• The Korean Journal of Medicine
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• 제93권6호
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• pp.575-581
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• 2018

저자들은 최초 복부 CT 소견상 후복막강섬유화증으로 오인되었으나 적극적인 조직 검사를 통하여 후복막강에만 국한된 원발 부위 불명 전이암으로 진단된 증례를 경험하였다. 최근 후복막강섬유화증의 진단에 있어서 PET-CT 등 영상 검사가 기술적으로 많은 발전을 이루었지만 후복막강섬유화증의 진단시 악성종양의 배제는 필수적이기 때문에 후복막강섬유화증의 확진은 반드시 조직학적인 검사에 기초하여 이루어져야 함을 강조하는 바이다.

• 대한임베디드공학회논문지
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• 제18권6호
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• pp.267-275
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• 2023

This paper presents the development of specialized software for annotating volume-of-interest on ¹⁸F-FDG PET/CT images with the goal of facilitating the studies and diagnosis of head and neck cancer (HNC). To achieve an efficient annotation process, we employed the SE-Norm-Residual Layer-based U-Net model. This model exhibited outstanding proficiency to segment cancerous regions within ¹⁸F-FDG PET/CT scans of HNC cases. Manual annotation function was also integrated, allowing researchers and clinicians to validate and refine annotations based on dataset characteristics. Workspace has a display with fusion of both PET and CT images, providing enhance user convenience through simultaneous visualization. The performance of deeplearning model was validated using a Hecktor 2021 dataset, and subsequently developed semi-automatic annotation functionalities. We began by performing image preprocessing including resampling, normalization, and co-registration, followed by an evaluation of the deep learning model performance. This model was integrated into the software, serving as an initial automatic segmentation step. Users can manually refine pre-segmented regions to correct false positives and false negatives. Annotation images are subsequently saved along with their corresponding ¹⁸F-FDG PET/CT fusion images, enabling their application across various domains. In this study, we developed a semi-automatic annotation software designed for efficiently generating annotated lesion images, with applications in HNC research and diagnosis. The findings indicated that this software surpasses conventional tools, particularly in the context of HNC-specific annotation with ¹⁸F-FDG PET/CT data. Consequently, developed software offers a robust solution for producing annotated datasets, driving advances in the studies and diagnosis of HNC.

• Korean Journal of Radiology
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• 제21권4호
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• pp.494-500
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• 2020

Objective: This study presents a preliminary report on the chest radiographic and computed tomography (CT) findings of the 2019 novel coronavirus disease (COVID-19) pneumonia in Korea. Materials and Methods: As part of a multi-institutional collaboration coordinated by the Korean Society of Thoracic Radiology, we collected nine patients with COVID-19 infections who had undergone chest radiography and CT scans. We analyzed the radiographic and CT findings of COVID-19 pneumonia at baseline. Fisher's exact test was used to compare CT findings depending on the shape of pulmonary lesions. Results: Three of the nine patients (33.3%) had parenchymal abnormalities detected by chest radiography, and most of the abnormalities were peripheral consolidations. Chest CT images showed bilateral involvement in eight of the nine patients, and a unilobar reversed halo sign in the other patient. In total, 77 pulmonary lesions were found, including patchy lesions (39%), large confluent lesions (13%), and small nodular lesions (48%). The peripheral and posterior lung fields were involved in 78% and 67% of the lesions, respectively. The lesions were typically ill-defined and were composed of mixed ground-glass opacities and consolidation or pure ground-glass opacities. Patchy to confluent lesions were primarily distributed in the lower lobes (p = 0.040) and along the pleura (p < 0.001), whereas nodular lesions were primarily distributed along the bronchovascular bundles (p = 0.006). Conclusion: COVID-19 pneumonia in Korea primarily manifested as pure to mixed ground-glass opacities with a patchy to confluent or nodular shape in the bilateral peripheral posterior lungs. A considerable proportion of patients with COVID-19 pneumonia had normal chest radiographs.

