• Korean Journal of Bronchoesophagology
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• v.17 no.1
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• pp.50-52
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• 2011

Ectopic thyroid gland is a defined as thyroid tissue located in a site other than its usual pre-tracheal location. Ultrasound examination, CT scan, thyroid scan, and thyroid iodine uptake test are all valuable modalities for a differential diagnosis. Although most of cases are asymptomatic, treatment is indicated when there are symptoms related to progressive growth of mass. This article reports a ectopic thyroid cyst in the anterior neck that was similar to deep neck infection accompanied by acute airway obstruction.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06c
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• pp.320-322
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• 2012

코 내부의 복잡한 기하학적 형상으로 인해 nasal airway의 분리는 많은 어려움을 겪고 있다. 본 논문은 velocimetry of nasal airflow 와 코 수술 계획을 위하여 3차원 공간에서 nasal airway를 interactive semiautomatic으로 분리하고 시각화하는 방법을 제안한다. 제안하는 방법은 ROI(Region-Of-Interest)와 multi-seed 3d region growing(MS3RG)기법을 적용하여 비강을 분리하며 볼륨렌더링 기법을 이용하여 분리된 영역을 3차원 공간에서 직관적으로 확인 할 수 있다. 또한 분리된 3차원 비강 모델은 유동흐름 실험을 위하여 3차원 프린터를 통해 실제 모형으로 제작 가능하다. 그리하여 CT dataset(512*512*175)을 가지고 매뉴얼 세그멘테이션에서 5시간 정도 걸리던 작업을 반자동 세그멘테이션 방법을 이용할 경우 최대 3분 이내에 분리 작업을 완료할 수 있으며 수치해석 실험 및 물리 실험에 이용할 수 있다.

• Journal of the Korean Society of Visualization
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• v.18 no.3
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• pp.96-102
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• 2020

Oral cancer surgery changes the morphologic characteristics of the human upper airway. These changes can affect the flow patterns. In this study, computational fluid dynamics (CFD) simulations with transient solver were performed to numerically investigate the air flows in the human upper airways depending oral cancer surgery. 3D reconstructed models were obtained from 2D CT images of one patient. For the boundary condition, the realistic breathing cycle of human was applied. The hydraulic diameters of cross-sections for post-surgical model are changed greatly along streamwise direction, so these variations can cause higher wall shear stress and flow disturbance compared to pre-surgical model. The recirculation flows observed in the protruding region result in the relatively large pressure drop. These results can be helpful to understand the flow variations after resection surgery of oral cancer.

• Korean Journal of Radiology
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• v.1 no.3
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• pp.159-161
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• 2000

The authors present a case of histologically proven bronchus-associated lymphoid tissue (BALT) lymphoma of the lung in a patient with primary Sjögren's syndrome that manifested on thin-section CT scan as a mosaic pattern of inhomogeneous attenuation due to mixed small airway and infiltrative abnormalities

• Tuberculosis and Respiratory Diseases
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• v.72 no.1
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• pp.8-14
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• 2012

Background: Although airway obstruction in chronic obstructive pulmonary disease (COPD) is due to pathologic processes in both the airways and the lung parenchyma, the contribution of these processes, as well as other factors, have not yet been evaluated quantitatively. We therefore quantitatively evaluated the factors contributing to airflow limitation in patients with COPD. Methods: The 213 COPD patients were aged >45 years, had smoked >10 pack-years of cigarettes, and had a post-bronchodilator forced expiratory volume in one second ($FEV_1$)/forced vital capacity (FVC) <0.7. All patients were evaluated by medical interviews, physical examination, spirometry, bronchodilator reversibility tests, lung volume, and 6-minute walk tests. In addition, volumetric computed tomography (CT) was performed to evaluate airway wall thickness, emphysema severity, and mean lung density ratio at full expiration and inspiration. Multiple linear regression analysis was performed to identify the variables independently associated with $FEV_1$ - the index of the severity of airflow limitation. Results: Multiple linear regression analysis showed that CT measurements of mean lung density ratio (standardized coefficient ${\beta}$=-0.46; p<0.001), emphysema severity (volume fraction of the lung less than -950 HU at full inspiration; ${\beta}$=-0.24; p<0.001), and airway wall thickness (mean wall area %; ${\beta}$=-0.19, p=0.001), as well as current smoking status (${\beta}$=-0.14; p=0.009) were independent contributors to $FEV_1$. Conclusion: Mean lung density ratio, emphysema severity, and airway wall thickness evaluated by volumetric CT and smoking status could independently contribute to the severity of airflow limitation in patients with COPD.

