• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.877-881
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• 2005

In this paper, a novel method for analyzing a textile fabric structure is proposed to segment each yarn of the textile fabric from voxel data made out of its X-ray computed tomography (CT) images. In order to segment the each yarn, directions of fibers, of which yarn consists, are firstly estimated by correlating the voxel with a fiber model. Second, each fiber is reconstructed by clustering the voxel of the fiber using the estimated fiber direction as a similarity. Then, each yarn is reconstructed by clustering the reconstructed fibers using a distance which is newly defined as a dissimilarity. Consequently, each yarn of the textile fabric is segmented from the voxel data. The effectiveness of the proposed method is confirmed by experimentally applying the method to voxel data of a sample plain woven fabric, which is made of polyester two folded yarn. The each two folded yarn is correctly segmented by the proposed method.

• Journal of Trauma and Injury
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• 제27권2호
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• pp.33-37
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• 2014

Central venous catheterization through a subclavian approach is indicated for some special purposes but it may cause many complications such as infection, bleeding, pneumothorax, thrombosis, air embolization, arrhythmia, myocardial perforation, and nerve injury. A case involving a mistaken central venous catheterization into the right vertebral artery through the subclavian artery is presented. A 33-year-old man who had deteriorated mentality after head injury underwent an emergency craniotomy for acute epidural hematomas on the right frontal and temporal convexities. His mentality improved rapidly, but he complained of continuous severe pain in the right posterior neck even though he had no previous symptom or past medical history of such pain. Three-dimensional cervical spine computed tomography (3D-CT) was performed first to rule out unconfirmed cervical injuries and it revealed a linear radiopaque material intrathoracically from the level of the 1st rib up to the level of C6 in the right vertebral foramen. An additional neck CT was performed, and the subclavian catheter was indwelling in the right vertebral artery through right subclavian artery. For the purpose of proper fluid infusion and central venous pressure monitoring, the subclavian vein catheterization had been performed in the operation room after general anesthesia induction before the craniotomy. Sufficient anatomical consideration and prudence is essential because inadvertent arterial cannulation at a non-compressible site is a highly risky iatrogenic complication of central venous line placement.

• 대한두개안면성형외과학회지
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• 제20권6호
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• pp.361-369
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• 2019

Background: Trauma is one of the most common causes of enophthalmos, and post-traumatic enophthalmos primarily results from an increased volume of the bony orbit. We achieved good long-term results by simultaneously using an anatomical absorbable implant and iliac bone graft to correct post-traumatic enophthalmos. Methods: From January 2012 to December 2016, we performed operations on seven patients with post-traumatic enophthalmos. In all seven cases, reduction surgery for the initial trauma was performed at our hospital. Hertel exophthalmometry, clinical photography, three-dimensional computed tomography (3D-CT), and orbital volume measurements using software to calculate the specific volume captured on 3D-CT (ITK-SNAP, Insight Toolkit-SNAP) were performed preoperatively and postoperatively. Results: Patients were evaluated based on exophthalmometry, clinical photographs, 3D-CT, and orbital volume measured by the ITK-SNAP program at 5 days and 1 year postoperatively, and all factors improved significantly compared with the preoperative baseline. Complications such as hematoma or extraocular muscle limitation were absent, and the corrected orbital volume was well maintained at the 1-year follow-up visit. Conclusion: We present a method to correct enophthalmos by reconstructing the orbital wall using an anatomical absorbable implant and a simultaneous autologous iliac bone graft. All cases showed satisfactory results for enophthalmos correction. We suggest this method as a good option for the correction of post-traumatic enophthalmos.