• 한국산학기술학회논문지
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• 제18권7호
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• pp.84-91
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• 2017

본 연구는 컴퓨터 단층촬영 영상에서 제거할 수 없는 의료용 고밀도 물질을 Somatom Definition Flash(Siemens, Enlarge, Germany.)와 GE 64-MDCT (Discovery 750 HD, GE HEALTHCARE, Milwaukee, USA.)스캔 후 획득한 팬텀영상 데이터와 이미 촬영된 Raw 데이터영상을 이용하여 IMAR 알고리즘과 MAR 알고리즘 적용 및 재구성한 후 CT 재구성영상의 CT Number 변화율을 정량적으로 분석하였다. 그 결과 팬텀영상의 모든 의료용 고밀도 물질은 IMAR 알고리즘과 MAR 알고리즘 적용 시 CT Number의 변화와 영상의 차이가 있는 것으로 나타났지만(p<0.05). Stainless Steel 재질은 Black streak artifact에서 MAR 또는 IMAR 알고리즘 적용 시 재구성 영상의 변화와 CT Number의 변화차이가 없는 것으로 분석되었다(p>0.05). 또한 이미 촬영된 Raw 데이터영상 분석결과 IMAR 알고리즘 적용 시 적용 전에 비하여 영상 CT Number 변화가 있어, IMAR 알고리즘 적용은 Attenuation deviation에 영향을 미치는 것을 알 수 있었다. 이 결과를 바탕으로 향후 Implant시술 후 추적 CT검사 시 수술부위 및 주변조직의 상태를 관찰하는데 유용할 것으로 사료된다.

• 한국정보전자통신기술학회논문지
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• 제6권1호
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• pp.37-44
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• 2013

본 논문에서는 voxel classification을 이용한 폐 결절 자동 검출 시스템을 제안한다. 제안하는 폐 영상 분석 방법은 크게 세 단계로 구성된다. 첫 번째 단계에서는 분석 대상 폐 영역을 분할한다. 그리고 두 번째 단계는 분할된 폐 영역 내에서 폐 구조물을 분할한다. 마지막으로 두 번째 과정에서 분할된 폐결절후보와 폐혈관 voxel을 대상으로 log-polar sampling을 이용한 특징 벡터를 만들고, 특징벡터를 입력 값으로 하여 support vector machine classifier를 이용하여 분석대상 voxel을 폐 결절 voxel과 비결절 voxel로 구분하여 폐 결절을 검출한다.

• 한국정보전자통신기술학회논문지
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• 제5권1호
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• pp.13-19
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• 2012

본 논문에서는 계층적 삼차원 블록 영상분석을 이용한 폐결절 자동 검출 방법을 제안한다. 제안하는 블록 기반 폐 영상 분석 방법은 크게 두 부분으로 나눌 수 있다. 첫 번째는 블록을 분할하고 분석하고자 하는 대상 블록을 선택하는 과정이며 두 번째는 선택된 분석 대상 블록을 분석하는 과정이다. 첫 번째 과정을 통하여 선택된 분석대상 블록들은 다음 단계인 분석과정을 통해 결절과 비결절로 분리될 수 있다. 분석대상 블록의 중심에 있는 object에서 분석을 위한 형태 특징을 추출 하고, 추출된 형태 특징 값을 Support Vector Machine을 이용하여 결절과 비 결절로 분리한다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권6호
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• pp.2759-2764
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• 2014

Aim: This study aims to investigate the manifestation of CT, MRI and dynamic enhanced scans for primary hepatic neuroendocrine cell carcinoma. Methods: CT or MRI arterial and venous phase scan images of 19 cases of pathologically confirmed PHNEC were retrospectively analyzed. Results: 14 cases (73.68%) with single lesion, 5 cases (26.3%) with multiple lesions, with an average diameter of 13.2 cm. Some 12 cases (63.16%) showed inhomogeneous enhancement, seven cases (36.8%) showed homogeneous enhancement, 13 cases (68.4%) demonstrated significant enhancement in the arterial phase, 13 cases (68.4%) had significantly enhanced portal venous phase including 7 cases (36.8 %) with portal venous phase density or signal above the arterial phase and 5 cases (26.3%) with the portal vein density or signal below the arterial phase. Seven cases (36.8%) had continued strengthened separate shadows in the center of the lesion. Thrombosis were not seen in portal veins. Conclusion: CT and MRI images of liver cell neuroendocrine carcinoma have certain characteristics that can provide valuable information for diagnosis and differential diagnosis.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제33권6호
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• pp.467-477
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• 2011

