• 대한의용생체공학회:의공학회지
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• 제26권2호
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• pp.73-86
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• 2005

We need to flatten the brain cortex to smooth surface, sphere, or 2D plane in order to view the buried sulci. The rendered 3D surface of the segmented white matter and gray matter does not have the topology of a sphere due to the partial volume effect and segmentation error. A surface without correct topology may lead to incorrect interpretation of local structural relationships and prevent cortical unfolding. Although some algorithms try to correct topology, they require heavy computation and fail to follow the deep and narrow sulci. This paper proposes a method that corrects topology of the rendered surface fast, accurately, and automatically. The proposed method removes fractions beside the main surface, fills cavities in the inside of the main surface, and removes handles in the surface. The proposed method to remove handles has three-step approach. Step 1 performs smoothing operation on the rendered surface. In Step 2, vertices of sphere are gradually deformed to the smoothed surfaces and finally to the boundary of the segmented white matter and gray matter. The Step 2 uses multi-resolutional approach to prevent the deep sulci from geometrical intersection. In Step 3, 3D binary image is constructed from the deformed sphere of Step 2 and 3D surface is regenerated from the 3D binary image to remove intersection that may happen. The experimental results show that the topology is corrected while principle sulci and gyri are preserved and the computation amount is acceptable.

• Journal of Ginseng Research
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• 제21권1호
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• pp.53-60
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• 1997

The changes in aldehyde dehydrogenase(ALDH, E.C. 1.2.1.3.) activity in neurons and astrocytes isolated from rat brains were investigated after administration of ethanol and Korean red ginseng(Panax ginseng C.A. Meyer) saponln. The cerebral ALDH activity with acetaldehyde and Propionaldehyde was higher in the white matter than in the gray matter. However, using indole-3-a-cetaldehyde and 3,4-dihydroxyphenylacetaldehyde as substrates, there was no significant difference in activity between two regions in cerebrum. In ethanol treated group, ALDH activity with all the substrates in the gray and white matter was lower than in normal group. In ethanol-saponin treated group, the enzyme activity in the white matter remarkably Increased. The ALDH activity in neurons isolated from cerebral cortex in ethanol-treated group was lower than in normal group. In ethanol-saponin treated group, neuronal ALDH activity with propionaldehyde was significantly recovered but not with Indole-3-acetaldehyde. In astrocytes, although the ALDH activity with propionaldehyde in the ethanol-treated group was not changed as compared with normal group, considerable increase in activity was found in ethanol-saponin treated group. These results suggest that Korean red ginseng saponin may protect the neuronal functions from the toxic effects of acetaldehyde derived from ethanol by stimulation of ALDH activity in astrocytes surrounding nerve cells.

• Journal of Trauma and Injury
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• 제19권2호
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• pp.105-112
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• 2006

Purpose: Many stresses produce reactive oxygen species and bring about mechanism of antioxidant reaction. Cytokine and a neurotransmitter through the cell membrane, as well as signal transduction through the cell membrane, are used for various pathological condition of the brain, such as neurodegenerative disease. There are several antioxidant enzymes in cells (superoxcide dismutase, glutathion peroxidasae, peroxiredoxin catalase, etc.) Methods: This study used single- or double-label immunohistochemical techniques to analyze mouse spinal neuron cells expressing Prx I and Prx III after acute mobilization stress. Results: Prx I was observed in dendritic cell of the gray matter of the spinal cord, and Prx III was observed in the cytoplasm of the GM of the spinal cord. Conclusion: The results of this study will help to explain differences of expression in the distributions of the peroxiredoxin enzymes of the spinal cord.

• 생물정신의학
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• 제21권1호
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• pp.1-13
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• 2014

Normal aging causes changes in the brain volume, connection, function and cognition. The brain changes with increases in age and difference of gender varies at all levels. Studies about normal brain aging using various brain magnetic resonance imaging (MRI) variables such as gray and white matter structural imaging, proton spectroscopy, apparent diffusion coefficient, diffusion tensor imaging and functional MRI are reviewed. Total volume of brain increases after birth but decreases after 9 years old. During adulthood, total volume of brain is relatively stable. After 35 years old, brain shrinks gradually. The changes of gray and white matters by aging show different features. N-acetylaspartate decreases or remains unchanged but choline, creatine and myo-inositol increase with aging. Apparent diffusion coefficient decreases till 20 years old and then becomes stable during adulthood and increase after 60 years old. Diffusion tensor properties in white matter tissue are variable during aging. Resting-state functional connectivity decreases after middle age. Structural and functional brain changes with normal aging are important for studying various psychiatric diseases such as dementia, schizophrenia and bipolar disorder. Our review may be helpful for studying longitudinal changes of these diseases and successful aging.

