• Proceedings of the KSMRM Conference
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• 1999.04a
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• pp.1-9
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• 1999

핵자기 공명(NMR:nuclear magnetic resonance)은 19451건 Bloch, Procell등에 의해 처음으로 실험적으로 입증된 후에 생화학 및 약학 분야에서 분자단위의 물질의 성분, 구조, 대사물질의 역학적 운동 및 상태에 관한 정보를 아는데 유용한 기법으로 사용 되어 왔다. 의학분야에서는 Lauterber등에 의해 자기공명영상볍(Magnetic Resonance Imaging:MRI)으로 개발되어 질병의 진단 및 치료에 많은 공헌을 하게되었다. 해부학적영상 뿐 아니라 분석방법으로 병변 부위 및 인체 기관에서의 각종 대사물질의 정량적인 양과 변화를 알 수 있는 자기공명분광기법(magnetic resonance spectroscopy:MRS)도 활발한 임상적용이 이루어지고 있다. 자기공명영상법의 활발한 임상적 응용 및 새로운 technique이해를 위해서는 물리학적 개념(MR Physics)을 이해하는 것이 매우 중요하다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.298-298
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• 2004

본 연구는 외부에서 고 농도 (30％)의 산소 공급이 공간 인지 능력에 어떠한 변화를 유발하는지 뇌기능 영상의 시계열 신호 분석을 통해 관찰하고자 한다. 8명의 오른손잡이 남자 대학생 (평균 23.5세)이 피험자로 참여하였다. 21％와 30％ 산소 농도를 각각 BL/min의 양으로 일정하게 공급할 수 있는 장치를 개발하였다. 공간 인지 능력 측정을 위해 20 문항을 포함하는 두 개의 문제지를 제작하였고, 과제 수행 결과로부터 정답률을 산출하였다. 3T MRI 기기를 사용하였고, single-shot EPI 방법으로 뇌기능 영상을 획득하였다.(중략)

• Proceedings of the Korean Information Science Society Conference
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• 2003.10b
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• pp.715-717
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• 2003

2차원 의료 영상으로부터 3차원 모델을 재구성 하면 여러 의학 분야에 효과적으로 활용할 수 있다. 컬러 영상이나 MRI의 영상은 표면을 자동으로 식별하기 어렵기 때문에 구역화한 결과로 나오는 외곽선으로부터 표면을 재구성해야한다. 표면 재구성을 위한 기존의 삼각형화 알고리즘은 모델이 복잡할 경우 수행속도가 저하되는 단점이 있다. 본 논문에서는 정합되는 부분과 나머지 부분을 따로 처리하는 기존 방법 대신에, 알맞은 위치에 연결간선들만 결정하여 연결한 후, 그 사이의 정점들을 연결하는 간단한 삼각형화 알고리즘으로 속도를 향상시키는 방법을 제안한다.

• Investigative Magnetic Resonance Imaging
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• v.8 no.2
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• pp.100-108
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• 2004

