• Archives of Plastic Surgery
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• 제51권1호
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• pp.52-61
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• 2024

Background Although prepectoral implant-based breast reconstruction has recently gained popularity, dual-plane reconstruction is still a better option for patients with poor-quality mastectomy skin flaps. However, shoulder morbidity is aggravated by subpectoral reconstruction, especially in irradiated patients. This study aimed to demonstrate shoulder exercise improvement in subpectoral reconstruction by delayed prepectoral conversion with an acellular dermal matrix (ADM) inlay graft technique at the time of expander-to-implant exchange after irradiation. Methods Patients with breast cancer treated for expander-to-implant exchange after subpectoral expander insertion and subsequent radiotherapy between January 2021 and June 2022 were enrolled. An ADM inlay graft was inserted between the pectoralis major muscle and the previously inserted ADM. The ADM was sutured partially overlapping the pectoralis muscle from the medial side with the transition part, to the muscle border at the lateral side. Perioperative shoulder joint active range-of-motion (ROM) for forward flexion, abduction, and external rotation was also evaluated. Results A total of 35 patients were enrolled in the study. Active shoulder ROM significantly improved from 163 degrees preoperatively to 176 degrees postoperatively in forward flexion, 153 to 175 degrees in abduction, and 69 to 84 degrees in external rotation. There was no difference in patient satisfaction regarding the final outcome between the conventional prepectoral reconstruction group and the study group. Conclusion Shoulder exercises in irradiated patients who underwent subpectoral reconstruction were improved by delayed prepectoral conversion using an ADM inlay graft. It is recommended that subpectoral reconstruction not be ruled out due to concerns regarding muscle contracture and shoulder morbidity in radiation-planned patients with poor mastectomy skin flaps.

• Korean Journal of Radiology
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• 제20권4호
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• pp.558-568
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• 2019

Objective: To evaluate whether computed tomography (CT) reconstruction algorithms affect the CT texture features of the liver parenchyma. Materials and Methods: This retrospective study comprised 58 patients (normal liver, n = 34; chronic liver disease [CLD], n = 24) who underwent liver CT scans using a single CT scanner. All CT images were reconstructed using filtered back projection (FBP), hybrid iterative reconstruction (IR) (iDOSE⁴), and model-based IR (IMR). On arterial phase (AP) and portal venous phase (PVP) CT imaging, quantitative texture analysis of the liver parenchyma using a single-slice region of interest was performed at the level of the hepatic hilum using a filtration-histogram statistic-based method with different filter values. Texture features were compared among the three reconstruction methods and between normal livers and those from CLD patients. Additionally, we evaluated the inter- and intra-observer reliability of the CT texture analysis by calculating intraclass correlation coefficients (ICCs). Results: IR techniques affect various CT texture features of the liver parenchyma. In particular, model-based IR frequently showed significant differences compared to FBP or hybrid IR on both AP and PVP CT imaging. Significant variation in entropy was observed between the three reconstruction algorithms on PVP imaging (p < 0.05). Comparison between normal livers and those from CLD patients revealed that AP images depend more strongly on the reconstruction method used than PVP images. For both inter- and intra-observer reliability, ICCs were acceptable (> 0.75) for CT imaging without filtration. Conclusion: CT texture features of the liver parenchyma evaluated using the filtration-histogram method were significantly affected by the CT reconstruction algorithm used.

• 한국산학기술학회논문지
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• 제14권7호
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• pp.3460-3467
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• 2013

본 논문에서는 2차원 대지구조를 분석하기 위해 ERT(electrical resistance tomography) 방법을 사용하여 대지모델을 영상복원하는 방법들을 수치적인 실험방법들을 통해 비교분석한다. 영상복원을 위한 역산방법으로는 Gauss-Newton, TLS(truncated least squares), 그리고 SIRT(simultaneous iterative reconstruction technieque) 알고리즘들이 제시되고 대지저항을 측정하기 위한 전극법은 대표적인 웨너와 슐럼버거 측정방법을 사용한다. 컴퓨터 시뮬레이션을 통해 Gauss-Newton과 TLS 알고리즘이 대지모델의 2차원 영상복원에서 적합하다는 것을 보인다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.475-475
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• 2003