• 한국초지조사료학회지
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• 제16권3호
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• pp.219-224
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• 1996

Silage comkv, suwwn 19). sorghum $\times$ sudangrass(p. 988) and winter ryeNaton) were cultivated on imperfectly drained paddy field under two different draining methods, subsurface darinage by PVC pipes and open ditsched surface drainage. The crops were harvested at the stage of hard dough for corn and soft dough for wrghum and rye. The soil physical properties. soil colors. soil structure and soil wetness were improved in the subsurface drainage. Gravitational water table occured depth in 110 cm(dry season)~75cm(rain season). In soil profile description, yellowish brown with yellowish red mottles and well developed granular structure were found in the surface A horizon. The portion of solid phase in subsoils(B horizon) was reduced from 48.6%(undrained) to 43.7 %. A blocky structure with dark gray to gray were described in the open ditsched surface drainage. Severe wet depression of the crops was observed due to it's higher moisture contents, where the gravitational water occured depth in 25~37cm during the rainy season. The chemical properties of paddy soils were less affected by drainage methods. The concentration of available phosphate. organic matter and exchangeable K, Ca and Mg were decreased in the subsurface drained soils. The annual dry matter yields of com-rye cropping were 17.8 ton in the undrained, 21.6 ton in the open ditsch drainage and 35.9 ton/ha in the subsurface drainage.

• 한국의학물리학회지:의학물리
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• 제24권2호
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• pp.108-118
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• 2013

동맥스핀표지(Arterial Spin Labeling: ASL) 뇌 관류 자기공명영상법을 이용한 뇌 관류영상기술이 일반적으로 환자의 질병진단에 일반적으로 사용하기 어려운 이유는 영상을 얻을 때 여러 인자들을 최적화시켜야만 좋은 질의 영상을 얻을 수 있기 때문으로 생각된다. 따라서, 본 논문의 목적은 동맥스핀표지 자기공명영상의 뇌 관류영상을 최적화 하기 위하여 필요한 여러 인자들의 변화에 따른 동맥스핀표지 신호변화를 3.0 테슬라 자기공명영상에서 관찰하는 것이다. 특히, 동맥시 핀표지 자기공명영상 신호 변화가 이들 인자에서 뇌 세포(brain tissues)의 영역에 따라서 어떻게 변화하는가를 평가하였다. 정상 성인 남성 5명을(평균연령 36세; 29세~41세) 대상에서 STAR (Signal Targeting with Alternating Radiofrequency) 동맥스핀표지 방법을 이용하여 3T 자기공명영상에서 영상을 얻었다. 실험은 첫째 영상획득 영역과 라벨링 영역간의 간격 변화에 따른 신호 변화 평가 실험, 둘째 라벨링 후의 시간 변화에 따른 신호 변화 평가 실험, 셋째 라벨링 두께의 변화에 따른 신호 변화 평가 실험, 넷째 슬라이스 획득 순서에 따른 신호 변화 평가실험을 하였다. 획득한 영상의 분석은 회백질과 백질, 전두엽, 측두엽, 후두엽, 두정엽에서의 관류신호변화를 얻어 분석하였다. 본 연구결과는 아래와 같았다: 1) 영상획득 영역과 라벨링 영역간의 간격 변화에 따른 관류 신호 변화 연구결과 전체 절편의 평균 값을 보면 회백질에서 좌측과 우측 모두에서 라벨링 간격이 증가할수록 신호가 낮아지는 경향을 보이고 있다. 라벨링 간격의 변화에 두정엽이 가장 영향을 적게 받고 후두엽이 가장 많은 영향을 받았다. 2) 라벨링 후의 시간 변화에 따른 관류 신호 변화 연구결과 회백질은 라벨링 지연시간 400 ms까지 양쪽 모두 감소하다가 라벨링 지연시간이 1,000 ms까지 증가하였다. 3) 라벨링 두께의 변화에 따른 관류 신호 변화 연구 결과 라벨링 두께가 증가에 따라 회백질과 백질의 신호강도는 점차적으로 증가하다가 120 mm 두께 이후에는 감소하였다. 4) 절편 획득 순서에 따른 관류 신호 변화 연구 결과 절편 획득 순서에 따른 백질과 회백질의 관류신호강도 값은 회백질과 백질 모두 머리의 꼭대기부터 영상을 획득하는 descend에서 신호강도가 높았다. 본 연구에서는 각 실험 조건에 따라서 관류신호 강도가 크게 변화를 하는 것을 보여 주었고, 따라서 실제 환자를 대상으로 관류 영상을 얻고자 할 경우에는 실제 임상 적용 전에 최적화된 프로토콜을 만든 후에 사용을 해야 할 것으로 생각한다. 특히 백질의 뇌 관류영상을 얻는 것은 아직 문제가 있는 것으로 생각이 된다.

