• 제목/요약/키워드: statistical reconstruction

검색결과 207건 처리시간 0.024초

The Medial Sural Artery Perforator Flap versus Other Free Flaps in Head and Neck Reconstruction: A Systematic Review

  • Yasser Al Omran;Ellie Evans;Chloe Jordan;Tiffanie-Marie Borg;Samar AlOmran;Sarvnaz Sepehripour;Mohammed Ali Akhavani
    • Archives of Plastic Surgery
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    • 제50권3호
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    • pp.264-273
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    • 2023
  • The medial sural artery perforator (MSAP) flap is a versatile fasciocutaneous flap, and yet is less commonly utilized than other free flaps in microvascular reconstructions of the head and neck. The aim is to conduct a high-quality Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA)- and Assessment of Multiple Systematic Reviews 2 (AMSTAR 2)-compliant systematic review comparing the use of the MSAP flap to other microvascular free flaps in the head and neck. Medline, Embase, and Web of Science databases were searched to identify all original comparative studies comparing patients undergoing head and neck reconstruction with an MSAP flap to the radial forearm free flap (RFFF) or anterolateral thigh (ALT) flap from inception to February 2021. Outcome studied were the recipient-site and donor-site morbidities as well as speech and swallow function. A total of 473 articles were identified from title and abstract review. Four studies met the inclusion criteria. Compared with the RFFF and the ALT flaps, the MSAP flap had more recipient-site complications (6.0 vs 10.4%) but less donor-site complications (20.2 vs 7.8%). The MSAP flap demonstrated better overall donor-site appearance and function than the RFFF and ALT flaps (p = 0.0006) but no statistical difference in speech and swallowing function following reconstruction (p = 0.28). Although higher quality studies reviewing the use of the MSAP flap to other free flaps are needed, the MSAP flap provides a viable and effective reconstructive option and should be strongly considered for reconstruction of head and neck defects.

소아 흉부 CT 검사에서 재구성 기법에 따른 영상의 유용성 평가 (Evaluation of the usefulness of Images according to Reconstruction Techniques in Pediatric Chest CT)

  • 김구;곽종혁;이승재
    • 한국방사선학회논문지
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    • 제17권3호
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    • pp.285-295
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    • 2023
  • 기술의 발전으로 CT 검사에 있어 환자가 받는 피폭선량을 줄이기 위한 노력은 새로운 재구성 기법 개발과 함께 계속 진행되고 있다. 최근에는 반복적 재구성 기법의 한계를 극복하기 위해 딥러닝 재구성 기법이 개발되었다. 본 연구는 소아 흉부 CT 영상에서 재구성 기법에 따른 영상의 유용성을 평가하였다. 환자 실험은 2021년 1월 2일부터 2022년 12월 31일까지 경상남도 P 병원에서 흉부 조영 CT 검사를 받은 소아 환자 중 85명을 대상으로 연구를 진행하였다. 팬텀 실험에 사용된 팬텀은 Pediatric Whole Body Phantom PBU-70이다. 검사 후 FBP, ASIR-V(50%), DLIR(TF-Medium,High)로 영상을 재구성했고, 동일한 크기의 ROI를 설정하여 HU값, SD값을 획득하여 SNR, CNR 값을 산출하여 영상을 평가하였다. 그 결과 DLIR의 TF-H가 모든 실험에서 ASIR-V(50%)와 TF-M에 비해 잡음 값이 가장 낮았으며, SNR과 CNR의 값이 가장 높았다. 소아 흉부 CT 검사에서 DLIR이 적용된 TF 영상이 ASiR-V 영상보다 잡음이 적었고, CNR과 SNR은 높은 것으로 나타났으며 DLIR이 적용되면 기존의 재구성법에 비해 영상의 질이 더 향상될 것으로 판단된다.

