Central gray and retrorubral field of the male SD rats. 9 healthy and normal rats were divided into three groups, 3 SD rat in each group. The one group has been stimulated by electroacupuncture(EA, 2Hz) for 30min and the other group by EA for 1hr 30min and control group has been stimulated. TH-IR cells were found in the Central gray(CG) and Retrorubral field(RF). The numbers of TH-IR cells of CG and RF were significantly increased after 30 min (CG $6.2{\pm}0.83$, RF $1.4{\pm}0.55$)as compared with control group(CG $24{\pm}3.16$, RF $6.4{\pm}0.55$) and were also significantly increased after 1hr 30min(CG $75.6{\pm}4.51$, RF $18.8{\pm}0.89$) than 30min. These results show that TH is related into CG and RF in response to electrical stimulation.

• The Korean Journal of Physiology
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• v.4 no.2
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• pp.83-89
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• 1970

전기적 자극법은 심맥관계기능의 신경성조절을 이해하기위해 널리 이용되는 방법이며, 일반적으로 중추신경에는 고빈도, 말초신경에서는 저빈도 자극에 의해 최대반응이 유발된다고 알려지고 있으며, 이는 흥분파의 민도가 말초로 내려오며 감소되기 때물이라 해석되고 있다. 또한편 신경계의 어떤 단위위에서건 자극민도가 어느 한계를 넘으면 유발된 반응은 유지되지를 못하고 감쇠소실되는 것으로 이는 주로 시납스간 흥분파전달능 부전에 기인될 것이라고 믿어지고있다. 그러나 고위주추계와 말초를 연결하고 있는 척수에 있어서는 아직 최적전기적 자극조건도 분명히 알려져 있지 않을 뿐 아니라 이 부위에서도 고빈도자극시에 반응이 어느 정도 감쇠하는지에 대한 보고가 없기에 이를 추구코자 저자는 고양이의 상부경수를 면수와 연결부에서 완전 절단하기 전후 여러가지 자극조건으로 자극하여 몇 가지 결론을 얻었기에 보고하는 바이다. 1) 연수와 연결부에서 완전절단을 하기 전에는 경수$(C_1{\sim}C_2)$의 백질, 회백질의 여러부위에서 심맥관반응이 유발되었으나 절단후에는 백질중의 만두부위(좌 $2{\sim}3\;mm$, 배면으로 부터 $0.3{\sim}1.0\;mm$및 $2.5{\sim}3.5\;mm$)에만 반응이 유발되었으며, 이 두 부위는 심맥관계기능을 지배조절하는 원심성 섬유의 통로라고 사료되었다. 2) 최대반응은 자극조건(빈도 자극파지속시간 강도) 100/sec-1 mesc-3V 및 20/sec-3 msec-3V에서. 최장지속반응은 20/sec-3msec에서 유발되었으므로, 후자가 척수부에 있어 심맥관계반응을 유발키 위한 최적자극조건으로 생각된다. 3) 자극면도 20/sec 이하에서 반응유지가 잘된다는 결과는 생리적 조건하에서 척수를 통과하는 흥분파의 빈도가 20/sec를 넘지 않을 것이란 것을 시사한다. 4) 반응지속정도는 최초의 최대반응의 반으로 감쇠되기까지 소요되는시간 즉 50% 반응감쇠시간으로 표시하였으며, 척수에서는 대뇌피질 및 간뇌에서보다 심맥관계반응의 50%반응감쇠시간이 현저히 긴 것을 알 수 있었다.

• Korean Journal of Biological Psychiatry
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• v.16 no.3
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• pp.190-197
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• 2009

Objectives : The purpose of this study was to examine structural abnormalities of brain in patients with pathological gambling(PG) using voxel-based morphometry. Methods : We compared gray matter(GM) volumes between 10 patients with PG and 14 age- and IQ-matched healthy controls and examined the relationship of GM volumes with clinical variables in patients with PG. Results : We found significant increase of GM volume in the superior, middle, and inferior frontal gyri, the midbrain, the middle temporal gyrus, the precuneus, and the fusiform gyrus of patients with PG. A significant decrease of GM volume was observed in the parahippocampal gyrus and the lingual gyrus of the patient group. In addition, GM volumes in some of these regions were positively associated with South Oaks Gambling Screen score and negatively with age of onset in patients with PG. Conclusion : Current findings indicate that structural abnormalities in the fronto-temporal cortex, the midbrain, and the precuneus might be involved in the pathophysiology of PG, and contribute to some of the behavioral changes observed in patients with PG.

• Korean Journal of Biological Psychiatry
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• v.15 no.2
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• pp.118-125
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• 2008

Objectives : The purpose of this study was to find brain regions in which gray matter volume was reduced and to show the capability of voxel-based morphpmetry(VBM) analysis for lateralizing clinically significant brain regions in dementia of Alzheimer's type patients compared to healthy group. Methods : MR T1-weighted images of the 20 dementia of Alzheimer's type patients were compared with those of the 20 normal controls. Images were transformed to standard MNI space. In order to observe gray matter volume change. Gray matter was smoothed with a Gaussian kernel. After these preprocessing, statistical analysis was performed using statistical parametric mapping software(SPM2). Results : Gray matter volume was significantly reduced in the bilateral parahippocampal gyri, Lt. anterior cingulate gyrus, Lt. posterior cingulate gyrus, bilateral superior temporal gyri Lt. middle temporal gyrus, Lt. superior, bilateral middle, Rt. anterior frontal gyri and Rt. precuneus in dementia of Alzheimer's type patient group. Conclusions : These VBM results confirm previous findings of temporal lobe and limbic lobe atrophic changes in dementia of Alzheimer's type, and suggest that these abnormalities may be confined to specific sites within that lobe, rather than showing a widespread distribution.