• 제목/요약/키워드: White Matter

검색결과 500건 처리시간 0.021초

정상자돈 뇌의 신경교세포 집단출현에 관한 연구 (Studies on Congenital Focal Gliosis in the Brains of Normal Piglets)

  • 곽수동;김순복;여상건
    • 대한수의학회지
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    • 제28권1호
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    • pp.125-135
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    • 1988
  • Attempts of these studies were made to investigate the nonspecific congenital focal accumulation of ectodermal glial cells in the brain of normal piglets. The brain samples were taken from 1-,10-,20-,35-,45- and 70-day-old piglets from a SPF-pig farm and three model pig farms. Occurrences of neuroglial cell foci (NCF) on the brain were observed with light microscope. Appearance degrees of the congenital NCF on 10 to 16 cross section slides per a piglets brain were tentatively designed on a scale from degree+ to ⧻by NCF number: +, less than 20 of NCF number; ⧺, 21-40 of NCF number: ⧻, more than 41 of NCF number. The results obtained were as follows: 1. NCF in the brain were observed mainly on the cerebrum. Regions of higher frequencies on the cerebrum were ordered as subependymal layers of the lateral ventricles, peripheral regions of lateral ventricles in the white matter and some neuron layers under the molecular layer of the gray matter. But NCF were not observed in the cerebellum, pons, medulla oblongata and spinal cords. 2. On the subependymal layers of the lateral ventricles, NCF were observed in 100% of 27 piglets, and appearance degree of ⧻ was observed in 10 piglets(37.0%), ⧺ in 10 piglets(37.0%) and + in 7 Piglets(26.0%) of 27 piglets, respectively. 3. On the white matter of the cerebrum, NCF were observed in 25 piglets(92.6%) of 27 piglets, and appearance degree of ⧻ was observed in 3 piglets(11.1%), ⧺ in 13 piglets(48.2%), + in 9 piglets(33.3%) and - in 2 piglets(7.4%) of 27 piglets, respectively. 4. On the gray matter of the cerebrum, NCF were observed in 21 piglets(77.8%) of 27 piglets, and appearance degree of ⧻ was not observed, appearance degree of ⧺ was observed in 6 piglets(22.2%), + in 15 Piglets(55.6%) and - in 6 piglets(22.2%) of 27 Piglets, respectively. 5. NCF tended to be converged appearance on some regions and tended to be decreased markedly from 35th day after birth, and the shapes of NCF were: global or oval forms crowded by analogous shaped and stained cells in the empty spaces of the brain substrate or on one side of the blood vessels.

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명암도 응집성 강화 및 분류를 통한 3차원 뇌 영상 구조적 분할 (Structural Segmentation for 3-D Brain Image by Intensity Coherence Enhancement and Classification)

  • 김민정;이정민;김명희
    • 정보처리학회논문지A
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    • 제13A권5호
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    • pp.465-472
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    • 2006
  • 최근 대용량 의료영상 데이터로부터 인체 기관 또는 질환 부위 추출을 위한 영상 분할 기법이 매우 다양하게 제안되고 있으나, 뇌와 같이 다중 구조를 가지면서 구조간 경계 구분이 어려운 영상의 구조적 분할에는 한계를 가진다. 이를 위해 주로 복셀을 유한 개의 군집으로 분류하는 군집화 (clustering) 기법이 이용되나 이는 개별 복셀 단위의 연산을 수행함으로 인해 잡음의 영향을 받는 제한점이 있다. 그러므로 잡음의 영상을 최소화하고 영상 경계를 강화시키는 향상기법을 적용함으로써 보다 견고한 구조적 분할을 수행할 수 있다. 본 연구에스는 뇌 자기공명영상에 대하여 백질(white matter), 회백질(gray matter), 뇌척수액(cerebrospinal fluid)의 내부 구조를 효율적으로 추출하기 위한 필터링 기반 군집화에 의한 구조적 분할 기법을 제안한다. 우선 구조간 경계를 강화하고 구조 내 잡음을 약화시키기 위해 응집성 향상 확산 필터링(coherence enhancing diffusiion filtering)을 적용한다. 또한 이 과정을 통해 강화된 영상에 퍼지 c-means 군집화 기법을 적용하여 각 복셀이 속하는 구조에 해당하는 군집의 인덱스를 할당함으로써 구조적 분할을 수행한다. 제안된 구조적 분할기법은 기존의 가우시안 또는 일반적인 비등방성 확산 필터링과 군집화 기법을 적용한 기법에 비해 전문가의 수동분할 결과와의 일치 비율에 의한 분할 정확도를 향상시킴을 보였다. 또한 경계 부분에 있어서의 세밀한 분할을 통해 재생산 가긍하고 사용자 수동후 처리를 최소화할 수 있는 결과를 제시함으로써 형태적 뇌 이상 진단을 위한 효율적인 보조 수단을 제공한다.

