• Maxillofacial Plastic and Reconstructive Surgery
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• 제41권
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• pp.14.1-14.10
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• 2019

Background: Condylar dislocation can arise as a complication in patients who required mandibular and/or condylar reconstruction and were operated on with fibula free flap (FFF) using surgical guides designed using simulation surgery. Surgeons should be aware of the complications in these present cases when planning and performing reconstructions as well as predicting prognoses. Cases presentation: Two cases showed condylar dislocation in mandibular reconstruction using a FFF fixed with a reconstruction plate. Three cases showed condylar dislocation in mandibular reconstruction using a fibula free flap fixed with a mini-plate. Conclusion: Despite the lack of clinical symptoms in these cases following mandibular reconstruction using an FFF, the mandibular condyle was severely displaced away from the glenoid fossa. A surgeon must have sufficient time to consider the use of a long flap with thickness similar to that of the mandible, ways to minimize span and bending, and methods of fixation. The patient, moreover, should be educated on condylar dislocation. Customized CAD/CAM-prototyped temporomandibular condyle-connected plates may be a good alternative even if virtual simulation surgery is to be performed before surgery. These considerations may help reduce the incidence of complications after mandibular reconstruction.

• Archives of Plastic Surgery
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• 제43권5호
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• pp.470-473
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• 2016

Nipple-areolar complex (NAC) reconstruction is the final step in the long journey of breast reconstruction for mastectomy patients. Successful NAC reconstruction depends on the use of appropriate surgical techniques that are simple and reliable. To date, numerous techniques have been used for nipple reconstruction, including contralateral nipple sharing and various local flaps. Recently, it has been common to utilize local flaps. However, the most common nipple reconstruction problem encountered with local flaps is the loss of nipple projection; there can be approximately 50% projection loss in reconstructed nipples over long-term follow-up. Several factors might contribute to nipple projection loss, and we tried to overcome these factors by performing nipple reconstructions using a boomerang flap technique, which is a modified C-V flap that utilizes the previous mastectomy scar to maintain long-term nipple projection.

• 비파괴검사학회지
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• 제22권5호
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• pp.545-556
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• 2002

Algebraic reconstruction technique (ART)과 multiplicative algebraic reconstruction technique (MART)이라는 토모그래피 방법을 이용하여 2상유동에서 기포의 거동을 배침투적으로 분석하였다. 먼저, 컴퓨터 합성 영상장으로 환상유통과 기포유동을 제작하여 2차원 단면의 재건을 시도하였다. 2상유동의 보다 정확한 결과들을 얻기 위하여 두가지 토모그래피 방법이 비교되었다. 그리고, 2상유동에서 기포의 거동을 3차원으로 분석하기 위하여 2개와 3개의 기포가 존재하는 3차원 합성 영상장으로부터 2차원 단면에서 보다 정확한 결과를 보인 MART 재건법에 의해서 밀도 분포 해석을 수행하였다.

• 천문학회지
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• 제49권4호
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• pp.157-162
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• 2016

High resolution reconstruction technology is developed to help enhance the spatial resolution of observational images for ground-based solar telescopes, such as speckle masking. Near real-time reconstruction performance is achieved on a high performance cluster using the Message Passing Interface (MPI). However, much time is spent in reconstructing solar subimages in such a speckle reconstruction. We design and implement a novel parallel method for speckle masking reconstruction of solar subimage on a shared memory machine using the OpenMP. Real tests are performed to verify the correctness of our codes. We present the details of several parallel reconstruction steps. The parallel implementation between various modules shows a great speed increase as compared to single thread serial implementation, and a speedup of about 2.5 is achieved in one subimage reconstruction. The timing result for reconstructing one subimage with 256×256 pixels shows a clear advantage with greater number of threads. This novel parallel method can be valuable in real-time reconstruction of solar images, especially after porting to a high performance cluster.

• 대한치과의사협회지
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• 제49권9호
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• pp.527-534
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• 2011

Microvascular reconstruction of maxillary composite defect after oncologic resection has improved both esthetic and functional aspect of quality of life of the cancer patients. However, a lot of patients had prior surgery with radiation and/or chemotherapy as a part of comprehensive cancer treatment. Sometimes it is nearly impossible to find out adequate recipient vessel for maxillary reconstruction with microvascular anastomosis. Therefore long pedicle of the flap is needed to use distant neck vessels located far from the reconstruction site such as ipsilateral transverse cervical artery or a branch of contralateral external carotid artery. For this reason, although we know the treatment of the choice is osteocutaneous flap, it is difficult to use this flap when we need long pedicle with complex three dimensional osseous defect. Vascular option for these vessel-depleted neck patients can be managed by a soft tissue reconstruction with long vascular pedicle and additional free non-vascularized flap that is rigidly fixed to remaining skeletal structures. For this reason, maxillofacial reconstruction by vascularized soft tissue flap with or without the secondary restoration of maxillary bone with non-vascularized iliac bone can be regarded as one of options for reconstruction of profound maxillofacial composite defect resulted from previous oncological resection with chemo-radiotherapy.

