• 대한두개안면성형외과학회지
• /
• 제12권1호
• /
• pp.33-36
• /
• 2011

Background: In a frontal sinus reconstruction, the literature primarily recommends a surgical approach for definite treatment with the exception of for anterior wall fractures with no dislocation. Many studies have assessed a range of methods for the reduction of frontal sinus fractures. This paper presents a case, in whom the anterior wall of the frontal sinus was reconstructed using an outer table calvarial bone graft in an en bloc manner. Patient and methods: A 36-year-old male visited the emergency room with a heavy injury to the forehead. He was diagnosed with fractures of the anterior and posterior wall of the frontal sinus. The neurosurgeon removed the fractured area and repaired the meninges. Afterwards, cranialization was performed and the opening of the nasofrontal duct was obstructed. After fixing the removed bone to its original location, all fragments of fractured anterior wall were purged out and the anterior wall reconstructed using an en bloc calvarial bone graft. Results: In the post-operative 8 months period, there were no complications, the round contour of the forehead was expressed well and the patient was satisfied with the result. Conclusion: There are many methods for reconstructing the anterior wall of the frontal sinus. On the other hand, in cases of large fracture sites with many fractured bone fragments, en bloc harvesting of the outer table calvarial bone could be a better choice than making use of only plates and screws because this method shows a good results in terms of aesthetics with a low complication rate.

• 한국추진공학회지
• /
• 제16권4호
• /
• pp.70-79
• /
• 2012

공력학적 성능을 평가하는 대형 유동 시험장치에서 시험체 입구로 들어가는 유체의 압력, 온도, 유량등은 시험체의 성능 계산에 필수적인 항목이므로, 이 값들을 정확하게 측정하는 것이 중요하다. 본 논문에서는 벨마우스와 레이크를 사용하여 보정 유량 범위가 5 ~ 8 kg/s인 대용량 유량을 계측하는 방법을 연구하였다. 벨마우스는 ISO Standard를 따라 0.5% 정확도를 만족할 수 있도록 설계하였고, 레이크는 등면적으로 배치하도록 설계하였다. 총 9 회의 서로 다른 조건의 시험을 분석한 결과 레이크 레이놀즈 수와 유량값의 비가 1차 함수 관계에 있음을 확인하였고, 이 관계식을 이용하여 레이크의 유량값을 벨마우스의 값을 기준으로 최대 -0.507%, 평균 -0.000274% 오차율로 보정할 수 있었다.

• Journal of Oral Medicine and Pain
• /
• 제47권3호
• /
• pp.148-151
• /
• 2022

Obstructive sialadenitis, one of the diseases that most frequently causes swelling and pain in the salivary glands, is mainly caused by structural obstructions. Sialolithiasis is the most frequent cause of the disease, and other causes include calculus formation, duct strictures, foreign bodies, and anatomical variations. Although there is a possibility that facial fillers directly block the salivary ducts, no cases of obstructive sialadenitis associated with them have been reported yet. We report the case of a 34-year-old female patient who complained of recurrent swelling and pain in the left buccal mucosa. She had undergone facial filler injection procedures on her facial area for cosmetic purposes several years before. Based on the findings of magnetic resonance imaging (MRI) and MR sialography, she was diagnosed with obstructive sialadenitis due to facial fillers. Through this case, we should remember to obtain a thorough history including filler treatments in the case of parotid gland swelling. We also suggest proper utilization of advanced imaging such as MRI in evaluating the location of facial fillers.

• 대한영상의학회지
• /
• 제81권5호
• /
• pp.1069-1082
• /
• 2020

복부 영상 영역에서는 새로운 건강보험 보장성 강화 대책으로 인하여 2018년 4월 1일 상복부 초음파, 2019년 2월 1일 하복부 초음파와 2019년 11월 1일 복부 MRI가 순서대로 급여 확대되었다. 많은 환자들이 건강보험 급여 혜택을 보게 되었으며 간경화, 담낭용종, 간선종, 이형성 결절, 췌장 낭종과 자가면역성 췌장염, 담석 등이 건강보험에 포함되었다. 그러나 급여화로 인해 각 검사의 적응증, 추적검사 가능 질환과 적용 횟수 등이 보다 복잡해졌으며 획득하여야 할 표준영상과 판독소견서의 양식이 지정되었으며, 따라서 외래나 병실에서 검사를 처방하고 검사실에서 검사를 시행할 때 주의해야 할 필요가 있다.