Purpose : Early degeneration of articular cartilage is accompanied by a loss of glycosaminoglycan (GAG) and the consequent change of the integrity. The purpose of this study was to biochemically quantify the loss of GAG, and to evaluate the $Gd(DTPA)^{2-}$-enhanced, and T1, T2, rho relaxation map for detection of the early degeneration of cartilage. Materials and Methods : A cartilage-bone block in size of $8mm\;\times\;10mm$ was acquired from the patella in each of three pigs. Quantitative analysis of GAG of cartilage was performed at spectrophotometry by use of dimethylmethylene blue. Each of cartilage blocks was cultured in one of three different media: two different culture media (0.2 mg/ml trypsin solution, 1mM Gd $(DTPA)^{2-}$ mixed trypsin solution) and the control media (phosphate buffered saline (PBS)). The cartilage blocks were cultured for 5 hrs, during which MR images of the blocks were obtained at one hour interval (0 hr, 1 hr, 2 hr, 3 hr, 4 hr, 5 hr). And then, additional culture was done for 24 hrs and 48 hrs. Both T1-weighted image (TR/TE, 450/22 ms), and mixed-echo sequence (TR/TE, 760/21-168ms; 8 echoes) were obtained at all times using field of view 50 mm, slice thickness 2 mm, and matrix $256\times512$. The MRI data were analyzed with pixel-by-pixel comparisons. The cultured cartilage-bone blocks were microscopically observed using hematoxylin & eosin, toluidine blue, alcian blue, and trichrome stains. Results : At quantitation analysis, GAG concentration in the culture solutions was proportional to the culture durations. The T1-signal of the cartilage-bone block cultured in the $Gd(DTPA)^{2-}$ mixed solution was significantly higher ($42\%$ in average, p<0.05) than that of the cartilage-bone block cultured in the trypsin solution alone. The T1, T2, rho relaxation times of cultured tissue were not significantly correlated with culture duration (p>0.05). However the focal increase in T1 relaxation time at superficial and transitional layers of cartilage was seen in $Gd(DTPA)^{2-}$ mixed culture. Toluidine blue and alcian blue stains revealed multiple defects in whole thickness of the cartilage cultured in trypsin media. Conclusion : The quantitative analysis showed gradual loss of GAG proportional to the culture duration. Microimagings of cartilage with $Gd(DTPA)^{2-}$-enhancement, relaxation maps were available by pixel size of $97.9\times195\;{\mu}m$. Loss of GAG over time better demonstrated with $Gd(DTPA)^{2-}$-enhanced images than with T1, T2, rho relaxation maps. Therefore $Gd(DTPA)^{2-}$-enhanced T1-weighted image is superior for detection of early degeneration of cartilage.

• Journal of Korea Multimedia Society
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• v.19 no.2
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• pp.375-385
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• 2016

Recently, several implantable hearing aids such as cochlear implant, middle ear implant, etc., which have a module receiving power and signal from outside the body, are frequently used to treat the hearing impaired patients. Most of implantable hearing aids are adopted permanent magnet pairs to couple between internal and external devices for the enhancement of power transmission. Generally, the internal device which containing the magnet in the center of receiving coil is implanted under the skin of human temporal bone. In case of MRI scanning of a patient with the implantable hearing aid, however, homogeneous magnetic fields of the MRI might be interfered by the implanted magnet. For the above reasons, the MR image is degraded by large area of artifact, so that diagnostics are almost impossible in deteriorated region. In this paper, we proposed an external coil system that can reduce the artifact of MR image due to the internal coupling magnet. By finite element analysis estimating area of MR artifact according to varying current and shape of the external coil, optimal coil parameters were extracted. Finally, the effectiveness of the proposed external coil system was verified by confirming the artifact at real MRI scan.

• Proceedings of the Korean Information Science Society Conference
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• 2010.11a
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• pp.27-31
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• 2010

본 논문에서는 하이퍼그래프의 고유벡터를 척도로 하여 fMRI기반 Brain Network를 분석하여 중요한 허브노드를 찾는 방법론을 제시한다. 이 방법을 비디오게임을 수행하면서 촬영한 기능적 자기뇌영상(fMRI) 데이터인 PBAIC 2007 데이터셋에 대하여 그 유용성을 검증하였다. 이 데이터는 각 20분씩 세 세션을 촬영한 것이며 처음 두 세션에는 13가지의 감정 항목의 평가치가 각 스캔마다 주어진다. 한 피험자의 첫번째 세션 데이터로부터 13가지 감정 항목에 대하여 상관관계가 높은 각각의 복셀(voxel)들을 추출하였다. 이 13가지의 복셀들의 집합들을 각각 하이퍼에지로 보고 하이퍼그래프를 구성하였다. 하이퍼그래프로부 터 인접 행렬(adjacency matrix)를 구성한 후 고유치(eigenvalue)와 고유벡터(eigenvector)를 구하였다. 여기서 고유치가 가장 큰 고유벡터의 원소들은 각 복셀들의 중앙성(centrality), 즉 중요성을 나타내며 이로부터 감정과 관련된 중요한 허브 복셀들과 그들의 국소적 집합인 모듈을 찾았다. 모듈들은 감정 및 작업기억(working memory)과 관련된 뇌 영역들의 클러스터(cluster)로 추정된다.

