• 한국콘텐츠학회논문지
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• 제3권3호
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• pp.85-97
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• 2003

MRI, CT, MRI, PET, SPECT, fMRI 등과 같은 단층의료영상은 병원에서 환자의 진단 및 치료 임상적 연구에서 폭넓게 사용되고 있다. 동일한 대상에 대하여 서로 다른 정보를 얻거나 비교를 하기 위하여 서로 다른 영상양식으로 촬영하거나 시간적 간격을 두고 단층영상을 획득하는 경우가 많다. 3차원 영상정합은 비교하고자 하는 두 영상을 하나의 3차원 좌표 공간으로 지도화하는 것이며, 크게 마커기반 정합과 특징기반 정합으로 분류된다. 뇌 영상의 3차원 정합은 뇌 수술부위 선정, 뇌 기능 연구, 뇌 지도화 연구 등에서 시각적 분석과 정량적 분석에서 중요한 위치를 차지한다. 본 논문에서는 뇌의 단층영상에 대하여 흔히 사용되고 있는 3차원 정합인 마커기반 정합법과 특징기반 정합법에 대하여 소개하고 이에 대한 비교 고찰을 행하고자 한다.

• 정보처리학회논문지B
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• 제9B권5호
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• pp.625-634
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• 2002

본 논문에서는 베이지안 망을 기초로 불임환자의 임상 데이터에 대한 다양한 분석 실험을 전개하였다. 이 실험을 통해 임신여부에 영향을 주는 요인들간의 상호의존성을 분석해보고, 또 NBN, BAN, GBN 등 제약조건이 다른 다양한 유형의 베이지안 망 분류기들의 분류성능을 서로 비교해보았다. 그리고 우리는 이와 같은 실험을 통해 임신가능여부(Clin)에 직접적인 영향을 미치는 중요한 요인들로 증상(IND), 약물치료법(stimulation), 여성의 나이(FA), 미세조작 난자의 수(ICT), Wallace 사용여부(ETM) 등 5개의 특성들을 가려낼 수 있었고, 이 요인들간의 상호 의존성도 찾아낼 수 있었다. 또 서로 다른 유형의 베이지안 망 분류기들 중에서 요인들간의 상호의존관계를 허용하는 좀 더 일반적인 BAN과 GBN 등이 그렇지 못한 NBN에 비해 상대적으로 더 높은 분류 성능을 보여준다는 것을 확인하였다. 또 결정트리와 k-최근접 이웃과 같은 다른 분류기들과의 성능 비교를 통해, 임상 데이터의 특성상 확률적 표현과 추론에 기초한 베이지안 망 분류기들이 보다 높은 성능을 보여준다는 사실도 확인할 수 있었다. 또 본 논문에서는 클래스 노드의 Markov blanket에 속한 특성들로 특성집합을 축소하는 것을 제안하고, 실험을 통해 이 특성 축소방법이 베이지안 망 분류기들의 성능을 높여 줄 수 있는지 알아보았다.

• Korean Journal of Radiology
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• 제22권3호
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• pp.334-343
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• 2021

Objective: We aimed to develop a prediction model for diagnosing severe aortic stenosis (AS) using computed tomography (CT) radiomics features of aortic valve calcium (AVC) and machine learning (ML) algorithms. Materials and Methods: We retrospectively enrolled 408 patients who underwent cardiac CT between March 2010 and August 2017 and had echocardiographic examinations (240 patients with severe AS on echocardiography [the severe AS group] and 168 patients without severe AS [the non-severe AS group]). Data were divided into a training set (312 patients) and a validation set (96 patients). Using non-contrast-enhanced cardiac CT scans, AVC was segmented, and 128 radiomics features for AVC were extracted. After feature selection was performed with three ML algorithms (least absolute shrinkage and selection operator [LASSO], random forests [RFs], and eXtreme Gradient Boosting [XGBoost]), model classifiers for diagnosing severe AS on echocardiography were developed in combination with three different model classifier methods (logistic regression, RF, and XGBoost). The performance (c-index) of each radiomics prediction model was compared with predictions based on AVC volume and score. Results: The radiomics scores derived from LASSO were significantly different between the severe AS and non-severe AS groups in the validation set (median, 1.563 vs. 0.197, respectively, p < 0.001). A radiomics prediction model based on feature selection by LASSO + model classifier by XGBoost showed the highest c-index of 0.921 (95% confidence interval [CI], 0.869-0.973) in the validation set. Compared to prediction models based on AVC volume and score (c-indexes of 0.894 [95% CI, 0.815-0.948] and 0.899 [95% CI, 0.820-0.951], respectively), eight and three of the nine radiomics prediction models showed higher discrimination abilities for severe AS. However, the differences were not statistically significant (p > 0.05 for all). Conclusion: Models based on the radiomics features of AVC and ML algorithms may perform well for diagnosing severe AS, but the added value compared to AVC volume and score should be investigated further.

