• Title/Summary/Keyword: MRI 모델

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The effect of semantic categorization of episodic memory on encoding of subordinate details: An fMRI study (일화 기억의 의미적 범주화가 세부 기억의 부호화에 미치는 영향에 대한 자기공명영상 분석 연구)

  • Yi, Darren Sehjung;Han, Sanghoon
    • Korean Journal of Cognitive Science
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    • v.28 no.4
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    • pp.193-221
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    • 2017
  • Grouping episodes into semantically related categories is necessary for better mnemonic structure. However, the effect of grouping on memory of subordinate details was not clearly understood. In an fMRI study, we tested whether attending superordinate during semantic association disrupts or enhances subordinate episodic details. In each cycle of the experiment, five cue words were presented sequentially with two related detail words placed underneath for each cue. Participants were asked whether they could imagine a category that includes the previously shown cue words in each cycle, and their confidence on retrieval was rated. Participants were asked to perform cued recall tests on presented detail words after the session. Behavioral data showed that reaction times for categorization tasks decreased and confidence levels increased in the third trial of each cycle, thus this trial was considered to be an important insight where a semantic category was believed to be successfully established. Critically, the accuracy of recalling detail words presented immediately prior to third trials was lower than those of followed trials, indicating that subordinate details were disrupted during categorization. General linear model analysis of the trial immediately prior to the completion of categorization, specifically the second trial, revealed significant activation in the temporal gyrus and inferior frontal gyrus, areas of semantic memory networks. Representative Similarity Analysis revealed that the activation patterns of the third trials were more consistent than those of the second trials in the temporal gyrus, inferior frontal gyrus, and hippocampus. Our research demonstrates that semantic grouping can cause memories of subordinate details to fade, suggesting that semantic retrieval during categorization affects the quality of related episodic memory.

Segmentation and Visualization of Human Anatomy using Medical Imagery (의료영상을 이용한 인체장기의 분할 및 시각화)

  • Lee, Joon-Ku;Kim, Yang-Mo;Kim, Do-Yeon
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.1
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    • pp.191-197
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    • 2013
  • Conventional CT and MRI scans produce cross-section slices of body that are viewed sequentially by radiologists who must imagine or extrapolate from these views what the 3 dimensional anatomy should be. By using sophisticated algorithm and high performance computing, these cross-sections may be rendered as direct 3D representations of human anatomy. The 2D medical image analysis forced to use time-consuming, subjective, error-prone manual techniques, such as slice tracing and region painting, for extracting regions of interest. To overcome the drawbacks of 2D medical image analysis, combining with medical image processing, 3D visualization is essential for extracting anatomical structures and making measurements. We used the gray-level thresholding, region growing, contour following, deformable model to segment human organ and used the feature vectors from texture analysis to detect harmful cancer. We used the perspective projection and marching cube algorithm to render the surface from volumetric MR and CT image data. The 3D visualization of human anatomy and segmented human organ provides valuable benefits for radiation treatment planning, surgical planning, surgery simulation, image guided surgery and interventional imaging applications.

Performance of CMIP5 Models for the Relationship between Variabilities of the North Pacific Storm Track and East Asian Winter Monsoon (북태평양 스톰트랙 활동과 동아시아 겨울 몬순의 상관성에 관한 CMIP5 모델의 모의 성능)