Silent Microbleeds and Old Hematomas in Spontaneous Cerebral Hemorrhages

  • Lim, Jae-Bum;Kim, Ealmaan
    • Journal of Korean Neurosurgical Society
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    • 제46권1호
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    • pp.38-44
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    • 2009
  • Objective : The authors studied the risk factors of silent cerebral microbleeds (MBs) and old hematomas (OHs) and their association with concurrent magnetic resonance (MR) imaging findings in the patients of intracerebral hemorrhages (ICHs). Methods : From April 2002 to June 2007, we retrospectively studied 234 patients of primary hemorrhagic stroke. All patients were evaluated with computed tomography (CT) and 3.0-tesla MR imaging studies within the first week of admission. MBs and OHs were assessed by using $T2^{\ast}$-weighted gradient-echo (GRE) MR imaging. The patients were divided into 2 groups, depending on whether or not they had two GRE lesions of chronic hemorrhages. A correlation between MBs and OHs lesions were also statistically tested. Lacunes and white matter and periventricular hyperintensities (WMHs, PVHs) were checked by T1- and T2-weighted spin-echo and fluid attenuated inversion recovery sequences. Variables on the clinical and laboratory data and MR imaging abnormalities were compared between both groups with or without MBs and OHs. Results : MBs were observed in 186 (79.5%) patients and a total of 46 OHs were detected in 45 (19.2%) patients. MBs (39.6%), OHs (80.4%), and ICHs (69.7%) were most commonly located in the ganglionic/thalamic region. Both MBs and OHs groups were more frequently related to chronic hypertension and advanced WMHs and PVHs. The prevalence and number of MBs were more closely associated with OHs groups than non-OH patients. Conclusion : This study clearly demonstrated the presence of MBs and OHs and their correlation with hypertension and cerebral white matter microangiopathy in the ICHs patients. Topographic correlation between the three lesions (MBs, OHs, and ICHs) was also noted in the deep thalamo-basal location.

매연포집필터 과열로 발생한 디젤승용차화재 원인의 분석 (Analysis of a Car Fire Case Caused by the Overheating of a Diesel Particulate Filter)

  • 이의평
    • 한국화재소방학회논문지
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    • 제31권1호
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    • pp.89-97
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    • 2017
  • 본 연구에서는 서비스센터에서 정비를 받고 출고한 날로부터 5일 후 터널 주행 중에 발생한 디젤승용차 화재 사례를 조사분석하였다. 조사분석한 결과, 배기구 내부에 흰색 이물질이 다량 부착되어 있었고, 배기관의 중간에 설치된 diesel particulate filter (DPF) 위쪽의 차열재가 용융 및 소실되어 있었고, DPF 위쪽의 차실 내부 금속재 바닥이 천공되어 금속재 바닥 위에 놓인 고무매트가 연소된 케이스이었다. 그리고 DPF 앞쪽의 배기관에는 과열흔적이 없고 DPF부터 배기구까지의 배기관에 과열흔적이 있는 특이점이 있었다. 이러한 특이점들은 DPF가 과열되고 DPF에서 발화된 경우에만 나타나므로 이 승용차화재는 DPF 내부 과열에 의해 발생한 것으로 분석할 수 있었다. 그리고 이 승용차화재조사를 통해 디젤승용차 화재원인조사 과정에서 배기구 내부에서 흰색 이물질이 확인되는 경우에는 DPF를 분리하여 DPF 내부의 손상을 조사하여 화재원인을 판정하여야 함을 알 수 있었다.