• Journal of International Society for Simulation Surgery
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• 제1권2호
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• pp.80-82
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• 2014

Purpose Microtia is congenital anomaly of external ear and the reconstruction method for the external ear of microtia patient was based on autogenous costal cartilage framework. The application of 3D printing technique in medical science has made more possibility of human tissue restoration, and we tried to apply this technique in auricular reconstruction field. Materials and Methods As for unilateral microtia patient, the contralateral side ear is normal and reconstructive surgeon tried to mimic it for reconstruction of affected ear. So, we obtained facial CT scan of microtia patient and made mirror image of normal side ear. Moreover, to make the 3D scaffold based on the mirror image of normal ear and to apply this scaffold for the auricular reconstruction surgery, we included auriculocephalic sulcus and anterior fixation part. Results We could successfully obtain mirror image of normal ear, auriculocephalic sulcus and anterior fixation part for 3D scaffold printing. Conclusions Using this CT image processing and 3D printing technique, we will be able to make the scaffold for auricular reconstruction of unilateral microtia patient, and perform auricular reconstruction in near future.

• 한국위성정보통신학회논문지
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• 제9권4호
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• pp.104-110
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• 2014

본 논문에서는 무인항공기인 방송용 멀티콥터를 이용한 Full-HD급 이상 화질의 이미지를 효율적으로 전송하기 위해 이미지 압축 센싱 기법을 적용하고, Sparse 신호의 효율적 복원을 위해 Turbo 알고리즘과 Markov chain Monte Carlo (MCMC) 알고리즘의 복원 성능을 모의실험을 통해 비교 분석하였다. 제안된 복원 기법은 압축 센싱에 기반하여 데이터 용량을 줄이고 빠르고 오류 없는 원신호 복원에 중점을 두었다. 다수의 이미지 파일로 모의실험을 진행한 결과 Loopy belief propagation(BP) 기반의 Turbo 복원 알고리즘이 Gibbs sampling기반 알고리즘을 수행하는 MCMC 알고리즘 보다 평균 복원 연산 시간, NMSE 값에서 우수하여 보다 효율적인 복원 방법으로 생각된다.

• Journal of Yeungnam Medical Science
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• 제23권1호
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• pp.1-9
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• 2006

Breast reconstruction provides dramatic improvement for patients with severe deformity. The reconstruction not only restores aesthetically acceptable breast for patients with mastectomy deformity but also recovers psychological trauma of 'losing feminity' after the cancer mastectomy. There are many options for breast reconstruction from simple prosthetic insertion to a flap operation using autologous abdominal tissue. The choice of operation method depends on the physical condition of the patient, smoking habits, and economic status. Among the many options, the method that uses the lower abdominal tissue is known as the TRAM (transverse rectus abdonimis myocutaneous) flap. Since the introduction of the TRAM flap in 1982 by Hartrampf, the art of breast reconstruction using lower abdominal tissue has been progressively refined to pedicle flap, muscle-sparinga TRAM flap, and recently there have been exciting and revolutionary changes associated with the adoption of the concept of perforator flap. This refined method of breast reconstruction utilizes lower abdominal tissue nourished by the deep inferior epigastric perforator (DIEP). With the DIEP free flap, almost all of the rectus muscle and anterior rectus sheath are preserved and the donor morbidity is minimized. Different from previous flap methods using lower abdominal tissue, DIEP free flap method preserves function of the rectus muscle completely. 1) Understanding the entire progression of breast reconstruction methods using lower abdominal tissue is necessary for plastic surgeons; the understanding of each step of the exciting progression and the review of the past history of the TRAM flap may provide insight for future development.

• 대한두경부종양학회지
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• 제35권1호
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• pp.1-11
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• 2019

In head and neck reconstruction, microsurgeons are faced with various demands, such as thin resurfacing, or three-dimensional reconstruction, and therefore, conventional flap as well as perforator flaps are all useful for the functional and aesthetic reconstruction successfully. Among perforator flaps, the pros and cons of anterolateral thigh perforator flap(ALTp) and thoracodorsal perforator flap(TAp) is compared and selected depending on the surgeon's preference, recipient site condition or patient status. Both flaps can be elevated in a chimeric pattern by combining different aspects of tissue components. Customized or tailored reconstruction as well as 3 dimensional reconstructions are all available with perforator flaps and it is useful in head and neck reconstruction. The most outstanding update in head and neck reconstruction is the perforator based island flap (PBIF) compared to conventional flaps. The conventional local flap has evolved on behalf of the perforator concept and its design becomes more flexible and freestyle with less limitations. Actually, random pattern flap is now a misnomer and most conventional local flaps turn into PBIFs. Finally we can say all conventional donor site becomes universal, depending on the surgeons' preference or idea. Moreover, there is no more "flap of choice" and postoperative results are quite variable by surgeons' ability. Operative procedures and plans are very flexible to freestyle flap. With all these advantages, surgeons should be armed with both conventional and perforator concepts for solving any defects or problems.

• 대한방사선기술학회지:방사선기술과학
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• 제42권2호
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• pp.119-130
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• 2019

Positron emission tomography (PET) is widely used imaging modality for effective and accurate functional testing and medical diagnosis using radioactive isotopes. However, PET has difficulties in acquiring images with high image quality due to constraints such as the amount of radioactive isotopes injected into the patient, the detection time, the characteristics of the detector, and the patient's motion. In order to overcome this problem, we have succeeded to improve the image quality by using the dynamic image reconstruction method based on singular value decomposition. However, there is still some question about the characteristics of the proposed technique. In this study, the characteristics of reconstruction method based on singular value decomposition was estimated over computational simulation. As a result, we confirmed that the singular value decomposition based reconstruction technique distinguishes the images well when the signal - to - noise ratio of the input image is more than 20 decibels and the feature vector angle is more than 60 degrees. In addition, the proposed methode to estimate the characteristics of reconstruction technique can be applied to other spatio-temporal feature based dynamic image reconstruction techniques. The deduced conclusion of this study can be useful guideline to apply medical image into SVD based dynamic image reconstruction technique to improve the accuracy of medical diagnosis.