  • Yoon, Jae-Seung;Chung, Il-Ung;Shin, Sang-Hye
    • Atmosphere
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    • v.25 no.2
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    • pp.295-308
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    • 2015
  • Based on the CMIP5 historical simulation datasets, we assessed the performance of state-of-the-art climate models in respect to the relationship between interannual variabilities of the North Pacific synoptic eddy (NPSE) and East Asian winter monsoon (EAWM). Observation (ERA-Interim) shows a high negative correlation (-0.73) between the interannual variabilities of East Asian winter monsoon (EAWM) intensity and North Pacific synoptic eddy (NPSE) activity during the period of 1979~2005. Namely, a stronger (weaker) EAWM is related to a weaker (stronger) synoptic eddy activities over the North Pacific. This strong reverse relationship can be well explained by latitudinal distributions of the surface temperature anomalies over East Asian continent, which leads the variation of local baroclinicity and significantly weakens the baroclinic wave activities over the northern latitudes of $40^{\circ}N$. This feature is supported by the distribution of the meridional heat flux (${\overline{{\nu}^{\prime}{\theta}^{\prime}}}$) anomalies, which have negative (positive) values along the latitudes $40{\sim}50^{\circ}N$ for strong(weak) EAWM years. In this study, the historical simulations by 11 CMIP5 climate models (BCC-CSM1.1, CanESM2, GFDL-ESM2G, GFDL-ESM2M, HadGEM2-AO, HadGEM2-CC, IPSL-CM5A-LR, MPI-ESM-LR, MPI-ESM-MR, MRI-CGCM3, and NorESM1-M) are analyzed for DJF of 1979~2005. Correlation coefficient between the two phenomena is -0.59, which is comparable to that of observation. Model-to-model variation in this relationship is relatively large as the range of correlation coefficient is between -0.76 (HadGEM2-CC and HadGEM2-AO) and -0.33 (MRI-CGCM3). But, these reverse relationships are shown in all models without any exception. We found that the multi-model ensemble is qualitatively similar to the observation in reasoning (that is, latitudinal distribution of surface temperature anomalies, variation of local baroclinicity and meridional heat flux by synoptic eddies) of the reverse relationship. However, the uncertainty for weak EAWM is much larger than strong EAWM. In conclusion, we suggest that CMIP5 models as an ensemble have a good performance in the simulation of EAWM, NPSE, and their relationship.

Development of a Discogenic Pain Animal Model: Preliminary Study (추간판성통증 동물모델의 개발: 초기 연구)

  • Kim, Byung-Jo;Lee, Min;Lim, Eun-Jeong;Yu, Sung-Wook;Hong, Sung-Ha;Hong, Seok-Joo;Na, Heung-Sik
    • Annals of Clinical Neurophysiology
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    • v.11 no.2
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    • pp.41-47
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    • 2009
  • Background: Discogenic pain can develop into chronic low back pain that is very difficult to treat effectively, because the pathogenesis of the disease still remains controversial. To clarify the pathogenesis, numerous animal models of intervertebral disc degeneration have been proposed in the literature, each with attendant advantages and disadvantages. The aim of this study was to determine the most efficacious method and dose of complete Freund's adjuvant (CFA) injection into intervertebral disc to develop a discogenic pain in a rat. Methods: CFA was injected into the L5-L6 or L4-L5 disc of male Sprague-Dawley rats in various conditions including a dose of CFA (10, 20, or 50 uL), drilling, injection site sealing using cyanoacrylate, and injection velocity. Sham animals were subjected to the same procedure, except for the CFA injection. Mechanical and heat allodynia were serially measured at both hindpaws until 8 weeks post-operatively. Serial MRI analyses were performed to observe degenerative changes of the discs. In addition, CGRP & Substance P-immunoreactivities (ir) in the superficial dorsal horn were evaluated at 4 weeks using immunohistochemistry. Results: Each condition provoked various problems such as development of hindpaw paralysis, CFA leakage, and no pain development. Mid-sagittal T2 MRI revealed no significant degenerative changes in the CFA injected disc. The CGRP-ir of the bilateral superficial dorsal horns at the level of L5-L6 was significantly increased in the CFA group. Conclusions: A total of 10 uL CFA injection into L5-L6 disc for a period of 10 minutes using a 26-gauge needle without drilling was the most efficacious way to develop discogenic pain animal model.

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A Case Study of Family Therapy for Marriage Migrant Woman who Experienced Family Violence - Focusing on Chinese Woman Who Participated in Counseling alone - (가정폭력 피해 결혼이주여성의 가족치료 사례연구: 단독으로 상담에 참여한 중국출신 여성을 중심으로)