식도암의 임상적 고찰 (Clinical Evaluation of Esophageal Cancer)

  • 현명섭;임승균;정광진
    • Journal of Chest Surgery
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    • 제28권3호
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    • pp.280-286
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    • 1995
  • In our hospital we have seen 38 cases of esophageal cancer from June 1984 until June 1994. They composed of 34[89% men and 4[11% women, their age distributed from 35 to 74, mean age was 57.55 7.43. Their symptoms were varied, dysphagia[97% , pyrosis[58% , chest pain[31% , weight loss[31% , anemia[8% , vomiting[5% , and hoarseness[1% . Surgical treatment was done with esophagectomy and upper GI reconstruction 35 cases, and palliative gastrostomy was 3 cases. There was no operative mortality, and operative morbidity was 8 cases of anastomotic leakage, 5 cases of wound infection, 5 cases of pleural effusion, hoarseness, pneumothorax, and lung abscess. Pathologic lesion distribution: upper thoracic esophagus 6 cases[16% , middle thoracic esophagus 17 cases[45% , and lower thoracic esophagus 15 cases[39% . There was no statistical difference of transhiatal esophagectomy and transthoracic esophagectomy in complications and hospitalization period in this study but we proved the superiority of gastric upper GI reconstruction rather than colon upper GI reconstruction in anastomotic leakage and hospitalization period. Cumulative survival rate was 76.2% in 1 year survival, 33.9% in 3 year survival, 25.4% in 5 year survival, 12.7% in 10 year survival. There was no relationship with the time of dysphagia with survival in this study.

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차량 사고 분석에서 측정의 불확실성 (Uncertainty of Measurements in the Analysis of Vehicle Accidents)

  • 한인환;박승범
    • 대한교통학회지
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    • 제28권3호
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    • pp.119-130
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    • 2010
  • 교통사고의 재구성 해석은 도로와 사고흔적, 자동차 손상 등 다양한 자료들을 분석함으로서 이루어진다. 대부분의 자료들은 사고 해석에서 변수로 작용하며, 측정으로부터 구해지는 자료들은 조사자와 도구, 주어진 환경 등에 의해 측정 오차가 발생된다. 따라서 사고해석에서는 측정 오차에서 비롯되는 불확실성이 항상 존재한다. 본 연구는 불확실성이 존재할 가능성이 매우 높은 도로 기하구조와 타이어 흔적 등 길이와 마찰계수 등에 대해 반복 측정 실험을 함으로서 교통 사고해석에서의 불확실성을 정량화하였다. 또한 자동차 충돌 변형량의 사진 계측에 대한 불확실성에 대해서도 해석 결과를 제시하였다. 이러한 통계학적 분포들은 사고 재구성 불확실성을 추정하기 위해 입력 계수의 적절한 범위를 결정하는 것을 도울 수 있다.

Comparison of Costochondral Graft and Customized Total Joint Reconstruction for Treatments of Temporomandibular Joint Replacement

  • Lee, Woo-Young;Park, Young-Wook;Kim, Seong-Gon
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제36권4호
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    • pp.135-139
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    • 2014
  • Purpose: We review published research on temporomandibular joint (TMJ) total replacement that compares costochondral graft and customized total joint reconstruction (especially TMJ concepts), focusing on effectiveness. Methods: We searched PubMed databases, including prospective, retrospective, case-control or longitudinal studies and significant statistical analysis. In data analysis, we divided outcomes into 'Acceptable' or 'Non-acceptable'. Results: There were seven articles found dealing with costochondral graft and 180 patients. The majority of patients had satisfactory treatment outcomes (n=109, 61%). There were six articles including 275 patients using the alloplastic material TMJ concepts. Almost all patients had satisfactory treatment outcomes (n=261, 95%). Conclusion: Comparing customized total joint reconstruction with costochondral graft, use of TMJ concepts resulted in increased quality of life and fewer complications. In conclusion, we judged that alloplastic material such as TMJ concepts is more effective device in total joint replacement than costochondral graft.

웨이브렛 변환을 이용한 훼손된 신호의 복원에 관한 연구 (A Study on Reconstruction of Degraded Signal using Wavelet Transform)