• Korean Journal of Psychosomatic Medicine
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• v.9 no.1
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• pp.37-48
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• 2001

Objectives : The purpose of this study was to evaluate the difference of psychometric analysis among patients with Post-traumatic organic mental disorder according to the lesion of MRI finding of traumatic brain injury. Methods : We divided 35 patients into 4 groups according to the lesion of MRI finding of brain injury. We evaluated the difference of the subscales of MMPI and K-WAIS among 4 groups with Post-traumatic organic mental disorder by ANOVA. Results : We found no significant difference of all subscales of MMPI and K -WAIS among 4 groups by ANOVA. Compared Rt hemispheric injury group with Lt hemispheric injury group by independent t-test, the depression scale in MMPI scored significantly higher in Lt hemispheric injury group, and the block design in K-WAIS scored significantly lower in Rt hemispheric injury group. Conclusion : This study suggests that Lt hemispheric injury be significantly related to depression, and Rt hemispheric injury be significantly related to visuospatial ability.

• Journal of Acupuncture Research
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• v.24 no.5
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• pp.229-240
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• 2007

Objectives : The purpose of this study is to report the image changes of five cases of Cervical intervertebral disc Herniation after Oriental medicine Treatment. Patient & Methods : We examined 5 patients with Cervical intervertebral disc Herniation (HIVD of C-spine) who showed changes on MRI images before/after the treatment among HIVD of C-spine patients who visited Cervical Spine center, Jaseng Hospital of Oriental Medicine from March, 2006 to May, 2007. Results & Conclusions : In this study, the first MRI examination of HIVD of C-spine patients was performed at the first visit and re-examination of MRI was done after the treatment. We assessed clinical symptoms by using Numerical rating scales(NRS). In each case, the size of the disc herniation was considerably reduced in MRI image. NRS was also reduced significantly.

• Imaging Science in Dentistry
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• v.47 no.4
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• pp.219-226
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• 2017

Purpose: This study investigated the relationship between pain and internal derangement in temporomandibular disorder(TMD) patients using magnetic resonance imaging (MRI). Materials and Methods: This study analyzed 356 TMD patients (712 temporomandibular joints [TMJs]). The inclusion criteria were the presence of spontaneous or provoked pain on one or both TMJs and having undergone MRI. The patients with provoked pain were divided into 3 groups: pain on palpation, pain on mouth opening, and pain on mastication. MRI was performed using a 1.5-T scanner. T1- and T2-weighted parasagittal and paracoronal images were obtained. According to the findings on the T1-weighted images, another 3 groups were created based on internal derangement: normal, disc displacement with reduction, and disc displacement without reduction. The MRI findings were independently interpreted by 2 experienced oral and maxillofacial radiologists at 2 different times. Statistical analysis was performed by the chi-square test using SPSS (version 12.0; SPSS Inc., Chicago, IL, USA). Results: Provoked pain on mouth opening was found to be correlated with internal derangement in TMD patients (P<.05). However, spontaneous pain and provoked pain on palpation or mastication were not associated with internal derangement(P>.05). Conclusion: These results suggest that internal derangement was a significant predictor of provoked pain on mouth opening.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.4 no.2
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• pp.185-196
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• 2009

Objective: The purpose of this study is to investigate the effects of oriental medicine conservative treatment on patients who show symptoms at the legion opposed to that shown in Magnetic Resonance Image(MRI) findings. Subject & Method: Oriental medicine treatment such as acupuncture and herbs was applied to two patients who were diagnosed as lateral herniated intervertebral disc of lumbar spine via MRI but whose pain and muscular force attenuation were shown at the opposed lower limb, for measuring its effects. Results: As for the two cases, the patients were favored in the Visual Analog Score (VAS) and the Straight leg Raising(SLR) test after the oriental medicine conservative treatment. In one case, the muscular force in the lower limb was favored. Conclusion: Based on the results in this study, oriental medicine conservative treatment might be effective on patients who show symptoms at the legion opposed to that shown in MRI findings.