  • Moon, Jung Hwa
    • Korean Journal of Family Social Work
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    • no.55
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    • pp.91-128
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    • 2017
  • The purpose of this study is to develop an effective intervention strategy for marriage migrant woman in family therapy. For this purpose, we collected counseling cases of professional counselors who successfully completed counseling and attempted the qualitative analysis of treatment intervention strategies and effects. The results of the study were obtained by dividing the meaning units in the immigrant woman's statements made during the counseling process composed of a total of 6 sessions. The counselors were analyzed to have tried the following intervention strategies. They attempted the following six strategies: Helping emotional differentiation by searching for unresolved emotional problems, dealing with undifferentiation due to family projection process and love triangle, dealing with multi-generational transfer process of the original family relationship patterns and coping mechanism, shedding lihgt on ineffectiveness of inconsistent communication due to emotional oppression applying a communication model of MRI, switching client's awareness through reorganization, suggesting a way of communication that leads to real self. Such counselors' attempts resulted in positive changes and treatment effects were found to include first, cognitive insights and motivation for change, second, improved communication skills and third, anxiety reduction and self-differentiation. Due to their husbands' refusal to participate in counseling, marriage migrant women often get involved in counseling alone, so they tend to worry that the effectiveness of family therapy may be low but it was found that the proper intervention of the counselor could improve the ability of the wife to resolve conflicts, which would be a great help in solving problems such as family violence and this study is meaningful in that it provided the appropriate therapeutic intervention strategies needed.

Quantitative Analysis of Fluid Velocity and Signal Loss of the TOF-MRA in a 3.0T MR System: Using the Flow Rate Control Phantom (3.0T MR system에서 TOF-MRA의 유체속도와 신호소실의 정량분석 : 유속조절팬텀 이용)

  • Back, Sang-Hoon;Jeong, Jin-Heon;Lee, Ye-Eun;Gwak, Min-Young;Yoon, Jun;Jung, Dabin;Oh, Hyun-Sik;Heo, Yeong-Cheol
    • Journal of the Korean Society of Radiology
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    • v.14 no.7
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    • pp.965-973
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    • 2020
  • The purpose of this study was to quantitatively correlate the change of flow velocity and signal voiding in TOF-MRA. We made our phantom to control the flow velocity, and changed the flow velocity in 16 steps from 8.0 to 127.3 mc/s. The TOF-MRA test was performed using a 3.0T MRI system and the signal intensity was measured by classifying the signal voiding length and image into the In flow, Mid flow, and Out flow. The length of signal voiding was the longest when the flow velocity was 127.3 cm/s and the signal intensity decreased with increasing flow velocity(p<0.05). In flow(-.547) and Mid flow(-.643) were negatively correlated with flow velocitys(p<0.05). In conclusion, it was confirmed that the increase in flow velocity was a major factor causing signal voiding in TOF-MRA. In the future, this study will provide basic data when studying sequences and parameters to reduce signal voiding in models with a high flow velocity.

Pattern Clustering of Symmetric Regional Cerebral Edema on Brain MRI in Patients with Hepatic Encephalopathy (간성뇌증 환자의 뇌 자기공명영상에서 대칭적인 지역 뇌부종 양상의 군집화)

  • Chun Geun Lim;Hui Joong Lee
    • Journal of the Korean Society of Radiology
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    • v.85 no.2
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    • pp.381-393
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    • 2024
  • Purpose Metabolic abnormalities in hepatic encephalopathy (HE) cause brain edema or demyelinating disease, resulting in symmetric regional cerebral edema (SRCE) on MRI. This study aimed to investigate the usefulness of the clustering analysis of SRCE in predicting the development of brain failure. Materials and Methods MR findings and clinical data of 98 consecutive patients with HE were retrospectively analyzed. The correlation between the 12 regions of SRCE was calculated using the phi (φ) coefficient, and the pattern was classified using hierarchical clustering using the φ2 distance measure and Ward's method. The classified patterns of SRCE were correlated with clinical parameters such as the model for end-stage liver disease (MELD) score and HE grade. Results Significant associations were found between 22 pairs of regions of interest, including the red nucleus and corpus callosum (φ = 0.81, p < 0.001), crus cerebri and red nucleus (φ = 0.72, p < 0.001), and red nucleus and dentate nucleus (φ = 0.66, p < 0.001). After hierarchical clustering, 24 cases were classified into Group I, 35 into Group II, and 39 into Group III. Group III had a higher MELD score (p = 0.04) and HE grade (p = 0.002) than Group I. Conclusion Our study demonstrates that the SRCE patterns can be useful in predicting hepatic preservation and the occurrence of cerebral failure in HE.

