• Korean Journal of Oriental Medicine
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• v.6 no.1
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• pp.89-98
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• 2000

Cerebral ischemia, the most prevalent form of clinical stroke, is a medical problem of the first magnitude. Substantial efforts are being made to develop drugs which will protect the brain from the neurodegeneration followed by an ischemic stroke. A key factor in this process is the development of animal models that mimic the neuropathological consequences of stroke. Recently, there is increasing an evidence that free radical is involved in the mechanisms of ischemic brain damage. We investigated the macro scale gene expression analysis on the global ischemia induced by 4-vessel occlusion in Wister rats. The recent availability of microarrays provides an attractive strategy for elaborating an unbiased molecular profile of large number of genes during ischemic injury. This experimental approach offers the potential to identify molecules or cellular pathways not previously associated with ischemia. Ischemia was induced by 4-vessel occlusion for 10 minutes and reperfused again. RNA from sham control brain and time-dependent ischemed brain were hybridized to microarrays containing 4,000 rat genes. 589 genes were found to be at least 2 fold regulated at one or more time points. These survey data provide the foundation studies that should provide convincing proof for ischemia and oxidative stress on gene expression.

• Journal of Periodontal and Implant Science
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• v.35 no.2
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• pp.449-460
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• 2005

Objectives Aim of this study was to evaluate the clinical use and the efficacy of Frialit-2 implant system. Experimental Methods Fifty nine patients received placement of Frilalit-2 implants(137 implants) in their maxillary anterior and posterior sites(40 and 97 implants). Intraoral & clinical examination, chart review and radiographs were taken from each patient. Results 1. The total implant survival rate was 92.7% after a mean follow-up period of 19.9 months. 2. The implant survival rate placed in anterior region was 97.5%. 3. The implant survival rate placed in posterior region was 90.7%. 4. The implant survival rate placed in atrophic posterior maxilla with advanced technique (GBR, Sinus elevation) was 87.2%. 5. The implant survival rate placed in type N(D4) bone was 82%, while 95.7% in type III (D3), and 100% in type II(D2) bone. 6. Most of the failed implants(7 of 10) were removed during the maintenance stage after prosthodontic treatment. Conclusion It was concluded that Frialit-2 implant could be used satisfactorily in the esthetic anterior region, but the use in the posterior region, especially with poor bone quality and quantity, further studies are needed.

• Investigative Magnetic Resonance Imaging
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• v.26 no.1
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• pp.32-42
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• 2022

Purpose: To evaluate the clinical benefit of 2D contrast-enhanced T2 fluid-attenuated inversion recovery (CE-T2 FLAIR) image for detecting leptomeningeal metastasis (LM) in the brain metastasis work-up for lung cancer. Materials and Methods: From June 2017 to July 2019, we collected all consecutive patients with lung cancer who underwent brain magnetic resonance image (MRI), including contrast-enhanced 3D fast spin echo T1 black-blood image (CE-T1WI) and CE-T2 FLAIR; we recruited clinico-radiologically suspected LM cases. Two independent readers analyzed the images for LM in three sessions: CE-T1WI, CE-T2 FLAIR, and their combination. Results: We recruited 526 patients with suspected lung cancer who underwent brain MRI; of these, we excluded 77 (insufficient image protocol, unclear pathology, different contrast media, poor image quality). Of the 449 patients, 34 were clinico-radiologically suspected to have LM; among them, 23 were diagnosed with true LM. The calculated detection performance of CE-T1WI, CE-T2 FLAIR, and combined analysis obtained from the 34 suspected LM were highest in the combined analysis (AUC: 0.80, 0.82, and 0.89, respectively). The inter-observer agreement was also the highest in the combined analysis (0.68, 0.72, and 0.86, respectively). In quantitative analyses, CNR of CE-T2 FLAIR was significantly higher than that of CE-T1WI (Wilcoxon signed rank test, P < 0.05). Conclusion: Adding CE-T2 FLAIR might provide better detection for LM in the brain-metastasis screening for lung cancer.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.223-228
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• 2013

We evaluated the usefulness of $DTI_{6D}$ which was acquiring six direction diffusion data through compared to $DWI_{3D}$. Mean SNR and CNR were on $DWI_{3D}$ and $DTI_{6D}$ $44.01{\pm}13.36$, $37.15{\pm}11.44$ (p=0.029) and $18.47{\pm}9.66$, $19.88{\pm}9.20$(p=0.017). The number of lesions were $311{\pm}26.87$, $224.5{\pm}26.16$(p=0.041) on $DTI_{6D}$ and $DWI_{3D}$. Twenty patients were the more detected brain infarction lesion on $DTI_{6D}$. But there is no one the more detected on $DWI_{3D}$. And the more three direction diffusion data could get more information. However, we need to consider about the time consumption compared to DWI.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.05a
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• pp.496-498
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• 2023

Brain tumor segmentation problem has challenges in the tumor diversity of location, imbalance, and morphology. Attention mechanisms have recently been used widely to tackle medical segmentation problems efficiently by focusing on essential regions. In contrast, the fusion approaches enhance performance by merging mutual benefits from many models. In this study, we proposed a 3D dual fusion attention network to combine the advantages of fusion approaches and attention mechanisms by residual self-attention and local blocks. Compared to fusion approaches and related works, our proposed method has shown promising results on the BraTS 2018 dataset.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.3
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• pp.348-351
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• 2013

