• The Journal of Korean Society for Radiation Therapy
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• v.13 no.1
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• pp.109-112
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• 2001

1. 목적 : head and neck cancer 환자의, C-T 영상을 이용한 방사선치료계획시 치과 보철물에 의해 발생하는 artifact가 선량 계산에 미치는 영향을 분석하고자 한다. 2. 재료 및 방법:두 경부와 유사한 크기의 Polystyrenes Phantom ($20{\times}20{\times}25cm^3$) 을 제작하고, 팬톰내에 금으로 인공보철물을 제작하여 보철물 부착 전.후를 C-T Scan (High Speed Advantage, GE, US) 하였다. artifact에 의한 영향을 쉽게 분석하기위해 팬톰내에 다른 구조물은 만들지 않았으며 두가지 방법으로 얻어진 영상을 이용하여 조사면의 크기와 조사 방향을 변화 시켜 가며 1문 조사(SSD 100 cm)에 의한 치료 계획(3D RTP system, Prowess, US)을 수립하여 기준점(5,10 cm depth)에서의 선량 변화를 비교 분석하였다. 아울러 3회 반복 scan하여 artifact에 발생 유형과 CTNo을 이용한 density을 분석하였다. 3. 결과: C-T Scan으로 얻어진 image 상에 나타난 Artifact는 CT no $-1000{\sim}+2775$(기준 $-1000{\sim}+3700$)까지의 다양한 값을 가지며 보철물을 기준으로 방사형태로 분포하였다. artifact가 선량 계산에 미치는 영향을 분석한 결과 보철물 사용시 5cm깊이의 기준점에서 절대선량은 평균 $+1.5{\pm}2.8\%$, 10 cm 깊이에서는 $+1.8{\pm}3.5\%$의 오차를 보였다. 조사방향에 의한 오차는 artifact에 대해 측면 조사한(gantry $270^{\circ}$)경우에서 높게 관찰되었다. 4. 결론: 두 경부 종양의 방사선 치료시 치과 보철물에 의한 artifact는 흔히 관찰가능하며 본 실험을 통해 다양한 형태와 다양한 density을 가짐을 알수있었다. 영상에 나타난 정도에 비해 선량계산에 미치는 평균 오차는 낮게 평가되었지만 조사 방향과 보철물의 위치에 따라 변동이 크게 나타날 수 있어 치료 계획시 가능한 artifact의 영향을 적게 받는 빔의 선택이 정확한 선량 계산에 도움을 줄 것으로 사료된다.

• Journal of Korean Neurosurgical Society
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• v.59 no.2
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• pp.129-136
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• 2016

Objective : The purpose of this study was to figure out the radiologic findings and risk factors related to adjacent segment degeneration (ASD) after anterior cervical discectomy and fusion (ACDF) using 3-year follow-up radiography, computed tomography (CT), and magnetic resonance image (MRI). Methods : A retrospective matched comparative study was performed for 64 patients who underwent single-level ACDF with a cage and plate. Radiologic parameters, including upper segment range of motion (USROM), lower segment range of motion (LSROM), upper segment disc height (UDH), and lower segment disc height (LDH), clinical outcomes assessed with neck and arm visual analogue scale (VAS), and risk factors were analyzed. Results : Patients were categorized into the ASD (32 patients) and non-ASD (32 patients) group. The decrease of UDH was significantly greater in the ASD group at each follow-up visit. At 36 months postoperatively, the difference for USROM value from the preoperative one significantly increased in the ASD group than non-ASD group. Preoperative other segment degeneration was significantly associated with the increased incidence of ASD at 36 months. However, pain intensity for the neck and arm was not significantly different between groups at any post-operative follow-up visit. Conclusion : The main factor affecting ASD is preoperative other segment degeneration out of the adjacent segment. In addition, patients over the age of 50 are at higher risk of developing ASD. Although there was definite radiologic degeneration in the ASD group, no significant difference was observed between the ASD and non-ASD groups in terms of the incidence of symptomatic disease.