Development of Rabbit Brain Tumor Model Using VX2 Cells and Verification with the MRI in Neuroradiologic Research (Neuroradiology 연구를 위한 VX2 세포를 이용한 토끼 뇌종양 모델 제작과 MRI를 이용한 검증)

  • Yong-Woo Kim;Seon Hee Choi;Hak Jin Kim
    • Journal of the Korean Society of Radiology
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    • v.84 no.2
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    • pp.441-453
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    • 2023
  • Purpose To evaluate the development, location, and volume of a VX2 carcinoma using four inoculation methods in a rabbit brain. Materials and Methods Inoculation of a VX2 cell suspension was performed 1) on the appointed day, 2) seven days after storing a VX2 carcinoma in a freezer or 3) seven days after storing a VX2 carcinoma in a deep freezer after sacrificing the donor rabbits. 4) Without sacrificing the rabbits, the VX2 cell suspension was obtained using a gun biopsy, inoculation was performed on the appointed day. MR imaging was performed 10 days after inoculation. Brain tissues were obtained the day after. The development, location, and volume of the tumor were evaluated. Results Seventeen of the 18 rabbits inoculated on the appointed day developed tumors (average tumor volume, 106.32 mm3). One of five inoculated seven days after storing the VX2 tumor in the freezer, and three of five inoculated seven days after storing the VX2 tumor in the deep freezer developed tumors. Inoculation with a VX2 cell suspension obtained with a gun biopsy from five rabbits revealed development of tumors in only two rabbits. The tumors mostly developed in the superficial cortex. Conclusion TVX2 rabbit brain tumor model is easy to develop and revealed variable reproducibility. This model can be applicable in radiologic imaging, treatment planning, interventional treatment and drug delivery research. VX2 cell can be successfully innoculated into the brain using variable methods under researcher's variable conditions.

Automatic Prostate Segmentation in MR Images based on Active Shape Model Using Intensity Distribution and Gradient Information (MR 영상에서 밝기값 분포 및 기울기 정보를 이용한 활성형상모델 기반 전립선 자동 분할)

  • Jang, Yu-Jin;Hong, Helen
    • Journal of KIISE:Software and Applications
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    • v.37 no.2
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    • pp.110-119
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    • 2010
  • In this paper, we propose an automatic segmentation of the prostate using intensity distribution and gradient information in MR images. First, active shape model using adaptive intensity profile and multi-resolution technique is used to extract the prostate surface. Second, hole elimination using geometric information is performed to prevent the hole from occurring by converging the surface shape to the local optima. Third, the surface shape with large anatomical variation is corrected by using 2D gradient information. In this case, the corrected surface shape is often represented as rugged shape which is generated by the limited number of vertices. Thus, it is reconstructed by using surface modelling and smoothing. To evaluate our method, we performed the visual inspection, accuracy measures and processing time. For accuracy evaluation, the average distance difference and the overlapping volume ratio between automatic segmentation and manual segmentation by two radiologists are calculated. Experimental results show that the average distance difference was 0.3${\pm}$0.21mm and the overlapping volume ratio was 96.31${\pm}$2.71%. The total processing time of twenty patient data was 16 seconds on average.

Production and Usage of Korean Human Information in KISTI (KISTI에 있어서 한국인 인체정보의 생산과 활용)

  • Lee, Sang-Ho;Lee, Seung-Bock
    • The Journal of the Korea Contents Association
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    • v.10 no.5
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    • pp.416-421
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    • 2010
  • The KISTI (Korea Institute of Science and Technology Information) began to produce the Korean human information called Visible Korean and Digital Korean since 2000 because there was no human information in Korea which could represent the physical characteristics of Korean human body. The Visible Korean consists of CT, MR, sectioned and segmented images of Korean human body. We obtained the serially sectioned images by grinding the Korean cadaver in horizontal direction and segmented these images by outlining the inner organs of human. We have produced the sectioned images of Korean male whole body, male head, and female pelvis in2008. The segmentation and 3D reconstruction of these images are now in proceeding. The Digital Korean consists of CT images of about 100 Korean cadavers. These CT images were segmented by individual bone, reconstructed to produce the 3D bone models and the skin surface model was also added. The mechanical properties of individual bones were obtained by measuring the property of individual bone sample. We have distributed these Korean human informations to users in domestic and abroad. About 70 institutes in domestic, and 20 institutes in abroad have used our data in research use and nearly 160 proceedings and articles were published since 2001. We think these human informations have a role of medical information infrastructure that could be used in the field of medical education, biomechanics, virtual reality etc.