• Imaging Science in Dentistry
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• 제39권1호
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• pp.19-25
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• 2009

Purpose: To longitudinally observe the healing process of extracted socket and the alterations of the residual ridge in healthy adult dogs using cone beam CT (CBCT). Materials and Methods: The mandibular premolars of two beagle dogs were removed and the extraction sites were covered with the gingival tissue. CBCTs (3D X-ray CT scanner, Alphard vega, Asahi Co.) were taken at baseline and at 1 week interval for 12 weeks. Radiographic density of extracted wounds was measured on normalized images with a custom-made image analysis program. The amount of alveolar crestal resorption after the teeth extraction was measured with a reformatted three-dimensional image using CBCT. Bony healing pattern of extracted wound of each group was also longitudinally observed and analyzed. Results: Dimensional changes occurred during the first 6 weeks following the extraction of dogs' mandibular premolars. The reduction of the height of residual ridge was more pronounced at the buccal than at the lingual aspect of the extraction socket. Radiographic density of extracted wounds increased by week 4, but the change in density stabilized after week 6. New bone formation was observed at the floor and the peripheral side of extracted socket from week 1. The entrance of extracted socket was sealed by a hard-tissue bridge at week 5. Conclusion: The healing process of extracted wound involved a series of events including new bone formation and residual ridge resorption.

• Journal of International Society for Simulation Surgery
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• 제3권1호
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• pp.28-32
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• 2016

Background Congenital muscular torticollis (CMT) is a benign condition. With early diagnosis and appropriate management, it can be cured completely, leaving no residual deformity. However, long-standing, untreated CMT can lead to permanent craniofacial deformities and asymmetry.Methods Nineteen patients presented to the author with congenital muscular torticollis. Three dimensional computed tomography (3-D CT) scans was obtained upon patient’s admission. Adjustment of skull’s position to Frankfort horizontal plan was done. Cervical vertebral segmentation was done which allowed a 3D module to be separately created for each vertebra to detect any anatomical or positional changes.Results The segmented vertebrae showed an apparent anatomical changes, which were most noticeable at the level of the atlas and axis vertebrae. These changes decreased gradually till reaching the seventh cervical vertebra, which appeared to be normal in all patients. The changes in the atlas vertebra were mostly due to its intimate relation with the skull base, while the changes of the axis were the most significantConclusion Cervical vertebral segmentation is a reliable tool for isolation and studying cervical vertebral pathological changes of each vertebra separately. The accuracy of the procedures in addition to the availability of many software that can be used for segmentation will allow many surgeons to use segmentation of the vertebrae for diagnosis and even for preoperative simulation planning.

• 대한치과교정학회지
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• 제35권6호
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• pp.409-419
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• 2005

최근 들어 3차원 전산화 단층 촬영(CT, Computed Tomography) 영상을 이용한 진단기법의 개발을 위한 연구가 활발히 진행되고 있으며 여러 분야에서 3차원적인 두개악안면 분석의 필요성이 증대되고 있다. 특히 교정 치료나 악교정 수술 후의 결과에 있어서 안면 연조직의 분석은 필수적이라 할 것이다. 본 연구에서는 정상교합을 가진 성인 남자 12명, 성인 여자 11명의 CT 영상을 촬영하여 개인용 컴퓨터 상에서 V works 4.0 프로그램(Cybermed Inc., Seoul, Korea)으로 3차원 CT 연조직 영상을 재구성한 후에 soft tissue Nasion을 기준 원점으로 하는 3차원 좌표평면의 좌표계를 설정하여 정중선상의 soft tissue Nasion. Pronasale, Subnasale, Upper lip center, Lower lip center, soft tissue B. soft tissue Pogonion. soft tissue Menton 등 8개의 계측점과 양측성인 Eudocanthion, Alare lateralis, Cheilion, soft tissue Gonion, Tragus. Zygomatic point등 총 20개의 재현 가능한 안면 연조직의 계측점을 지정하였으며 V surgery 프로그램(Cybermed Inc., Seoul Korea)을 이용하여 이들 계측점의 3차원적인 좌표와 기준 원점으로부터 각 계측점까지의 Net (${\delta}=\sqrt{{X^2}+{Y^2}+{Z^2}}$) 값의 평균과 표준편차를 구하였다. 안면 연조직 분석의 3차원적인 이해를 돕기 위해 주요 계측점 간의 거리 계측을 시행하였고, 그 결과 Na'-Sn과 En (Rt)-En(Lt)를 제외한 대부분의 계측값에서 남녀간의 유의한 차이가 있었으며, 2차원적인 두부 방사선 규격사진이나 안면 사진으로는 정확한 계측이 어려웠던 Na'-Zy, Na'-Ch, Na'-Go'(facial depth) 등의 정상치도 구하였다. 이상의 자료는 부정교합 환자와 악안면 기형 환자의 3차원적인 진단 및 치료 계획에 참고자료로 사용될 수 있을 것이다.