A Understanding of the Temporal Stem

  • Choi, Chan-Young;Han, Seong-Rok;Yee, Gi-Taek;Lee, Chae-Heuck
    • Journal of Korean Neurosurgical Society
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    • 제47권5호
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    • pp.365-369
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    • 2010
  • Objective : There has been inconsistency about definition of the temporal stem despite of several descriptions demonstrating its microanatomy using fiber dissection and/or diffusion tensor tractography. This study was designed to clarify three dimensional configurations of the temporal stem. Methods : The fronto-temporal regions of several formalin-fixed human cerebral hemispheres were dissected under an operating microscope using the fiber dissection technique. The consecutive coronal cuts of the dissected specimens were made to define the relationships of white matter tracts comprising the temporal stem and the subcortical gray matters (thalamus, caudate nucleus, amygdala) with inferior limiting (circular) sulcus of insula. Results : The inferior limiting sulcus of insula, limen insulae, medial sylvian groove, and caudate nucleus/amygdala were more appropriate anatomical structures than the roof/dorso-lateral wall of the temporal horn and lateral geniculate body which were used to describe previously for delineating the temporal stem. The particular space located inside the line connecting the inferior limiting sulcus of insula, limen insulae, medial sylvian groove/amygdala, and tail of caudate nucleus could be documented. This space included the extreme capsule, uncinate fasciculus, inferior occipito-frontal fasciculus, anterior commissure, ansa peduncularis, and inferior thalamic peduncle including optic radiations, whereas the stria terminalis, cingulum, fimbria, and inferior longitudinal fiber of the temporal lobe were not passing through this space. Also, this continued posteriorly along the caudate nucleus and limiting sulcus of the insula. Conclusion : The temporal stem is white matter fibers passing through a particular space of the temporal lobe located inside the line connecting the inferior limiting sulcus of insula, limen insulae, medial sylvian groove/amygdala, and tail of caudate nucleus. The three dimensional configurations of the temporal stem are expected to give the very useful anatomical and surgical insights in the temporal lobe.

Patterns of ischemic injury on brain images in neonatal group B Streptococcal meningitis

  • Choi, Seo Yeol;Kim, Jong-Wan;Ko, Ji Won;Lee, Young Seok;Chang, Young Pyo
    • Clinical and Experimental Pediatrics
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    • 제61권8호
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    • pp.245-252
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    • 2018
  • Purpose: This study investigated patterns of ischemic injury observed in brain images from patients with neonatal group B Streptococcal (GBS) meningitis. Methods: Clinical findings and brain images from eight term or near-term newborn infants with GBS meningitis were reviewed. Results: GBS meningitis was confirmed in all 8 infants via cerebrospinal fluid (CSF) analysis, and patients tested positive for GBS in both blood and CSF cultures. Six infants (75.0%) showed early onset manifestation of the disease (<7 days); the remaining 2 (25.0%) showed late onset manifestation. In 6 infants (75%), cranial ultrasonography showed focal or diffuse echogenicity, suggesting hypoxic-ischemic injury in the basal ganglia, cerebral hemispheres, and periventricular or subcortical white matter; these findings are compatible with meningitis. Findings from magnetic resonance imaging (MRI) were compatible with bacterial meningitis, showing prominent leptomeningeal enhancement, a widening echogenic interhemisphere, and ventricular wall thickening in all infants. Restrictive ischemic lesions observed through diffusion-weighted imaging were evident in all eight infants. Patterns of ischemic injury as detected through MRI were subdivided into 3 groups: 3 infants (37.5%) predominantly showed multiple punctuate lesions in the basal ganglia, 2 infants (25.0%) showed focal or diffuse cerebral infarcts, and 3 infants (37.5%) predominantly showed focal subcortical or periventricular white matter lesions. Four infants (50%) showed significant developmental delay or cerebral palsy. Conclusion: Certain patterns of ischemic injury are commonly recognized in brain images from patients with neonatal GBS meningitis, and this ischemic complication may modify disease processes and contribute to poor neurologic outcomes.