• 한국의사학회지
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• 제13권1호
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• pp.3-19
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• 2000

Seo Dai-chun emphasized the importance of attack on the miasma and created a school to follow classical medical books such as "Nai Kyung"and "Sang Han Ron". Intimate connection between the theory and clinical experience was an unique feature and future generation including Chin Su-won and Wang Tai-lim were deeply influenced. His medical theology and medical case is presented in "Eui Hak Won Ryu Ron"and "Hoi Kye Eui An".

• Advances in pediatric surgery
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• 제10권1호
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• pp.39-42
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• 2004

Thymolipoma is a rare benign mediastinal tumor, composed of mature fatty and thymic tissues. A 9-year-old boy was referred with a one-month history of neck swelling. Preoperative computed tomography scan and fine needle aspiration biopsy suggested thymolipoma. Despite it being rare, thymolipoma should be considered in the differential diagnosis of mediastinal tumors. Characteristics of its clinical feature and radiological findings that can differentiated it from other mediastinal tumors are discussed with a review of the literatures.

• Journal of Chest Surgery
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• 제21권3호
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• pp.601-606
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• 1988

Bronchial carcinoid was classified as one of the bronchial adenoma group and it was regarded as benign tumor because of its uniform histologic feature, predictable clinical course and good survivability after surgical resection. But recently, many authors described that bronchial carcinoid has low grade malignancy for its lymphatic spread and distant metastasis, especially atypical carcinoid. We had a case of typical bronchial carcinoid in 20 year old female patient, and successful operation was performed by bilobectomy of middle and lower lob of right lung. Postoperative course was uneventful and discharged without any complication.

• Journal of Korean Neurosurgical Society
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• 제43권1호
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• pp.45-47
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• 2008

Fungal infections of the spine are relatively uncommon. Moreover, cervical spondylodiscitis due to Candida albicans in non-immunocompromised patient is very rare. We report a case of Candida spondylodiscitis in a 64-year-old woman who complained of neck pain. The clinical feature and treatment option are presented with a review of pertinent literatures.

• 대한치과의사협회지
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• 제20권11호통권162호
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• pp.971-974
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• 1982

The authors observed a case of Cherubism from 8 year-old boy who visited the Dept. of Oral Radiology in S.N.U.H. The patient complained of painless, bilateral swelling on mandibular angle area. Radiologically, sharply defined multiocular radiolucencies are found at both mandibular angle and maxillary posterior area. Another lesion is found at mandibular symphysis area. Interestingly, patient did not show 'look toward heaven' appearance in spite of maxillary involovment. The purpose of this paper if to describe the characteristic clinical, radiological and histopathological feature of the patient without familial involvement.

• 생물정신의학
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• 제4권1호
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• pp.29-35
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• 1997

Many disorders in neuropsychiatric field demonstrate variable motor disturbances as their clinical feature or in their courses of illness and also due to psychopharmacological treatment. Although association of such motor disturbances with the pathophysiological aspect of various neuropsychiatric illness are still lacking, some form of motor disturbance offer a window through which pathophysiologic mechanism of such illnesses can be viewed. Cognitive control of motor functions are briefly reviewed in this article and the importance and method of motor function assessment in major neuropsychiatric disorders are also discussed. Motor dysfunction of major neuropsychiatric illness such as schizophrenia and mood disorders may offer a chance of a deeper understanding on the pathophysiologic aspect of their clinical presentation.

• Journal of Chest Surgery
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• 제25권3호
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• pp.330-334
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• 1992

Takayasu`s arteritis is a non-specific arteritis involving the aorta and its major branches. Because of the complexity in the feature of vessel involvement, it represents various clinical presentations according to the sites of involvement. In general, the medical and the surgical treatment of this progressive disease are known to be unsatisfactory but the surgical treatment can provide symptomatic relief and prolong life in selected cases. Recently we experienced one case of Takayasu`s arteritis involving the aortic arch and its major branches. A 45 year-old male patient admitted with the complaints of dizziness, headache, visual disturbance and coldness of upper extremities. Ascending aortogram revealed total occlusion of innominate artery and near total occlusion of left common carotid artery at the site of origin of both vessels. Under the clinical diagnosis of Takayasu`s arteritis, aorto-bicarotid-right subclavian bypass was performed. Postoperative course was uneventful and most of symptoms were relieved except mild residual visual disturbance.