  • 김남호;배상범;류지구
    • 융합신호처리학회논문지
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    • 제6권1호
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    • pp.33-38
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    • 2005
  • 데이터를 디지털화하거나 전송하는 과정에서 여러 가지 원인에 의해 열화가 발생하고 있으며, 이러한 열화의 주된 원인은 잡음이다. 따라서 잡음에 의해 훼손된 신호를 복원하기 위하여 웨이브렛을 이용한 방법들에 대한 연구가 활발히 진행되고 있다. 그리고 AWGN 환경에서 잡음을 제거하기 위한 가장 일반적인 연구 동향은 threshold에 기초한 방법들이다. 그러나 이러한 방법은 잡음에 대한 통계적인 특징만을 고려함에 따라 복원된 신호는 여전히 많은 잡음들을 포함한다. 따라서 본 논문에서는 웨이브렛 상세계수의 누적을 통한 새로운 신호 복원 방법을 제시하여, 신호의 edge 성분에 대한 복원과 잡음 제거 성능을 향상시켰다. 그리고 개선 효과의 판단 기준으로 SNR을 사용하였으며, 객관적인 판단을 위해 기존의 방법들과 비교하였다.

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컴퓨터를 이용한 의료 진단용 3차원 척추 제네릭 모델 (3D Generic Vertebra Model for Computer Aided Diagnosis)

  • 이주성;백승엽;이건우
    • 한국CDE학회논문집
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    • 제15권4호
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    • pp.297-305
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    • 2010
  • Medical image acquisition techniques such as CT and MRI have disadvantages in that the numerous time and efforts are needed. Furthermore, a great amount of radiation exposure is an inherent proberty of the CT imaging technique, a number of side-effects are expected from such method. To improve such conventional methods, a number of novel methods that can obtain 3D medical images from a few X-ray images, such as algebraic reconstruction technique (ART), have been developed. Such methods deform a generic model of the internal body part and fit them into the X-ray images to obtain the 3D model; the initial shape, therefore, affects the entire fitting process in a great deal. From this fact, we propose a novel method that can generate a 3D vertebraic generic model based on the statistical database of CT scans in this study. Moreover, we also discuss a method to generate patient-tailored generic model using the facts obtained from the statistical analysis. To do so, the mesh topologies of CT-scanned 3D vertebra models are modified to be identical to each other, and the database is constructed based on them. Furthermore, from the results of a statistical analysis on the database, the tendency of shape distribution is characterized, and the modeling parameters are extracted. By using these modeling parameters for generating the patient-tailored generic model, the computational speed and accuracy of ART can greatly be improved. Furthermore, although this study only includes an application to the C1 (Atlas) vertebra, the entire framework of our method can be applied to other body parts generally. Therefore, it is expected that the proposed method can benefit the various medical imaging applications.

설악산 지역의 Tree-ring 자료를 이용한 연 강수량 재생성 (Annual Precipitation Reconstruction Based on Tree-ring Data at Seorak)

  • 곽재원;한희찬;이민정;김형수;문장원
    • 한국물환경학회지
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    • 제31권1호
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    • pp.19-28
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    • 2015
  • The purpose of this research is reconstruction of annual precipitation based on Tree-ring series at Seorak mountain and examine its effectiveness. To do so we performed nonlinear time series characteristics test of Tree-ring series and reconstructed annual precipitation of Gangneung from 1687 to 1911 using Artificial neural network and Nonlinear autoregressive exogeneous input (NARX) model which reflects stochastic properties. As a result, Tree-ring series at Seorak Mountain shows nonlinear time series property and reconstructed annual precipitation series drawn from NARX is similar in statistical characteristics of observed annual time series.

Volumetric change of the latissimus dorsi muscle after postoperative chemotherapy and radiotherapy in immediate breast reconstruction with an extended latissimus dorsi musculocutaneous flap: final results from serial studies