소아에서 가역성 후두부 백질 뇌증 증후군의 임상적, 방사선학적 특성에 대한 고찰 (Clinical and Radiological Analysis of Reversible Posterior Leukoencephalopathy Syndrome in Children)

  • 임해리;서혜은;권순학
    • Clinical and Experimental Pediatrics
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    • 제50권9호
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    • pp.901-904
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    • 2007
  • 목 적 : 가역성 후두부 백질 뇌증 증후군은 두정-후두엽의 백질 혹은 회질을 침범하는 특징을 가지는 복합 증후군이다. 이번 연구에서는 이 증후군의 임상적, 방사선학적 특징을 분석하였다. 방 법 : 총 15명의 환아를 대상으로 하였으며. 각 환아에서 급성기 동안의 평균 동맥압을 측정하고 신경학적 사건이 발생하기 수일에서 수주 전 안정 상태의 평균 동맥압을 조사하여 비교하였다. 그리고 이들의 뇌자기 공명 영상을 분석 비교하였으며 모든 연구는 후향적으로 이루어졌다. 결 과 : 15명의 환아(남아 : 9명, 여아 : 6명)의 연령은 2-20세(평균 연령:10세)였다. 뇌 자기공명 영상은 두정-후두엽의 백질 및 피질에 T2-weighted image에서 신호 강도의 증가를 보였다. 대개의 경우에서 스테로이드나 싸이클로스포린 복용 혹은 급격하게 혈압이 증가하는 사건과 관련성을 보였다. 결 론 : 가역성 후두부 백질 뇌증 증후군은 복합적인 신경학적 질환으로 이 복합 증후군에 대한 더 많은 연구를 함으로써 불필요한 검사를 줄이고 즉각적이고 합당한 치료를 환아에게 행할 수 있을 것으로 생각한다.

Mild encephalopathy with a reversible splenial lesion in a girl with acute pyelonephritis

  • Yeom, Jung Sook;Koo, Chung Mo;Park, Ji Sook;Seo, Ji-Hyun;Park, Eun Sil;Lim, Jae-Young;Woo, Hyang-Ok;Youn, Hee-Shang
    • Clinical and Experimental Pediatrics
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    • 제61권2호
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    • pp.64-67
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    • 2018
  • We report the case of a 12-year-old girl who had mild encephalopathy with a reversible splenial lesion (MERS) associated with acutepyelonephritis caused by Escherichia coli. The patient was admitted with a high fever, and she was diagnosed with acute pyelonephritis based on pyuria and the results of urine culture, which detected cefotaxime-sensitive E. coli. Although intravenous cefotaxime and tobramycin were administered, her fever persisted and her C-reactive protein level increased to 307 mg/L. On day 3 of admission, she demonstrated abnormal neuropsychiatric symptoms, such as delirium, ataxia, and word salad. Magnetic resonance imaging (MRI) of the brain performed on day 4 showed marked hyperintensities in the bilateral corpus callosum and deep white matter on diffusion-weighted images, with corresponding diffusion restriction on apparent diffusion coefficient mapping. No abnormalities or pathogens were detected in the cerebrospinal fluid; however, lipopolysaccharides (LPS, endotoxin) were detected in plasma (41.6 pg/mL), associated with acute neurological deterioration. Her clinical condition gradually improved, and no neurological abnormalities were observed on day 6. Follow-up brain MRI performed 2 weeks later showed near-disappearance of the previously noted hyperintense lesions. In this patient, we first proved endotoxemia in a setting of MERS. The release of LPS following antibiotic administration might be related to the development of MERS in this patient. The possibility of MERS should be considered in patients who present with acute pyelonephritis and demonstrate delirious behavior.