• Progress in Medical Physics
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• v.5 no.1
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• pp.3-12
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• 1994

Purporse : It is known that detection of calcification by MRI is difficulty in intracranial calcified lesions, but author tried to evaluate the signal intensity image of calcification by MR with experimental model. Subjects & Methods : Author analyzed and compared with values of calcium carbonate and hydroxyapatite phantoms by each concentration (10, 20, 30, 40, 50%) and size(1-10mm), measured ROI attenuating from CT and MRI(TlWI & T2WI). Results : The high concentration of calcium carbonate is, the lower the signal intensity of calcium carbonate phantom is both T1 & T2WI. For concentration of Hydroxyapatite of up to 30% by weight the signal intensity on standard T1 weighted images increased but subsequently decreased. Hyperintensity does not preclude calcification as a cause of the signal alteration-an observation that all radiologists interpreting MR images need to be aware of. Conclusion: The signal intensity of intracranial calcification is various on MR imaging in concerning with components, concentration, & size of calcification, and especially high signal intensity of intracranial calcification noted differencial diagnosis.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2002.06a
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• pp.89-104
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• 2002

유전체연구사업단은 국내에서 발병 및 사망빈도가 가장 높은 위암과 간암의 퇴치를 목적으로 국가적 특목전략사업으로 연구를 추진하고 있다. 이와 별도로 보건복지부에서는 22개의 중요 질병별 유전체 연구센터를 전국적으로 추진하고 있다. 따라서, 연구가 성공적으로 진행되면 각 연구소에서 독자적으로 개발하여 제공하는 생명정보의 양은 거의 무한에 이를 것이다. 그러나 생명정보는 환자진료에 도움을 주기 위해서는 궁극적으로 임상정보와 함께 유기적으로 통합되어야 한다. 임상정보와의 통합을 위해서는 의료기관의 진료정보와 연구소의 생명정보가 연계되어 엄밀한 임상실험이 추가적으로 실시되어야 한다. 뿐만 아니라 생명정보학의 발전을 위해서는 연구대상의 임상정보가 공유되어야 한다. 유전체정보를 이용하는 생명정보학(Bioinformatics)은 각 국가마다 전략사업으로 간주하여 막대한 투자가 이루어지는 새로운 분야이다. 현재 선진국에서 개발 사용 중인 시스템의 연간 사용료가 고가이므로 국내 도입은 거의 불가능하거나 또는 매우 비효율적이다. 유전체 또는 생명정보의 임상활용 및 생명정보연구를 위한 임상정보 공유를 위해서는 우선 다음의 사항이 개발되어야 한다. 1) 다음과 같은 개별환자의 정보를 각 의료기관에서 제공 받아 저장 활용한다. - 진찰 및 임상소견, 수술기록, 경과기록, 검사결과 (임상병리, 해부병리, 방사선 등), - 영상정보 (X-ray, CT, MRI, 초음파, 전자현미경, 그래픽 등), - 환자개인기록(병력, 과거력, 가족력, 알러지 등), - 예방접종 기록 2) 각 연구소에서 첨단기술을 이용하여 개발되는 생명정보를 임상에 활용하기 위해서는 유전체연구센타와 병원간에 임상정보와 유전체 분석정보의 공유가 필수적으로 발생하게 됨으로, 유전체 정보와 임상정보의 통합은 미래 의료환경에 필수기능이 될 것이다. 3) 각 생명공학 연구소에서 사용하는 첨단 분석 장비와 생명공학 정보시스템의 자동 연계가 필요하다. 현재 국내에는 전국적인 초고속정보망이 가동되어 웹을 기반으로 하는 생명정보의 공유는 기술적으로 문제가 될 수 없으나 임상정보의 유전체연구에 그리고 유전체연구정보의 임상활용은 다양한 문제를 내포하고 있다. 이에 영상을 포함한 환자정보의 유전체연구센터와 병원정보시스템과의 효율적인 연계통합 운영을 위해 국내에서는 초기 도입단계에 있는 국제적인 보건의료정보의 표준인 Health Level 7 (textural information 공유), DICOM (image 및 wave 공유), 관련 ISO표준, WHO의 ICD9/10 (질병분류), LOINC (검사 및 관련용어), SNOMED International (의학용어) 등을 활용하여야 한다.