• Archives of Plastic Surgery
• /
• 제51권1호
• /
• pp.130-134
• /
• 2024

Refractory chylous ascites can cause significant nutritional and immunologic morbidity, but no clear treatment has been established. This article introduces a case of a 22-year-old female patient with an underlying lymphatic anomaly who presented with refractory chylous ascites after laparoscopic adnexectomy for ovarian teratoma which aggravated after thoracic duct embolization. Ascites (>3,000 mL/d) had to be drained via a percutaneous catheter to relieve abdominal distention and consequent dyspnea, leading to significant cachexia and weight loss. Two sessions of hybrid lymphovenous anastomosis (LVA) surgery with intraoperative mesenteric lymphangiography guidance were performed to decompress the lymphatics. The first LVA was done between inferior mesenteric vein and left para-aortic enlarged lymphatics in a side-to-side manner. The daily drainage of chylous ascites significantly decreased to 130 mL/day immediately following surgery but increased 6 days later. An additional LVA was performed between right ovarian vein and enlarged lymphatics in aortocaval area in side-to-side and end-to-side manner. The chylous ascites resolved subsequently without any complications, and the patient was discharged after 2 weeks. The patient regained weight without ascites recurrence after 22 months of follow-up. This case shares a successful experience of treating refractory chylous ascites with lymphatic anomaly through LVA, reversing the patient's life-threatening weight loss. LVA was applied with a multidisciplinary approach using intraoperative mesenteric lipiodol, and results showed the possibility of expanding its use to challenging problems in the intraperitoneal cavity.

• Korean Journal of Radiology
• /
• 제22권5호
• /
• pp.714-724
• /
• 2021

Objective: To evaluate the value of ¹⁸F-fluorodeoxyglucose PET/MRI added to contrast-enhanced CT (CECT) in initial staging, assessment of resectability, and postoperative follow-up of biliary tract cancer. Materials and Methods: This retrospective study included 100 patients (initial workup [n = 65] and postoperative follow-up [n = 35]) who had undergone PET/MRI and CECT for bile duct or gallbladder lesions between January 2013 and March 2020. Two radiologists independently reviewed the CECT imaging set and CECT plus PET/MRI set to determine the likelihood of malignancy, local and overall resectability, and distant metastasis in the initial workup group, and local recurrence and distant metastasis in the follow-up group. Diagnostic performances of the two imaging sets were compared using clinical-surgical-pathologic findings as standards of reference. Results: The diagnostic performance of CECT significantly improved after the addition of PET/MRI for liver metastasis (area under the receiver operating characteristic curve [A_z]: 0.77 vs. 0.91 [p = 0.027] for reviewer 1; 0.76 vs. 0.92 [p = 0.021] for reviewer 2), lymph node metastasis (0.73 vs. 0.92 [p = 0.004]; 0.81 vs. 0.92 [p = 0.023]), and overall resectability (0.79 vs. 0.92 [p = 0.007]; 0.82 vs. 0.94 [p = 0.021]) in the initial workup group. In the follow-up group, the diagnostic performance of CECT plus PET/MRI was significantly higher than that of CECT imaging for local recurrence (0.81 vs. 1.00 [p = 0.029]; 0.82 vs. 0.94 [p = 0.045]). Conclusion: PET/MRI may add value to CECT in patients with biliary tract cancer both in the initial workup for staging and determination of overall resectability and in follow-up for local recurrence.

• 한국산학기술학회논문지
• /
• 제12권2호
• /
• pp.1005-1012
• /
• 2011

본 연구에서는 혁신적인 연소시스템의 최적 연소조건을 도출하기 위해 반응기 내부 유동 특성, 온도분포, 속도분포 및 체류시간 등에 대해 전산유체역학(CFD)을 이용한 3차원 모사를 수행하였다. 연료 투입량 1.5 ton/hr, 체류시간 1.25초, 공기비 2.1의 조건에서 연소시킬 때 로의 출구의 면적가중(area-weighted) 평균온도는 $1,077^{\circ}C$로 나타나 에너지 회수 및 유해가스 처리에 적합한 온도임을 알 수 있었다. 배가스는 연소실 중앙부위에서 강한 선회류를 따라 최고속도 약 40~50 m/s로 덕트를 통해 배출되므로 연소실의 중심부에 강한 난류가 형성되어 연소 속도 및 연소 효율이 향상되는 것으로 나타났다. 본 시스템의 경우, 불완전 연소를 방지하고 또한 thermal NOx의 생성도 억제하기 위한 적정 조업조건은 공기비 1.9~2.1, 연료 투입량 1.25~1.5 ton/hr 정도인 것으로 나타났다.

• 방사성폐기물학회지
• /
• 제3권3호
• /
• pp.159-165
• /
• 2005

원자력 시설의 해체 시 발생되는 다양한 종류의 폐기물 중에서 배관류를 재활용하거나 처분하기 위해서는 배관 내부의 정확한 방사선학적인 오염 특성의 평가가 선행되어야 한다. 그러나 기존의 측정법인 survey-meter를 이용한 오염도의 직접 측정은 배관 내부와 같은 국소지역의 오염 특성을 정확하게 평가할 수 없으며, 간접법을 이용한 표면오염도 측정의 경우도 시료채취의 어려움뿐만 아니라 시료채취 시 작업자의 오염 가능성이 있기 때문에 적용성에 많은 문제점이 있다. 본 연구에서는 Monte Carlo 모사기법을 이용해 직경이 작은 배관 내부의 베타선 오염도를 측정하기 위하여 플라스틱 섬광체를 모사하였으며, 모사 결과에서 베타선 에너지를 효율적으로 측정할 수 있는 최적의 플라스틱 섬광체 두께 및 형상을 도출할 수 있었다. 이 전사모사 결과를 바탕으로 섬광체의 가공 및 배관 내부에서의 검출기 이송 문제를 고려해 검출기를 제작하였으며 그 특성을 평가하였다. 그 결과 배관 내부의 오염도 측정에 적합한 검출기 성능을 확인하였고, 파이프 내부처럼 국소 지역의 방사선학적 오염 특성 평가를 위한 검출기 개발 가능성을 확인하였다.

