• 전자공학회논문지CI
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• 제45권5호
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• pp.56-62
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• 2008

의사결정나무를 구성하여 강판튜브 비파괴평가에 사용하는 산업용 CR영상의 측정 패턴인식을 도모한다. 본래 비파괴평가는 기계학습기법에 의한 패턴식별과 그 분류에 적합한 분야이다. 의사결정나무의 속성들은 비파괴평가 테스트 절차로부터 취한다. 방사선조사 입사각, 경사도 및 거리 둥의 기하학적 특성들은 입력 영상 데이터 분석으로부터 추정한다. 이 요소들은 대상 입력을 의사결정나무에서 미리 정해진 분류에로 정확히 그리고 쉽게 분류가 이루어지도록 한다. 이 알고리즘은 비파괴평가 결과의 특성화를 간단히 하며 특성 결정을 간편하게 한다. 실험 결과는 제안한 알고리즘의 유용성을 보였다.

• Clinical and Experimental Pediatrics
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• 제58권5호
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• pp.190-193
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• 2015

Allergic bronchopulmonary aspergillosis (ABPA) is a hypersensitivity lung disease due to bronchial colonization of Aspergillus fumigatus that occurs in susceptible patients with asthma or cystic fibrosis. A 10-year-old girl was referred to the Department of Pediatric Pulmonology for persistent consolidations on chest radiography. Pulmonary consolidations were observed in the right upper and left lower lobes and were not resolved with a 4-week prescription of broad-spectrum antibiotics. The patient had a history of atopic dermatitis and allergic rhinitis but no history of asthma. She had no fever but produced thick and greenish sputum. Her breathing sounds were clear. On laboratory testing, her total blood eosinophil count was $1,412/mm^3$ and total serum IgE level was 2,200 kU/L. Aspergillus was isolated in the sputum culture. The A. fumigatus-specific IgE level was 15.4 kU/L, and the Aspergillus antibody test was also positive. A chest computed tomography scan demonstrated bronchial wall thickening and consolidation without bronchiectasis. An antifungal agent was added but resulted in no improvement of pulmonary consolidations after 3 weeks. Pulmonary function test was normal. Methacholine provocation test was performed, revealing bronchial hyperreactivity ($PC_{20}=5.31mg/mL$). Although the patient had no history of asthma or bronchiectasis, ABPA-seropositivity was suspected. Oral prednisolone (1 mg/kg/day) combined with antifungal therapy was started. Pulmonary consolidations began decreasing after 1 week of treatment and completely resolved after 1 month. This is the first observed and treated case of seropositive ABPA in Korean children without previously documented asthma.

• Tuberculosis and Respiratory Diseases
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• 제70권3호
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• pp.257-260
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• 2011

A 65-year-old woman was admitted due to poor oral intake and a dry cough over the previous 3 months. The physical examination was remarkable for bibasilar crackles, and plain chest radiography showed reticulation in both lower lung fields. A pulmonary function test demonstrated a restrictive pattern with a reduced diffusing capacity of the lung for carbon monoxide. High resolution computed tomography showed reticulation and honey-combing in both peripheral lung zones, which was consistent with usual interstitial pneumonia pattern. Her skin showed livedo reticularis. The erythrocyte sedimentation rate and C-reactive protein level were elevated, and hematuria was noted on urinary analysis. A serologic test for auto-antibodies showed seropositivity for Myeloperoxidase-Anti-neutrophil cytoplasmic antibody (MPO-ANCA). A kidney biopsy was performed and showed focal segmental glomerulosclerosis. She was diagnosed as having pulmonary fibrosis with microscopic polyangiitis (MPA) and treated with high dose steroids. Here we report a case of pulmonary fibrosis coexistent with microscopic polyangiitis.

• Restorative Dentistry and Endodontics
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• 제47권4호
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• pp.41.1-41.20
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• 2022

Objectives: This study compared the clinical and radiological outcomes of regenerative endodontic procedures (REPs) using blood clots (BCs), platelet-rich plasma (PRP), and platelet-rich fibrin (PRF) through intraoral periapical radiography (IOPAR) and cone-beam computed tomography (CBCT). Materials and Methods: Forty-five single-rooted necrotic teeth with periapical pathology were randomly allocated to receive BC, PRP, or PRF as an individual scaffold. Outcomes were evaluated in 35 teeth in 23 patients with a follow-up period of 12-24 months through qualitative IOPAR scoring and quantitative CBCT measurements. Healing of periapical lesions and in immature teeth, changes in the apical foramen diameter (AFD), root wall thickness (RWT), and root length (RL) were assessed. A p value less than 0.05 was considered to indicate statistical significance. Results: All teeth were asymptomatic except 1 in the PRP group. Periapical lesion healing was seen in all except 2 teeth in the BC group and 3 in the PRP group. Both IOPAR and CBCT revealed no significant differences in bone healing or changes in AFD, RWT, and RL among the 3 groups. A positive pulp sensibility response to the cold test was seen in 2 teeth in the BC group, but none to the electric pulp test. Intracanal calcification (ICC) was evident in more teeth in the BC group than in the PRP and PRF groups, and was also significantly higher in immature teeth. Conclusions: Our results revealed that BC, PRP, and PRF have similar potential as scaffolds in REPs, and ICC may be a concern for long-term outcomes.