• Archives of Plastic Surgery
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• v.37 no.5
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• pp.633-638
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• 2010

Purpose: Orbital bone is one of the most complex bones in the human body. When the patient has a fracture of the orbital bone, it is difficult for the surgeon to restore the fractured orbital bone to normal anatomic curvature because the orbital bone has complex curvature. We developed a rapid prototyping model based on a mirror image of the patient's 3D-CT (3 dimensional computed tomography) for accurate reduction of the fractured orbital wall. Methods: A total of 7 cases of large orbital wall fracture recieved absorbable plate prefabrication using rapid prototyping model during surgery and had the manufactured plate inserted in the fracture site. Results: There was no significant postoperative complication. One patient had persistent diplopia, but it was resolved completely after 5 weeks. Enophthalmos was improved in all patients. Conclusion: With long term follow-up, this new method of orbital wall reduction proved to be accurate, efficient and cost-effective, and we recommend this method for difficult large orbital wall fracture operations.

• Pediatric Infection and Vaccine
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• v.23 no.2
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• pp.143-148
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• 2016

Lemierre syndrome is a rare disease involving multiple organs affected by septic emboli following oropharyngeal infection. After the introduction of penicillin in the 1940s, it became a "forgotten" disease. However, due to the development of diagnostic image modalities including neck computed tomography (CT) scan, the number of published reports of Lemierre syndrome and diagnosis has been increasing since the 1990s. In this report, we describe a case of Lemierre syndrome, following oropharyngeal infection in a 16-year-old patient, who manifested with persistent fever and neck stiffness. Neck ultrasonography confirmed thrombus formation in the right internal jugular vein without definite evidence of septic emboli to other organs. After the three-week-long antibiotics therapy was completed, the thrombus in the right internal jugular vein finally disappeared.

• Journal of Korean Neurosurgical Society
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• v.48 no.2
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• pp.139-144
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• 2010

Objective : We report our surgical experience in the treatment of 16 consecutive patients with benign craniovertebral junction (CVJ) tumor, observed from 2003 to 2008 at our department. Methods : We had treated 6 foramen magnum meningiomas, 6 cervicomedullary hemangioblastomas, 1 accessory nerve schwannoma, 1 hypoglossal nerve schwannoma, 1 C2 root schwannoma, and 1 cavernous hemangioma. Clinical results were evaluated by Karnofsky Performance Scale (KPS) and all patients underwent preoperative neuroradiological evaluation with computed tomography (CT) and magnetic resonance image (MRI). Angiography was performed in 15 patients and preoperative embolization was done in 2 patients. Results : Five far-lateral, 1 supracondylar and 10 midline suboccipital approaches were performed. Gross total removal was achieved in 15 cases (94%) and subtotal removal in 1 patient (6%). None of the patients required occipitocervical fusion. Radiological follow-up showed no recurrence in cases totally removed. Postoperative decrease of KPS scores was recorded in only 1 patient. The treatment of cervicomedullary solid hemangioblastoma presented particular issues : by preoperative embolization, we removed tumor totally without an excessive bleeding or brainstem injury. In one of foramen magnum meningioma, we carried out subtotal removal due to hard tumor consistency and encasement of neurovascular structures. Conclusion : The choice of surgical approaches and the extent of bone resection should be defined according to the location and size of individual tumors. Moreover, we emphasize that preoperative neuroradiological evaluations on presumptive tumor type could be helpful to the surgeon in tailoring the technique and providing the required exposure for different lesions, without unnecessary surgical steps.