• 센서학회지
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• 제19권2호
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• pp.118-123
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• 2010

This paper proposes super-resolution reconstruction algorithm for image enhancement. Super-resolution reconstruction algorithms reconstruct a high-resolution image from multi-frame low-resolution images of a scene. Conventional super- resolution reconstruction algorithms are iterative back-projection(IBP), robust super-resolution(RS)method and standard Papoulis-Gerchberg(PG)method. However, traditional methods have some problems such as rotation and ringing. So, this paper proposes modified algorithm to improve the problem. Experimental results show that this proposed algorithm solve the problem. As a result, the proposed method showed an increase in the PSNR for traditional super-resolution reconstruction algorithms.

• Current Optics and Photonics
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• 제7권6호
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• pp.692-700
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• 2023

We present a method for improving the accuracy of the modal wavefront reconstruction in the radial shearing interferometers (RSIs). Our approach involves expanding the reduced radial terms of Zernike polynomials to high-order, which enables more precise reconstruction of the wavefront aberrations with high-spatial frequency. We expanded the reduced polynomials up to infinite order with symbolic variables of the radius, shearing amount, and transformation matrix elements. For the simulation of the modal wavefront reconstruction, we generated a target wavefront subsequently, magnified and measured wavefronts were generated. To validate the effectiveness of the high-order Zernike polynomials, we applied both low- and high-order polynomials to the wavefront reconstruction process. Consequently, the peak-to-valley (PV) and RMS errors notably decreased with values of 0.011λ and 0.001λ, respectively, as the order of the radial Zernike polynomial increased.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제29권5호
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• pp.429-438
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• 2007

Transport distraction osteogenesis has been introduced recently to correct skeletal malformations and discrepancies in the maxillofacial area. To reconstruct 3-dimensitonal mandibular shape, this transport distraction can be considered with the use of reconstruction plate. A 23-years-old male having unilateral mandibular body and angle defects, who had been operated of partial mandibular resection due to unicystic ameloblastoma, was treated by transport distraction procedures with ThreadLock transport $distractor^{(R)}$ (KLS Martin Co., Germany) through the rail of reconstruction plate (Osteomed Co., USA). After being distracted 35 mm defect from mandibular angle to body, and consolidated for 16 weeks, allogenic bone graft on docking site was performed with removal of transgingival pin. For more than 13 weeks follow up period after consolidation period, gradual increase of radiopacity in the radiographic examination was shown, and the curved mandibular continuity according to the reconstruction plate was made firmly. These transport distraction osteogenesis in the mandible was able to be considered as the good and minimally invasive technique for the reconstruction of mandibular discontinuity. Young patient was also very satisfactory for these results.

• 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.

• 대한두경부종양학회지
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• 제35권1호
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• pp.21-23
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• 2019

Recent studies have reported on the reconstruction of oral mucosal defects using acellular dermal matrix (ADM). This case report describes the reconstruction of a soft-palate mucosal defect using ADM. A 43-year-old man developed a $2.5cm{\times}3cm$ soft-palate mucosal defect after the removal of a lump on the soft palate andreconstructed the defect using ADM without further complications. Reconstruction of the soft palate with ADM could be more convenient than traditional methods including primary closure, skin graft, and local or free flap without complications.

• 대한두개안면성형외과학회지
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• 제22권2호
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• pp.71-77
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• 2021

Hypopharyngeal reconstruction is a surgically challenging procedure, and postoperative management is important due to a high rate of complications following surgery. In particular, stricture and fistula formation is the most common long-term postoperative complication. Through systematic review and meta-analysis of 21 studies, a significant radiation effect of stricture and fistula formation was found in patients who underwent hypopharyngeal reconstruction. The perioperative radiation must be seen as a critical factor for stricture and fistula formation in hypopharyngeal reconstruction.