• Imaging Science in Dentistry
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• 제44권1호
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• pp.53-60
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• 2014

Purpose: This study was performed to investigate the incidence and configuration of the bifid mandibular canal in a Korean population by using cone-beam computed tomography (CBCT) imaging. Materials and Methods: CBCT images of 1933 patients (884 male and 1049 female) were evaluated using PSR-9000N and Alphard-Vega 3030 Dental CT units (Asahi Roentgen Ind. Co., Ltd, Kyoto, Japan). Image analysis was performed by using OnDemand3D software (CyberMed Inc., Seoul, Korea). The bifid mandibular canal was identified and classified into four types, namely, the forward canal, buccolingual canal, dental canal, and retromolar canal. Statistical analysis was performed by using the chi-squared test and one-way analysis of variance (ANOVA). Results: Bifid mandibular canals were observed in 198 (10.2%) of 1933 patients. The most frequently observed type of bifid mandibular canal was the retromolar canal (n=104, rate: 52.5%) without any significant difference among the incidence of each age and gender. The mean diameter of the accessory canal was 1.27 mm (range: 0.27-3.29 mm) without any significant difference among the mean diameter of each type of the bifid mandibular canal. The mean length of the bifid mandibular canals was 14.97mm(range: 2.17-38.8 mm) with only a significant difference between the dental canal and the other types. Conclusion: The bifid mandibular canal is not uncommon in Koreans and has a prevalence of 10.2% as indicated in the present study. It is suggested that a CBCT examination be recommended for detecting a bifid canal.

• Imaging Science in Dentistry
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• 제48권1호
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• pp.11-19
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• 2018

Purpose: This study compared the diagnostic accuracy of cone-beam computed tomography (CBCT) scans obtained with 2 CBCT systems with high- and low-resolution modes for the detection of root perforations in endodontically treated mandibular molars. Materials and Methods: The root canals of 72 mandibular molars were cleaned and shaped. Perforations measuring 0.2, 0.3, and 0.4 mm in diameter were created at the furcation area of 48 roots, simulating strip perforations, or on the external surfaces of 48 roots, simulating root perforations. Forty-eight roots remained intact(control group). The roots were filled using gutta-percha (Gapadent, Tianjin, China) and AH26 sealer (Dentsply Maillefer, Ballaigues, Switzerland). The CBCT scans were obtained using the NewTom 3G (QR srl, Verona, Italy) and Cranex 3D (Soredex, Helsinki, Finland) CBCT systems in high- and low-resolution modes, and were evaluated by 2 observers. The chi-square test was used to assess the nominal variables. Results: In strip perforations, the accuracies of low- and high-resolution modes were 75% and 83% for NewTom 3G and 67% and 69% for Cranex 3D. In root perforations, the accuracies of low- and high-resolution modes were 79% and 83% for NewTom 3G and was 56% and 73% for Cranex 3D. Conclusion: The accuracy of the 2 CBCT systems was different for the detection of strip and root perforations. The Cranex 3D had non-significantly higher accuracy than the NewTom 3G. In both scanners, the high-resolution mode yielded significantly higher accuracy than the low-resolution mode. The diagnostic accuracy of CBCT scans was not affected by the perforation diameter.

• Korean Journal of Radiology
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• 제23권3호
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• pp.343-354
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• 2022

Objective: To develop and evaluate a deep learning-based artificial intelligence (AI) model for detecting skull fractures on plain radiographs in children. Materials and Methods: This retrospective multi-center study consisted of a development dataset acquired from two hospitals (n = 149 and 264) and an external test set (n = 95) from a third hospital. Datasets included children with head trauma who underwent both skull radiography and cranial computed tomography (CT). The development dataset was split into training, tuning, and internal test sets in a ratio of 7:1:2. The reference standard for skull fracture was cranial CT. Two radiology residents, a pediatric radiologist, and two emergency physicians participated in a two-session observer study on an external test set with and without AI assistance. We obtained the area under the receiver operating characteristic curve (AUROC), sensitivity, and specificity along with their 95% confidence intervals (CIs). Results: The AI model showed an AUROC of 0.922 (95% CI, 0.842-0.969) in the internal test set and 0.870 (95% CI, 0.785-0.930) in the external test set. The model had a sensitivity of 81.1% (95% CI, 64.8%-92.0%) and specificity of 91.3% (95% CI, 79.2%-97.6%) for the internal test set and 78.9% (95% CI, 54.4%-93.9%) and 88.2% (95% CI, 78.7%-94.4%), respectively, for the external test set. With the model's assistance, significant AUROC improvement was observed in radiology residents (pooled results) and emergency physicians (pooled results) with the difference from reading without AI assistance of 0.094 (95% CI, 0.020-0.168; p = 0.012) and 0.069 (95% CI, 0.002-0.136; p = 0.043), respectively, but not in the pediatric radiologist with the difference of 0.008 (95% CI, -0.074-0.090; p = 0.850). Conclusion: A deep learning-based AI model improved the performance of inexperienced radiologists and emergency physicians in diagnosing pediatric skull fractures on plain radiographs.