Recently, a brain imaging system with microwave devices has been proposed. The brain imaging system requires a small antenna which has ultra wide band(UWB) operating frequency bandwidth(0.5~2 GHz) and non-varying boresight of antenna over the frequency band. This paper proposes asymmetric corrugations on a tapered slot antenna (TSA) so that the size of the TSA is reduced by 14 % while 10 dB return loss bandwidth is satisfied over the operating frequency band from 0.5 GHz to 2 GHz. A miniaturized TSA with symmetric corrugations shows tilted boresight whilst frequency is getting lower; however, the proposed TSA with asymmetric corrugations maintains direction of boresight for different frequencies. This enhancements make an asymmetric corrugated TSA meet the requirement of the brain imaing system.

• Journal of Biomedical Engineering Research
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• v.25 no.1
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• pp.77-82
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• 2004

The purpose of this study is to establish a reference for image acquisition for completion of a standard brain for diverse Korean population, and to develop a management system that saves and manage database of the acquired brain image and personal information of those who were tested. 3D MP-RAGE technique, which has excellent SNR and CNR and reduces the times for image acquisition, was selected for anatomical Image acquisition, and parameter values were obtained for the optimal image acquisition. The database management system was devised to obtain not only anatomical image data but also subjects' basic demographic factors, medical history, handedness inventory state-trait anxiety inventory, A-type personality inventory, self-assessment depression inventory questionnaires of Sasang Constitution Mini-Mental State Examination, intelligence test, and personality test via a survey questionnaire and to save and manage the results of the tests. In addition, this system was designed to have functions of saving, inserting, deleting, searching, and Printing of image da a and personal information of subjects, and to have accessibility to them as well as automatic connection setup with ODBC. This newly developed system may have major contribution to the completion of a standard brain of diverse Korean population in that it can save and manage their image date and personal information.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.322-323
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• 2002

Partial volume averaging effect of PET data influences on the accuracy of quantitative measurements of regional brain metabolism because spatial resolution of PET is limited. The purpose of this study was to evaluate the accuracy of partial volume correction carried out on $^{18}$ F-PET images using Hoffman brain phantom. $^{18}$ F-PET Hoffman phantom images were co-registered to MR slices of the same phantom. All the MR slices of the phantom were then segmented to be binary images. Each of these binary images was convolved in 2 dimensions with the spatial resolution of the PET. The original PET images were then divided by the smoothed binary images in slice-by-slice, voxel-by-voxel basis resulting in larger PET image volume in size. This enlarged partial volume corrected PET image volume was multiplied by original binary image volume to exclude extracortical region. The evaluation of partial volume corrected PET image volume was performed by region of interests (ROI) analysis applying ROIs, which were drawn on cortical regions of the original MR image slices, to corrected and original PET image volume. From the ROI analysis, range of regional mean values increases of partial volume corrected PET images was 4 to 14%, and average increase for all the ROIs was about 10% in this phantom study. Hoffman brain phantom study was useful for the objective evaluation of the partial volume correction method. This MR-based correction method would be applicable to patients in the. quantitative analysis of FDG-PET studies.

• Journal of Aquaculture
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• v.19 no.3
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• pp.197-204
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• 2006

The pathogenicity and infection route of the Scuticociliate, Philasterdies dicentrarchi, were investigated with the 3 and 5 cm-group of juvenile flounders, Paralichthys olivaceus. The infection rates of 3 cm-group were 40% four days post infection (D.P.I.) and increased to be 90.1% 24 D.P.I., whereas those of 5 cm-group were 20% 8 D.P.I., 42% 16 D.P.I., and 81% 24 D.P.I. The results showed there were several infection routes to internal organs Olive flounder. The first route was started with the infection at the soft part of caudal fin and later reached at fin ray and muscle tissue; the second one was started from lips and mouth tissue of upper jaw and later the pathogen could be observed at either muscle tissue or eyeball and brain; the third one was begun at caudal fin and later the pathogen reached at brain tissu'e through spiral cord; the fourth one was started with the infections at abdominal cavity and anus. P. dicentrarchi infected to brain tissue was first observed 14 D.P.I in 3 cm-group and 20 D.P.I. in 5 cm-group of the juvenile flounder. This indicated that the brain infection of P. dicentrarchi might occur faster in small-sized flounder than large-sized one.

• Journal of Digital Contents Society
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• v.7 no.1
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• pp.15-23
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• 2006

The hamonious development of human brain has been an indigenous objective of each age. A variety of training programs related to the purpose have turned up at an educational market and a commercial market, as well. I'd like to indicate, however, that these training methods are somewhat prejudiced and have some elements, inherently, which are against the development of human brain for one's whole personality. Therefore, the most desirable brain training program is to induce it to respond to various stimuli, to educate for itself and to generate continuously, to create and strengthen an innumerous synapse among brain cells, so as to form a nero-network. In this study, I have used a brain training program with multimedia which have been produced for a specific purpose. With this method, by measuring directly the effectiveness of human brain development, I have analysed more objectively and more quantitatively.