• 대한방사선기술학회지:방사선기술과학
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• 제38권4호
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• pp.421-427
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• 2015

본 연구에서는 3차원(dimension, D) 프린터로 자체 제작한 팬톰을 이용하여 관전압과 관전류량 변화 중심으로 균일한 조직의 물리적 영역 크기 변화에 의한 관심영역(region of interest, ROI)와 설정치 영역 크기 변화에 의한 ROI 내에서의 하운스필드(hounsfield units, HU)의 변화를 알아보고자 하였다. 본 실험에서는 단면영상과 HU를 획득하기 위해 4-다중 검출기 전산화단층영상장비를 이용하였다. 팬톰 제작은 용융적층조형술(fused deposition modeling, FDM) 프린팅 방식의 3D 프린터 기기를 사용하였다. 팬톰의 구조는 $160{\times}160{\times}50mm$의 원통형으로 33 mm, 24 mm, 19 mm, 16 mm, 9 mm 크기의 원형 구멍을 대칭되도록 두 쌍으로 설계하였다. 구멍에는 증류수를 혼합한 조영제를 충전하였다. X선의 관전압과 관전류량는 각각 90 kVp, 120 kVp, 140 kVp 그리고 50 mAs, 100 mAs, 150 mAs로 변화시켜 단면영상을 획득하였다. 획득된 영상의 ROI 내 HU 측정은 image J 프로그램를 이용하였다. 그 결과, 관전류량보다는 관전압이 HU에 영향을 주고 있음을 확인하였다. 그리고 균일한 밀도를 갖는 물질이라도 물리적 영역 크기가 작아질수록 HU는 감소하였으며 ROI 설정 영역 크기가 작아질수록 HU는 증가하여 HU가 변화한다는 것을 확인할 수 있었다. 따라서 5 HU 이내의 노이즈 수준에서 ROI를 최대한 크게 설정하는 것이 물리적 영역 크기와 ROI 설정 영역 크기에 의한 변이를 최소화시킬 수 있는 방법이라고 판단된다.

• Clinics in Shoulder and Elbow
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• 제21권3호
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• pp.151-157
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• 2018

Background: Nonunion of lateral humeral condyle fracture causes cubitus valgus deformity. Although corrective osteotomy or osteosynthesis can be considered, there are controversies regarding its treatment. To evaluate elbow joint biomechanics in non-united lateral humeral condyle fractures, we analyzed the motion of elbow joint and pseudo-joint via in vivo three-dimensional (3D) kinematics, using 3D images obtained by computed tomography (CT) scan. Methods: Eight non-united lateral humeral condyle fractures with cubitus valgus and 8 normal elbows were evaluated in this study. CT scan was performed at 3 different elbow positions (full flexion, $90^{\circ}$ flexion and full extension). With bone surface model, 3D elbow motion was reconstructed. We calculated the axis of rotation in both the normal and non-united joints, as well as the rotational movement of the ulno-humeral joint and pseudo-joint of non-united lateral condyle in 3D space from full extension to full flexion. Results: Ulno-humeral joint moved to the varus on the coronal plane during flexion, $25.45^{\circ}$ in the non-united cubitus valgus group and $-2.03^{\circ}$ in normal group, with statistically significant difference. Moreover, it moved to rotate externally on the axial plane $-26.75^{\circ}$ in the non-united cubitus valgus group and $-3.09^{\circ}$ in the normal group, with statistical significance. Movement of the pseudo-joint of fragment of lateral condyle showed irregular pattern. Conclusions: The non-united cubitus valgus group moved to the varus with external rotation during elbow flexion. The pseudo-joint showed a diverse and irregular motion. In vivo 3D motion analysis for the non-united cubitus valgus could be helpful to evaluate its kinematics.