• 한국산업보건학회지
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• 제25권3호
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• pp.355-365
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• 2015

Objectives: This study was conducted to better understand the relationship between health effects and exposure to dusts from a briquette fuel complex in Ansim, Daegu, Korea. Methods: The subjects of this study consisted of 2,980 persons over 40 years old who had lived 20 years or more around a briquette fuel complex in Daegu. We conducted a questionnaire survey, and chest radiography was performed. In addition, chest computed tomography(CT) (335 cases) and pulmonary function test(PFT) (658 cases) were done. Pneumoconiosis was diagnosed if one of three radiologists determined(or suspected) pneumoconiosis. We also conducted in-depth interviews for pneumoconiosis cases. We defined the exposed group as subjects residing within a 500 meter radius from the walls of the briquette fuel complex, and the others were defined as the control group. Results: Subjects in the exposed and control groups are respectively 715(24%) and 2,265 cases(76%). Major respiratory symptoms in the exposed group such as sputum, dyspnea, chest tightness and wheezing were significantly higher than in the control group. By chest radiography, 173 cases of pneumoconiosis or suspicious pneumoconiosis were detected. By PFT, 62 cases(29.5%) of chronic obstructive pulmonary disease(COPD) among 210 asymptomatic subjects were detected. Finally, by chest CT we concluded 28 cases to be pneumoconiosis, and eight cases among them proved to be pneumoconiosis by environmental exposure. Conclusions: Through this study, we concluded that health outcomes such as respiratory symptoms, pneumoconiosis, and COPD were caused by continuous exposure to dusts from the briquette fuel complex. Policies to reduce environmental exposure are needed, and cases of environmental disease should be intensively followed up by the government.

• 대한한의학회지
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• 제35권4호
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• pp.104-109
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• 2014

Objectives: To present the case of a 76-year-old man diagnosed with idiopathic interstitial pneumonias (IIPs) treated exclusively with traditional Korean medicine (TKM). Methods: The patient was treated with the revised Sasammaekmundong-tang (rSMT), acupuncture, and pharmacopuncture from September 2013 to May 2014 in our outpatient clinic. We prescribed rSMT three times a day for 4 months. Acupuncture and pharmacopuncture were performed twice a week for 9 months. To evaluate therapeutic efficacy, we recorded the patient's chief complaints at each visit, and pulmonary function test was performed at intervals of three months. Chest radiography and chest computed tomography were performed before and after treatment, respectively. Results: During the course of the treatment, dyspnea, cough, sputum, and overall pulmonary function improved. Conclusions: We suggest that traditional Korean medicine (TKM) for IIPs patients might be effective in the control of the main symptoms of IIPs and in the recovery of respiratory function.

• 대한방사선기술학회지:방사선기술과학
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• 제32권2호
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• pp.147-151
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• 2009

ROC에 의한 의료영상을 평가하는 방법으로 지금까지는 5단계로 평가하는 평정확신도법이 일반적으로 사용되었다. 이 평정확신도법에서는 TPF나 FPF의 산출을 쉽게 구하는 것이 가능하나, 실험에 있어서 부드럽게 ROC곡선의 추정을 하기 위해서 관찰자에 대해 적당한 카테고리 배분이 요구되거나 또 짜여진 카테고리 배분을 위해 그 데이터가 무효해지는 경우가 많다. 이러한 문제를 해결하기 위해 또는 관찰실험 이외의 데이터에도 ROC해석의 응용이 가능해지도록 카테고리 분류가 되어 있지 않은 연속적으로 분포된 실험결과를 이용 ROC 해석을 행하는 방법인 연속확신도법이 보고 되었다. 하지만 국내에서는 의료영상의 평가에 연속확신도법을 적용한 예가 거의 없어서 흉부 디지털영상의 평가에 적용해 보았다. 그 결과 상용화된 프로그램에 의하여 부드러운 ROC곡선을 그릴 수 있었으며, 특성값을 쉽게 측정할 수 있어 디지털 의료영상의 평가에 적절히 사용될 수 있으리라 사료된다.