• 대한치과보철학회지
• /
• 제48권4호
• /
• pp.294-300
• /
• 2010

연구 목적: 컴퓨터-가이드 임플란트 수술은 전통적인 방법에 비해 여러 가지 장점을 가진다. 본 연구의 목적은 가이드 수술용 템플릿 제작을 위한 좌표동기화 5축 정밀가 공공정의 정확도를 범용 CAD 소프트웨어를 통해 역설계공학의 방법으로 평가하는 것이다. 연구 재료 및 방법: 악궁 형태의 모형에 거타퍼쳐 스타핑을 매식한 10 개의 모형을 만들고 상부에 실리콘 인상재를 이용하여 인공치은을 덮어 스타핑의 위치를 보이지 않게 가렸다. 모형의 하면에 동기화를 위한 좌표동기화 형상을 만든 뒤 Cone beam CT에서 3차원 영상을 얻었다. 임플란트 계획 소프트웨어의 CT 이미지 상에서 매식된 스타핑과 동일한 방향으로 스타핑의 1/2 깊이까지 가상의 시술계획을 하고, 스타핑의 방향벡터와 저지점 (1/2지점) 데이터를 석고모형의 영상으로 좌표동기화 하였다. 이후 모형하면의 좌표동기화 형상을 이용하여 가공기기상의 좌표로 좌표변환을 통해 가공좌표동기화를 하였다. 5축 밀링머신의 좌표동기화판에 모형을 고정한 후, 동기화된 가공데이터에 의거하여 스타핑과 동일한 직경의 드릴로 계획된 벡터와 깊이로 정확히 가공 하였다. 모델에 정확히 안착되는 인상트레이를 CT 장비에 미리 고정한 상태에서, 인상트레이에 모델을 적합하여 이미지를 획득한 뒤 3차원 재구성하는 방법으로 영상을 중첩하여 비교 분석하였다. SolidWorks (Dassault Systems, Concord, USA) 범용 CAD 상에 영상을 불러들여 역설계공학의 방법으로 실린더 상부, 하부의 중점에서의 위치편차와 각도편차를 조사하였다. 통계는 SPSS (release 14.0, SPSS Inc., Chicago, USA)를 이용하여 각 편차 사이의 상관관계를 분석하였다 ($\alpha$ = 0.05). 결과: 위치 편차로 인하여 모든 드릴 보어 (bore)에서 상부 1/2에 잔존하는 거타퍼쳐의 일부를 관찰할 수 있었다. 실험 모형상에서 계획된 이미지와 드릴링 후CT에서 역설계를 거친 이미지 사이의 위치편차는 상부에서 0.31 (0.15 - 0.42) mm, 하부에서 0.36 (0.24 - 0.51) mm, 각도편차는 1.62 (0.54 - 2.27)$^{\circ}$이었다. 실린더 상부와 하부 위치 편차는 양의 상관관계를 가졌다 (Pearson Correlation Coeffocient = 0.904, P= .013). 결론: 좌표동기화 5축 정밀가공 공정은 가이드 수술용 템플릿을 제작하는 데에 적합한 정확도를 가진다.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제38권
• /
• pp.37.1-37.5
• /
• 2016

Background: The dimensions and shape of the forehead determine the esthetics of the upper third of the face. Korean young people consider a broad and smooth, rounded forehead more attractive. As a result, frontal augmentation becomes more popular in patients with dentofacial deformities. Various surgical procedures and materials have been used in frontal augmentation surgery, with associated advantages and disadvantages. Silicone is a good candidate for frontal augmentation. The author presents two cases of esthetic frontal augmentation with a prefabricated silicone implant in female patients with dentofacial deformities. Case presentation: In case 1, a 24-year-old female patient underwent frontal augmentation surgery with simultaneous maxillomandibular and zygomatic osteotomies to correct facial asymmetry. A silicone implant was fabricated preoperatively using a positive template stone mold of her forehead. In case 2, a 23-year-old female patient underwent total facial contouring surgery including frontal augmentation for improved facial esthetics. A computed tomography (CT)-guided rapid prototype (RP) model was used to make the silicone implants. The operative procedure was safe and simple, and the silicone implants were reliable for a larger degree of frontal augmentation. Six months later, both patients had recovered from the surgery and were satisfied with their frontal shape and projection. Conclusions: Frontal augmentation with silicone implants can be an effective adjuvant strategy to improve facial esthetics in patients with a flat and narrow forehead who undergo orthognathic reconstruction or total facial contouring surgery.