• 한국산학기술학회논문지
• /
• 제9권4호
• /
• pp.878-885
• /
• 2008

최근에 많은 수요와 각광을 받고 있는 디스플레이 장치에서 CRT는 곡면이며 무겁고 큰 부피 때문에 LCD, PDP, OLED와 같은 평판디스플레이(FPD)로 대체되고 있다. FPD는 $0.6\sim0.8mm$ 두께의 대면적 글래스에 여러 공정을 거친 후에 최종 제품 규격으로 절단하여 제작하기 때문에 글래스의 면적이 크면 클수록 FPD의 생산성이 높다는 밀접한 관계를 갖는다. 따라서 FPD 제조 업계에서는 글래스 면적을 증가시키기 위하여 노력하고 있으며, 예를 들면, 현재 8세대 LCD인 경우 약 $2,200mm\times2,600mm$의 면적을 가진다. 이러한 글래스를 이송하는 대표적인 장치로서 공기부상 컨베어시스템은 압축공기를 이용해서 FPD용 대면적 글래스 등을 약 $0.3\sim0.5mm$ 정도 부상시켜 비접촉으로 이송할 수 있는 장치이다. 이 때 글래스와 다공질판 표면 사이의 공기 유동이 모델링되고 해석되며, 이것으로부터 글래스의 공기부양 조건이 예측될 수 있다. 글래스를 이송시 전기공급 중단에 의하여 압축공기가 공급되지 않아 부상판과 접촉이 발생하였을 때, 자기윤활 특성을 가진 다공질판 위의 글래스는 1mm 홀을 많이 가진 사각덕트 부상판 위의 글래스와 조사, 비교된다.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제28권1호
• /
• pp.1-12
• /
• 2006

Pleomorphic adenoma is the most common benign tumor in salivary glands, and occurred in frequency of 60% in parotid gland tumors, and 50% in submandibular gland tumors, and 25% in sublingual gland tumors. Histopathologically, pleomorphic adenoma is composed of epithelial cells and mesenchymal tissues, and called 'mixed tumor' because of morphological divergency. The cell structures of luminal area are composed of polyhedral and cuboidal secretory epithelial cells and modified myoepithelial cells around it, and mesenchymal tissue is composed of some myoepithelial cells and stromal tissue. In stromal tissue, myxoid change, chondroid change, or hyalinization can be seen even if bone tissue. In many studies, tumor cells of pleomorphic adenoma containing modified myoepithelial cell participate in synthesis of glycosaminoglycans. In this study, tissue sample of pleomorphic adenoma of human salivary gland were obtained from 20 surgical specimens, and all specimens were routinely fixed in 10% formalin and embedded. Serial 4-8${\mu}m$ thick sections were cut from paraffin blocks. The histopathologic evaluation was done with light microscopy. And, with immunohistochemical staining, characteristics of glycosaminoglycan were observed. And, for biochemical analysis of glycosaminoglycan, isolation of crude glycosaminoglycan from tumor tissue and immuno-blot analysis were carried out. With transmission electromicroscopy, tumor cells and biologic behavior of pleomorphic adenoma were observed with distribution and expression of glycosaminoglycan in tumor cells, The results were obtained as follows: 1. In immunohistochemical study, chondroitin 4-sulfate is highly postively stained in myxoid stromal tissue, and chondroitin 6-sulfate is highly positively stained in chondroid mesenchymal tissue, both glycosaminoglycans are positively stained in non-luminal cell of ductal area. 2. Dermatan sulfate and keratan sulfate is positively stained in periductal non-luminal tumor cells. 3. In immunohistochemical study, heparan sulfate is weakly stained in luminal cells and non-luminal cells around duct, and chondroid mesenchymal tissue. 4. In transmission electromicroscopic view, the tumor cells are composed of modified myoepithelial cells, and contain many microfilaments and well developed rough endoplasmic reticulum. 5. In Immuno-Blot analysis, the expression of glycosaminoglycans is expressed mostly in chondroitin 6-sulfate and chondroitin 4-sulfate. From the results obtained in this study, tumor cells of pleomorphic adenoma are composed of modified myoepithelial cells, and glycosaminoglycans of chondroitin 4-sulfate and chondroitin 6-sulfate mostly participate in the development of pleomorphic adenoma, but dermatan sulfate, keratan sulfate and heparan sulfate glycosaminoglycans were expressed variably.