Purpose: The objective of this study was to examine the affected period and the amount of bone formation during osteogenesis of intramembranous bone using low-intensity pulsed ultrasound (LPUS) $in$ $vivo$. Methods: Xeno-bone (Bio-oss) and autogenous bone were grafted bilaterally into mini-pig mandibles. The left mandible served as the control and the other mandible was treated with 3 MHz, 160 mW (output, 0.8 mW) ultrasound stimulation for 7 days 15 minutes per day. The mini-pigs were sacrificed at 1, 2, 4, and 8 weeks, and micro computed tomography (${\mu}CT$), a microscopic examination, and a statistical analysis were performed on the specimens. Results: Based on a computerized image analysis of the ${\mu}CT$ scans, the experimental group had an average 150% more new bone formation than that in the control group. The effect of LPUS continued during the post operative 2 weeks. The histomorphological microscopic examination showed similar results. Conclusion: Our results suggest the LPUS had an effect on early intramembranous bone formation in vivo.

• Asian Pacific Journal of Cancer Prevention
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• 제16권17호
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• pp.7897-7903
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• 2015

Background: To explored the value of 3D C-arm CT (CACT) guidance system in performing radiofrequency ablation (RFA) following transarterial chemoembolizationon (TACE) for hepatocellular carcinomas. Materials and Methods: RFA of hepatocellular carcinomas (HCC) were performed on 15 patients (21 lesions) with the assistance of CACT guidance system. Technical success, procedure time, complications and patient radiation exposure were investigated. The puncture performance level was evaluated on a five-point scale (5-1: excellent-poor). Complete ablation rate was evaluated after two months follow-up using enhanced CT scans. Results: The technical success rate of RFA procedure under CACT navigation system was 100 %. Mean total procedure time was $24.24{\pm}6.53min$, resulting in a mean effective exposure dose of $15.4{\pm}5.1mSv$. The mean puncture performance level rated for CACT guided RFA procedure was $4.87{\pm}0.35$. Complete ablation (CA) was achieved in 20 (95.2%) of the treated 21 tumors after the first RFA session. None of patients developed intra-procedural complications. Conclusions: 3D CACT guidance system enables reliable and efficient needle positioning by providing real-time intraoperative guidance for performing RFA on HCCs.

• 한국응급구조학회지
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• 제24권2호
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• pp.99-109
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• 2020

Purpose: Alcohol intoxication is frequently observed in patients with brain hemorrhage. The purpose of this study was to determine whether intoxication affects the Korean Triage and Acuity Stage (KTAS) level and the emergency medical process in emergency departments. Methods: This study was a retrospective observational study enrolled 253 brain hemorrhage patients (47 of those intoxicated) who visited the emergency medical center on public EMS ambulance from January. 1, 2017 to April, 30, 2019. Data were collected through the electronic medical record (EMR). KTAS level and time to computerized tomography (CT) were compared to evaluate whether inebriation affects care and examination processes. All data were analyzed using SPSS program. Results: Of the 47 patients intoxicated patients, 85.1% were male, and 74.5% accompanied by trauma. Initial KTAS level showed significant differences (77.2%; p=.000) when the level 3,4 was not drunk. The average time taken from triage to CT scans showed a significant difference of 24.81±23.72 (min) when the drunken state was not 58.38±56.54 (min)(p=.000). Conclusion: In patients with brain hemorrhage admitted to ED from public EMS, undertriage and delay after initial assessment were detected in inebriated patients. Careful initial evaluation and prompt medical response should be considered for patients transported by EMS.