• Tuberculosis and Respiratory Diseases
• /
• 제79권2호
• /
• pp.98-100
• /
• 2016

We present a rare case of critically compromised airway secondary to a massively dilated sequestered colon conduit after several revision surgeries. A 71-year-old male patient had several operations after the diagnosis of gastric cancer. After initial treatment of pneumonia in the pulmonology department, he was transferred to the surgery department for feeding jejunostomy because of recurrent aspiration. However, he had respiratory failure requiring mechanical ventilation. The chest computed tomography (CT) scan showed pneumonic consolidation at both lower lungs and massive dilatation of the substernal interposed colon compressing the trachea. The dilated interposed colon was originated from the right colon, which was sequestered after the recent esophageal reconstruction with left colon interposition resulting blind pouch at both ends. It was treated with CT-guided pigtail catheter drainage via right supraclavicular route, which was left in place for 2 weeks, and then removed. The patient remained well clinically, and was discharged home.

• Journal of Korean Neurosurgical Society
• /
• 제52권6호
• /
• pp.555-557
• /
• 2012

We report an uncommon case of a 45-year-old woman who presented with spontaneous rhinorrhea. A computed tomography (CT) scan of the head revealed an abnormally large sphenoid sinus associated with a parasellar bony defect (Sternberg's canal) through which magnetic resonance imaging could detect an encephalocele of the right temporal lobe. An endoscope-assisted trans-sphenoidal approach was performed and, with the aid of image guided surgery, reduction of the encephalocele was obtained and followed by surgical repair of the dural and bony defects. The postoperative course was uneventful and the cerebrospinal fluid fistula was closed as confirmed by the postoperative CT scan and by the absence of rhinorrhea. After three years of monitoring the patient remained asymptomatic.

• 품질경영학회지
• /
• 제34권4호
• /
• pp.40-50
• /
• 2006

The authors aimed to analyze the quality improvement efficiency of wound dressing with 2-octyl cyanoacrylate(2-OCA) in stereotactic image guided linear or sigmoid incisions in a cohort of consecutive craniotomy patients, and to compare clinical results with those of iodine-dressing and silk sutured patients underwent conventional craniotomy surgery with large pedicle flap incisions without stereotactic guidance. In methods, 26 patients were involved as the study group at one hospital. We retrospectively compared their results with those of 38 consecutive control patients at the same unit. The suggested new medical material, 2-octyl cyanoacrylate(2-OCA), resultantly decreased or prevented the contaminated fluid influx from scalp outside. The mean infection rate for the control group (7.89%) was relatively higher than that of the study group (3.85%). In addition, the use of stereotactic image guided craniotomy was significant to reduce operation time, to simplify operative procedures and to decrease potential risk factors.

• International Journal of Control, Automation, and Systems
• /
• 제4권1호
• /
• pp.30-41
• /
• 2006

The goal of this work is to develop and test a robot-assisted surgery system for spinal fusion. The system is composed of a robot, a surgical planning system, and a navigation system. It plays the role of assisting surgeons for inserting a pedicle screw in the spinal fusion procedure. Compared to conventional methods for spinal fusion, the proposed surgical procedure ensures minimum invasion and better accuracy by using robot and image information. The robot plays the role of positioning and guiding needles, drills, and other surgical instruments or conducts automatic boring and screwing. Pre-operative CT images intra-operative fluoroscopic images are integrated to provide the surgeon with information for surgical planning. Some experiments employing the developed robotic surgery system are conducted. The experimental results confirm that the system is not only able to guide the surgical tools by accurately pointing and orienting the specified location, but also successfully compensate the movement of the patient due to respiration.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2005년도 추계학술대회 논문집
• /
• pp.144-148
• /
• 2005

The goal of this work is to develop and test a robot-assisted surgery system for spinal fusion. The system is composed of a robot, a surgical planning system, and a navigation system. It plays the role of assisting surgeons for inserting a pedicle screw in the spinal fusion procedure. Compared to conventional methods fer spinal fusion, the proposed surgical procedure ensures minimum invasion and better accuracy by using robot and image information. The robot plays the role of positioning and guiding needles, drills, and other surgical instruments or conducts automatic boring and screwing. Pre-operative CT images and intra-operative fluoroscopic images are integrated to provide the surgeon with information for surgical planning. Several experiments employing the developed robotic surgery system are conducted. The experimental results confirmed that the system is not only able to guide the surgical tools by accurately pointing and orienting the specified location, but also successfully compensate the movement of the patient due to his/her respiration.