Clinical Uses of Diffusion Tensor Imaging Fiber Tracking Merged Neuronavigation with Lesions Adjacent to Corticospinal Tract : A Retrospective Cohort Study

  • Yu, Qi;Lin, Kun;Liu, Yunhui;Li, Xinxing
    • Journal of Korean Neurosurgical Society
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    • 제63권2호
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    • pp.248-260
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    • 2020
  • Objective : To investigate the efficiency of diffusion tensor imaging (DTI) fiber-tracking based neuronavigation and assess its usefulness in the preoperative surgical planning, prognostic prediction, intraoperative course and outcome improvement. Methods : Seventeen patients with cerebral masses adjacent to corticospinal tract (CST) were given standard magnetic resonance imaging and DTI examination. By incorporation of DTI data, the relation between tumor and adjacent white matter tracts was reconstructed and assessed in the neuronavigation system. Distance from tumor border to CST was measured. Results : The sub-portion of CST in closest proximity to tumor was found displaced in all patients. The chief disruptive changes were classified as follows : complete interruption, partial interruption, or simple displacement. Partial interruption was evident in seven patients (41.2%) whose lesions were close to cortex. In the other 10 patients (58.8%), delineated CSTs were intact but distorted. No complete CST interruption was identified. Overall, the mean distance from resection border to CST was 6.12 mm (range, 0-21), as opposed to 8.18 mm (range, 2-21) with simple displacement and 2.33 mm (range, 0-5) with partial interruption. The clinical outcomes were analyzed in groups stratified by intervening distances (close, <5 mm; moderated, 5-10 mm; far, >10 mm). For the primary brain tumor patients, the proportion of completely resected tumors increased progressively from close to far grouping (42.9%, 50%, and 100%, respectively). Five patients out of seven (71.4%) experienced new neurologic deficits postoperatively in the close group. At meantime, motor deterioration was found in six cases in the close group. All patients in the far and moderate groups received excellent (modified Rankin Scale [mRS] score, 0-1) or good (mRS score, 2-3) rankings, but only 57.1% of patients in the close group earned good outcome scores. Conclusion : DTI fiber tracking based neuronavigation has merit in assessing the relation between lesions and adjacent white matter tracts, allowing prediction of patient outcomes based on lesion-CST distance. It has also proven beneficial in formulating surgical strategies.

조사료원에 따른 꽃사슴(Servus nippon)의 채식습성에 관한 연구 (A study on the food habits of Sika Deer (Saanen) fed with roughage sources)

  • 강병호;이인덕;이수기;이형석
    • 농업과학연구
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    • 제38권3호
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    • pp.437-444
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    • 2011
  • The object of this experiment was to investigate the food habits of sika deer fed with various roughage sources. The experimental trials were conducted at Unbong Animal Genetic Resources Station in 2008. The experimental roughages include five sources and 25 species in all; grasses and legumes: 5 species (mixed grasses, orchardgrass, tall fescue, alfalfa, white clover), native grasses and weeds: 5 species (mixed native grasses, Miscanthus sinensis Anderss, Arundinella hirta (Thunb.) Tanaka, barnyard grass, short awn, forage crops (hay, silages and straw): 5 species (barley + hairy vetch, Wheat + hairy vetch, rye silage, barley silage, baled rice straw), browse and fallen leaves: 5 species (mixed browse, oriental white oak, Quercus serrta Thunb., oriental cherry fallen leaves, Japanese chestnut fallen leaves), and imported hays and straws: 5 species (timothy hay, tall fescue straw, annual ryegrass straw, klinegrass hay, alfalfa hay). Five sika deer were used as experimental animals and the averaged body weight was 95+5.4kg. The chemical composition and dry matter digestibility of each roughage source and species were significantly different at the sampling area, plant species, growth stages and cutting period(p<0.05). The sika deer ate more roughages which had low fibrous contents, but high dry matter digestibility. Among all the 25 species of roughages, the favorite intake roughage sources ranking by sika deer was observed like this: browse and fallen leaves (32.2%), grass and legumes (27.0%), native grasses and weeds (22.0%), imported hays (12.9%) and forages crops (5.5%) respectively. Although, the sika deer ate more browse leaves, but ate more roughage which had low fibrous contents (NDF and ADF), but high drymatter digestibility. On the other hand, compared to each roughage source, total intake amount by sika deer was showed as browse and fallen leaves (32.2%). Based on the result, the food habit of sika deer seems to be closer to the typical browser.