  • Song, Kyeong Ho;Oh, Won Seok;Lee, Jae Woo;Kim, Min Wook;Jeong, Dae Kyun;Bae, Seong Hwan;Kim, Hyun Yul;Jung, Youn Joo;Choo, Ki Seok;Nam, Kyung Jin;Joo, Ji Hyeon;Yun, Mi Sook;Nam, Su Bong
    • Archives of Plastic Surgery
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    • 제48권6호
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    • pp.607-613
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    • 2021
  • Background Breast reconstruction using an extended latissimus dorsi (eLD) flap can supplement more volume than reconstruction using various local flaps after partial mastectomy, and it is a valuable surgical method since the reconstruction area is not limited. However, when performing reconstruction, the surgeon should consider latissimus dorsi (LD) volume reduction due to postoperative chemotherapy (POCTx) and postoperative radiotherapy (PORTx). To evaluate the effect of POCTx and PORTx on LD volume reduction, the effects of each therapy-both separately and jointly-need to be demonstrated. The present study quantified LD volume reduction in patients who underwent POCTx and PORTx after receiving breast-conserving surgery (BCS) with an eLD flap. Methods This study included 48 patients who received immediate breast reconstruction using an eLD flap from January 2013 to March 2017, had chest computed tomography (CT) 7-10 days after surgery and 10-14 months after radiotherapy completion, and were observed for more than 3 years postoperatively. One surgeon performed the breast reconstruction procedures, and measurements of breast volume were obtained from axial CT views, using a picture archiving and communication system. A P-value <0.05 was the threshold for statistical significance. Results The average volume reduction of LD at 10-14 months after completing POCTx and PORTx was 64.5% (range, 42.8%-81.4%) in comparison to the volume measured 7-10 days after surgery. This change was statistically significant (P<0.05). Conclusions Based on the findings of this study, when harvesting an eLD flap, surgeons should anticipate an average LD volume reduction of 64.5% if chemotherapy and radiotherapy are scheduled after BCS with an eLD flap.

저 선량 전산화단층촬영의 관전압과 적응식 통계적 반복 재구성법 적용에 따른 영상평가 및 피폭선량 (Image Evaluation and Exposure Dose with the Application of Tube Voltage and Adaptive Statistical Iterative Reconstruction of Low Dose Computed Tomography)

  • 문태준;김기정;이혜남
    • 대한방사선기술학회지:방사선기술과학
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    • 제40권2호
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    • pp.261-267
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    • 2017
  • 저 선량 흉부 전산화단층촬영(low dose computed tomography; LDCT)검사 시 기존의 검사방법인 필터보정역투영법인 FBP(filted back projection)와 적응식 통계적 반복 재구성법인 ASIR(adaptive statistical iterative reconstruction)의 적용 및 관전압 변화에 따른 영상의 화질과 피폭선량을 비교 평가해 보고자 하였다. 흉부 phantom을 이용하여 재구성방법에 따라 FBP와 ASIR적용(10%, 20%)을 하였고, 관전압(100kVp, 120kVp)에 변화를 주어 실험을 하였다. 화질평가를 위해 back-ground noise와 signal-noise ratio(SNR), contrast-noise ratio(CNR)를 구하였으며, 선량평가를 위해 CTDIvol과 DLP를 구하였다. 화질평가에 있어 kVp에 따른 ascending aorta(AA) SNR과 inpraspinatus muscle(IM) SNR은 AA SNR과 IM SNR은 유의한 차이가 있었다(p < 0.05). 선량평가에 있어 CTDIvol과 DLP는 유의한 차이가 있었으며(p < 0.05), CTDIvol은 120 kVp, FBP가 2.6 mGy, 120 kVp, 10%-ASIR가 2.38 mGy, 120kVp, 20%-ASIR가 2.17 mGy로 0.43 mGy 감소하였고, 100 kVp, FBP가 1.61 mGy, 100 kVp, 10%-ASIR가 1.48 mGy, 100 kVp, 20%-ASIR가 1.34 mGy로 0.27 mGy 감소하였다. 또한 DLP에서는 120 kVp, FBP가 $103.21mGy{\cdot}cm$, 120 kVp, 10%-ASIR가 $94.57mGy{\cdot}cm$, 120 kVp, 20%-ASIR가 $85.94mGy{\cdot}cm$$17.27mGy{\cdot}cm$(16.7%) 감소하였고, 100 kVp, FBP가 $63.87mGy{\cdot}cm$, 100 kVp, 10%-ASIR가 $58.54mGy{\cdot}cm$, 100 kVp, 20%-ASIR가 $53.25mGy{\cdot}cm$$10.62mGy{\cdot}cm$(16.7%)로 감소하였다. 재구성방법에 따른 FBP와 ASIR 10%, 20%에서는 화질의 변화 없이 선량을 줄일 수 있어 흉부 low dose CT검사 시 ASIR 20%적용하여 검사하는 것이 좋으며, 관전압 변화에 따른 120 kVp와 100 kVp에서는 선량은 크게 줄어들었지만, noise가 증가하여 화질이 떨어지는 것으로 나타났다.