• Journal of Korean Neurosurgical Society
• /
• 제56권5호
• /
• pp.431-435
• /
• 2014

A fifty-year-old female non-smoker with no other specific medical history visited our institute. She complained of axial back pain with no other neurological deficit. Chest X-ray, chest computed tomography (CT) scan, CT-guided needle aspiration biopsy, whole-body positron emission tomography, spine CT and spine magnetic resonance image findings suggested NSCLC with epidermal growth factor receptor (EGFR) mutation, multiple brain metastases, and two isolated metastases to the T3 and L3 vertebral bodies. She underwent chemotherapy with gefitinib ($Iressa^{TM}$) for NSCLC and gamma knife surgery for multiple brain metastases. We performed a two-staged, total en bloc spondylectomy of the T3 and L3 vertebral bodies based on several good prognostic characteristics, such as the lack of metastases to the appendicular bone, good preoperative performance status, and being an excellent responder (Asian, never-smoker and adenocarcinoma histology) to EGFR inhibitors. Improved axial back pain after the surgery enabled her to walk with the aid of a thoracolumbosacral orthosis brace on the third postoperative day. Her Karnofsky performance status score (KPS) was 90 at the time of discharge and has been maintained to date 3 years after surgery. In selected NSCLC patients with good prognostic characteristics, we suggest that locally curative treatment such as total en bloc spondylectomy or radiosurgery should be emphasized to achieve longer term survival for the selected cases.

• 한국전자통신학회논문지
• /
• 제8권1호
• /
• pp.191-197
• /
• 2013

방사선과 의사들은 CT 및 MRI 스캐너로부터 얻어진 인체의 단면 영상을 연속적으로 보고 실제 3차원적으로 인체가 어떻게 구성되어 있는지를 상상하여 병변을 구별하는데, 의학영상을 이용한 인체 장기의 3차원 시각화는 2차원 형태의 인체 단면 영상들을 복잡한 알고리즘이나 고성능의 컴퓨팅 파워를 사용하여 실제 인체와 같이 3차원으로 재구성하여 보여준다. 단면 영상의 추적, 관심영역의 표시 및 추출등과 같은 2차원 영상분석은 시간이 많이 소모되고, 주관적일 수가 있으며, 수작업인 관계로 빈번한 에러가 발생하는 단점을 가지는데, 이와 같은 2차원 의료 영상 분석의 단점을 보완하기 위해 의학영상처리 기술과 접목한 3차원 의료 영상의 시각화는 필수적이라 할 수 있다. 명암값 임계치 방법, 영역확장(region growing) 방법, 윤곽선(contour) 추출 방법 및 변형모델(deformable model) 방법을 사용하여 인체의 각 장기를 분리하였으며, 텍스쳐분석(texture analysis)을 통하여 고안된 특징자를 이용하여 암 부분을 인식하는데 사용하였고, 원근투영(perspective projection) 및 볼륨 데이터의 표면을 렌더링하기 위해 마칭큐브(marching cube) 알고리즘을 사용하였다. 인체 및 분리된 장기에 대한 3차원 시각화는 방사선치료계획(radiation treatment planning), 외과 수술계획, 모의수술, 중재적(interventional)시술 및 영상유도수술(image guided surgery)에 효과적으로 사용될 수 있다.

• Archives of Plastic Surgery
• /
• 제40권5호
• /
• pp.610-615
• /
• 2013

Background Cephalometric analysis is essential for planning treatment in maxillofacial and aesthetic facial surgery. Although photometric analysis of the Korean nose has been attempted in the past, anthropometry of the deeper nasal structures in the same population based on computerized tomography (CT) has not been published. We therefore measured three anthropometric parameters of the nose on CT scans in our clinical series of patients. Methods We conducted the current retrospective study of a total of 100 patients (n=100) who underwent a CT-guided radiological measurement at our institution during a period ranging from January of 2008 to August of 2010. In these patients, we took three anthropometric measurements: the nasofrontal angle, the pyramidal angle, and the linear distance between the nasion and the tip of the nasal bone. Results The mean nasofrontal angle was $131.14^{\circ}$ in the male patients and $140.70^{\circ}$ in the female patients. The mean linear distance between the nasion and the tip of the nasal bone was 21.28 mm and 18.02 mm, respectively. The mean nasal pyramidal angle was $112.89^{\circ}$ and $103.25^{\circ}$ at the level of the nasal root, $117.49^{\circ}$ and $115.60^{\circ}$ at the middle level of the nasal bone, and $127.99^{\circ}$ and $125.04^{\circ}$ at the level of the tip of the nasal bone, respectively. Conclusions In conclusion, our data will be helpful in the preparation of silicone implants for augmentation and/or corrective rhinoplasty in ethnic Korean people.