• The Korean Journal of Health Service Management
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• v.4 no.1
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• pp.145-156
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• 2010

The purpose of this study is one of high price medical equipment wished to grasp propriety factor about the MRI introduction, analyzing payability through cost accounting into compensation. It was investigated from January 1 to December 31, 2007 about the MRI of a General Hospital. Expectation availability was 23.2 cases, but actual availability did achievement more than 196.1% with 45.5 items. It is estimated that there are a lot of occurrence cases because great reasons that actual availability increases more than expectation availability is excellent resolving power than a CT, and is device that prefer to reason back that radiation damage is less in person body. The followings show the main results of this study. 1. The MRI was construed in order of cost accounting, wave and personnel expenses 45.4%, administrative expenses 53.0%, and material costs 1.6%. 2. According to CVP (Cost-volume-profit) analysis, BEP (Break Even Point) profit is 173,931,428 won for 11 months, and break even usage number of items are 37.5 cases, and separation usage number of items were confirmed by 1.4 cases. Therefore, was construed that can achieve BEP within 11 months though usage number of items keeps 1.4 items day to create the MRI's hospital operation profit. 3. Estimated limit profitability appears high by 96.7%, exceed fixed charges even if when is non-benefit and when it is benefit consider variable, is judged that the MRI's addition induction helps in hospital management enhancing earning rates.

• Journal of Yeungnam Medical Science
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• v.4 no.1
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• pp.1-15
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• 1987

Magnetic Resonance (M.R.) is rapidly emerging technique that provides high quality images and potentially provides much more diagnostic information than do conventional imaging modalities. M.R.I. is conceptually quite different from currently used imaging methods. The complex nature of M.R.I. allows a great deal of flexibility in image product ion and available information, and key points are as follows. 1. M.R.I. offers a non-invasive technique with which to gene rate in vivo human images without ionizing radiation and with no known adverse biological effects. 2. Imaging mechanism of M.R.I. is quite different from conventional imaging modality and for more accurate diagnostic application, It is necessary for physician to understand imaging mechanism of M.R.I. 3. M.R. makes available basic chemical parameters that may provide to be useful for diagnostic medical imaging and more specific pathophysiologic information which are not available by alternate techniques. 4. M.R. can be produced by number of different methods. This flexibility allows the imaging technique to be applicated for particular clinical purpose. Multiplanar and three dimensional imaging may extend the imaging process beyond the single section available with current CT. 5. Future directions include efforts to; a. Further development of hard ware b. More fasternning scan time c. Respiratory and cardiac gated imaging d. Imaging of additional nuclei except hydrogen e. Further development of contrast media f. M.R. in vivo spectroscopy g. Real time M.R. imaging.

• Journal of Korean Neurosurgical Society
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• v.42 no.3
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• pp.168-172
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• 2007

Objective : Hirabayashi's open-door laminoplasty is a good procedure to use to treat patients with myelopathy of the cervical spine; however, the authors have experienced problems in maintaining an open-window in cervical spines after the surgery. The authors developed a modified method of the expanded open-door laminoplasty and compared the radiological and clinical results with those of the classical method. Methods : In the modified method, wiring fixation with lateral mass screws on the contra lateral-side instead of fixing the paraspinal muscle or facet joint, as in the classical methods, was used in the open window of the cervical spine. Fifteen patients with cervical myelopathy were treated using the classical method and 12 patients were treated using the modified method. Preoperative and postoperative clinical conditions were assessed according to the Japanese Orthopedic Association (JOA) score. The radiological results were compared with the preoperative and postoperative computed tomography (CT) findings. Results : In both methods, the clinical results revealed a significant improvement in neurological function (p<0.001). Image analysis revealed that the cervical canals were continuously expanded in patients treated using the modified methods. However, authors have observed restenosis during the follow-up periods in 4 patients treated using the original method. Progression to deformity and spinal instability were not observed in any of the patients in the radiological results. Conclusion : Although analysis with a larger population and a longer follow-up period needs to be undertaken, our modified open-door laminoplasty has shown an advantage in better maintaining an open window in comparison with the Hirabayashi's open-door laminoplasty.