• 대한핵의학회지
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• 제25권1호
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• pp.6-16
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• 1991

Regional cerebral blood flow (rCBF) was evaluated in 12 children ranging in age from 2.7 to 10.0 yr using $^{99m}Tc-HMPAO$ SPECT. For quantitative analysis, 13 pairs of homologous regions of interest (ROIs) were created on three attenuation-corrected 18.8 mm thick transverse slices matching the cerebral cortical regions, deep gray matter, cerebellar hemisphere, and vascular territories, and the semiquantitative indices including "right to left ratio" [(mean count/voxel of homologous right ROI) / (mean count/voxel of homologous left ROI)] and "regional index"(RI) [(mean count/voxel of a ROI)/ (mean count/voxel of all ROIs of each hemisphere)] were calculated. Mean values of right to left ratios of homologous regions ranged from 0.984 to 1.028 in children under 5 yr (group 1) and from 0.982 to 1.012 in children between 5 and 10 yr (group 2), and the mean $value{\pm}2S.D.$ for each region did not exceed 11% and 12% in group 1 and group 2, respectively. There were no statistically significant differences between the RIs of the homologous right and left regions. Significant differences of RIs were found both between vascular regions (p<0.0005 for goup 1, and p=0.0001 for goup 2) and between regions of cerebral cortices (p<0.0005 for group 1, and p<0.005 for group 2) with a relatively high value in the occipital cortex and the lower values in the cerebellum and deep gray matter among the regions of cerebral cortices in both groups. There were no significant differences between the RIs of corresponding regions of group 1 and group 2, except a significantly higher value of right deep gray matter in group 2 than in group 1(p=0.0301). The RIs of the superior frontal cortex and deep gray matter showed to be positively correlated with age (superior frontal cortex; right: rs=0.5254, p=0.0814, left : rs=0.5919, p=0.0496/deep gray matter; right: rs=0.8246, p=0.0062, left: rs=0.6266, p=0.0377). The results suggest that the rCBF pattern of children approaches that of adults in an accipito-rostral direction. This time course of rCBF changes is in agreement with behavioral, neurophysiological, and anatomical alterations known to occur in the developing brain.

• Annals of Clinical Neurophysiology
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• 제13권1호
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• pp.48-50
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• 2011

Myotonic dystrophy type 1 (DM1) is an autosomal dominant multisystem disorder caused by the expansion of cytosine-thymine-guanine (CTG) repeats in the myotonic dystrophy protein kinase (DMPK) gene. Some literatures indicated that DM1 had incidental CNS lesions such as white matter lesions and diffuse gray matter atrophy. We report a patient with DM1 whose brain magnetic resonance image (MRI) showed multifocal hyperintense lesions and cystic lesion on both frontotemporoparietal lobes.

• Applied Microscopy
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• 제26권2호
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• pp.243-252
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• 1996

Sodium selenite를 피하주사하고 은 증폭시켜 흰쥐 척수에 있는 아연이 함유된 신경원의 포체와 bouton을 표지하였다. 표지된 신경원 세포체는 회백질의 V, VI, VII 및 X층에 분포하였다. 8시간 생존시킨 경우 아연 셀레늄 반응물이 역행수송되어 세포체에 침전되었다. 이것은 척수에 있는 아연이 함유된 신경원의 전부 혹은 일부가 개재신경원인 것으로 생각된다. 1시간 생존시킨 경우 아연 침전물로 표지된 축삭 bouton들이 회백질과 백질의 척수전삭 및 복측삭에 있는 돌기에 분포하였다. 특히 AMG로 염색된 큰 형태의 bouton 이 IX층에 나타났다. 미세구조적으로 아연 침전물은 생존시간에 따라서 아연이 함유된 신경원의 세포질 리소좀이나 bouton 내의 vesicle에 위치하였다.

• 대한방사선기술학회지:방사선기술과학
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• 제43권6호
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• pp.453-460
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• 2020

The price of the Brain phantom (Hoffman 3D brain phantom) used in nuclear medicine is quite expensive, it is difficult to be purchased by a medical institution or an educational institution. Therefore, the purpose of present research is to produce a low-price 3D brain phantom and evaluate its usefulness by using a 3D printer capable of producing 3D structures. The New 3D brain phantom consisted of 36 slices 0.7 mm thick and 58 slices 1.5 mm thick. A 0.7 mm thick slice was placed between 1. 5 mm thick slices to produce a composite slice. ROI was set at the gray matter and white matter scanned with CT to measure and compare the HU, in order to verify the similarity between PLA which was used as the material for the New 3D brain phantom and acrylic which was used as the material for Hoffman 3D brain phantom. As a result of measuring the volume of each Phantom, the error rate was 3.2% and there was no difference in the signal intensity in five areas. However, there was a significant difference in the average values of HU which was measured at the gray and white matter to verify the similarity between PLA and acrylic. By reproducing the previous Hoffman 3D brain phantom with a 100 times less cost, I hope this research could contribute to be used as the fundamental data in the areas of 3D printer, nuclear medicine and molecular imaging and to increasing the distribution rate of 3D brain phantom.