• Radiation Oncology Journal
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• 제28권3호
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• pp.177-183
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• 2010

목 적: 유방암 치료를 위한 방사선치료계획에 전산화단층촬영을 이용한 모의치료가 널리 이용되고 있다. 이는 환자 개개인의 해부학적 특징에 기반하여 종양 표적과 정상 조직을 정의할 수 있다. 본 연구는 일반적으로 유방 크기가 작은 한국인 유방암 환자에서 적용하는 방사선치료계획 방법에 따라 치료용적 및 치료범위에 차이가 있는지를 알아보기 위해 시행하였다. 대상 및 방법: 2008년 11월부터 2009년 1월까지 조기유방암으로 유방보존술을 시행 받은 25명의 환자를 대상으로 통상적인 접면조사의 이차원치료 계획과 전산화단층촬영을 기반으로 한 삼차원치료계획을 시행하였다. 이차원 치료계획에서 방사선조사영역의 경계는 유방실질을 촉지하여 결정하였고 위쪽으로는 쇄골의 바로 아래, 내측은 몸의 정중선, 외측은 중심 액와선 그리고 아래쪽은 유방밑주름에서 2 cm 아래에 표시하였다. 삼차원치료계획에서 임상표적체적은 모든 유선 조직을 포함하였고 계획용 표적체적은 임상표적체적에서 피부 쪽을 제외한 모든 방향으로 1 cm의 여유를 두어 결정하였다. 이차원과 삼차원치료계획 간의 조사영역의 경계 차이 및 동등조사영역의 차이를 확인하고 신체질량지수, 폐경 여부 및 유방크기의 관련성을 평가하였다. 그리고 선량분포로 지정한 유방조사량과 삼차원 선량분포에 기반하여 측정된 조사된 폐용적과 심장용적을 평가하였다. 결 과: 2명의 환자를 제외하고 계획용표적체적(PTV)은 삼차원치료계획이 이차원치료계획보다 모든 방향에서 표시한 방사선조사영역을 감소시켰고 위쪽 경계에서 그 차이값이 가장 컸다. 동등조사영역크기는 한 명을 제외하고 삼차원치료계획에서 이차원치료계획에서보다 작았으며(평균 0.9 cm), 신체질량지수, 폐경 여부 및 유방크기(브래지어 사이즈)와의 관련성은 보이지 않았다. 조사된 폐용적은 삼차원치료계획에서 유의하게 감소하였고, 심장용적 또한 감소하였지만 통계적으로 유의한 차이는 보이지 않았다. 결 론: 통상적인 치료계획과 비교하여 전산화단층촬영을 기반으로 한 삼차원치료계획이 작은 유방을 가진 환자에서 방사선조사영역 및 손상위험장기의 조사량을 줄이면서 수술 후 변화를 포함하여 더 정확한 종양치료가 가능할 수 있음을 보여주었다. 그러나 앞으로 임상표적체적의 정의에 대한 추가적인 연구 및 일반적인 합의가 필요하다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제40권
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• pp.30.1-30.6
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• 2018

Background: The purpose of the present study was to investigate the differences in the position and shape of the anterior loop of the inferior alveolar nerve (ALIAN) in relation to the growth pattern of the mandibular functional subunit. Methods: The study was conducted on 56 patients among those who had undergone orthognathic surgery at the Gangnam Severance Hospital between January 2010 and December 2015. Preoperative computerized tomography (CT) images were analyzed using the Simplant OMS software (ver.14.0 Materialise Medical, Leuven, Belgium). The anterior and inferior lengths of ALIAN (dAnt and dInf) and each length of the mandibular functional subunits were measured. The relationship between dAnt, dInf, and the growth pattern of the mandibular subunits was analyzed. Results: The length of the anterior portion of ALIAN (dAnt) reached 3.34 ± 1.59 mm in prognathism and 1.00 ± 0.97 mm in retrognathism. The length of the inferior portion of ALIAN (dInf) reached 6.81 ± 1.33 mm in prognathism and 5.56 ± 1.34 mm in retrognathism. The analysis of Pearson's correlation coefficiency on all samples showed that the lengths of functional subunits were positively correlated with the loop depth. The length of the symphysis area in prognathic patients was positively correlated with the anterior loop depth (p = 0.005). Conclusions: Both the anterior and inferior length of ALIAN are longer in prognathic patients. Especially, it seems to be associated with the growth of the symphysis area.