• Journal of the Korean Society of Radiology
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• v.84 no.5
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• pp.1123-1133
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• 2023

Purpose Our study aimed to evaluate the association between automated quantified body composition on CT and pulmonary function or quantitative lung features in patients with chronic obstructive pulmonary disease (COPD). Materials and Methods A total of 290 patients with COPD were enrolled in this study. The volume of muscle and subcutaneous fat, area of muscle and subcutaneous fat at T12, and bone attenuation at T12 were obtained from chest CT using a deep learning-based body segmentation algorithm. Parametric response mapping-derived emphysema (PRM^emph), PRM-derived functional small airway disease (PRM^fSAD), and airway wall thickness (AWT)-Pi10 were quantitatively assessed. The association between body composition and outcomes was evaluated using Pearson's correlation analysis. Results The volume and area of muscle and subcutaneous fat were negatively associated with PRM^emph and PRM^fSAD (p < 0.05). Bone density at T12 was negatively associated with PRM^emph (r = -0.1828, p = 0.002). The volume and area of subcutaneous fat and bone density at T12 were positively correlated with AWT-Pi10 (r = 0.1287, p = 0.030; r = 0.1668, p = 0.005; r = 0.1279, p = 0.031). However, muscle volume was negatively correlated with the AWT-Pi10 (r = -0.1966, p = 0.001). Muscle volume was significantly associated with pulmonary function (p < 0.001). Conclusion Body composition, automatically assessed using chest CT, is associated with the phenotype and severity of COPD.

• Korean Journal of Radiology
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• v.19 no.6
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• pp.1187-1195
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• 2018

Objective: To compare correlations between pulmonary function test (PFT) results and different reconstruction algorithms and to suggest the optimal reconstruction protocol for computed tomography (CT) quantification of low lung attenuation areas and airways in healthy individuals. Materials and Methods: A total of 259 subjects with normal PFT and chest CT results were included. CT scans were reconstructed using filtered back projection, hybrid-iterative reconstruction, and model-based IR (MIR). For quantitative analysis, the emphysema index (EI) and wall area percentage (WA%) were determined. Subgroup analysis according to smoking history was also performed. Results: The EIs of all the reconstruction algorithms correlated significantly with the forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) (all p < 0.001). The EI of MIR showed the strongest correlation with FEV1/FVC (r = -0.437). WA% showed a significant correlation with FEV1 in all the reconstruction algorithms (all p < 0.05) correlated significantly with FEV1/FVC for MIR only (p < 0.001). The WA% of MIR showed the strongest correlations with FEV1 (r = -0.205) and FEV1/FVC (r = -0.250). In subgroup analysis, the EI of MIR had the strongest correlation with PFT in both eversmoker and never-smoker subgroups, although there was no significant difference in the EI between the reconstruction algorithms. WA% of MIR showed a significantly thinner airway thickness than the other algorithms ($49.7{\pm}7.6$ in ever-smokers and $49.5{\pm}7.5$ in never-smokers, all p < 0.001), and also showed the strongest correlation with PFT in both ever-smoker and never-smoker subgroups. Conclusion: CT quantification of low lung attenuation areas and airways by means of MIR showed the strongest correlation with PFT results among the algorithms used, in normal subjects.

• Radiation Oncology Journal
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• v.14 no.2
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• pp.123-128
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• 1996

Purpose : This is a retrospective study to compare the Palliation rates, survival rates and complications of low dose rate and high dose rate endobronchial brachytherapy in the management of malignant airway obstruction. Materials and methods : Forty three consecutive patients with malignant airway compromise from primary or metastatic lung tumors were treated with low dose rate(LDR) endobronchial Iridium-192 insertion(21 patients) between October 1988 and June 1992, and high dose rate(HDR) endobronchial brachytherapy(22 patients) between August 1992 and April 1994 with palliative aim Flexible fiberoptic bronchoscopy under fluoroscopic control was utilized in all 91 procedures. Twenty seven LDR Procedures delivered a dose of 5-7.5 Gy to a 1.0 cm radius respectively. Results : Subjective and objective responses to treatments were evaluated on follow-up examinations by clinical examination, chest x-rays and CT scan of the chest on some patients. Fifteen of 21 LDR patients and 19 of 22 HDR Patients showed subjective improvement in terms of better breathing and less Productive cough as well as complete disappearance of hemoptysis. Objective improvement on chest x-rays and CT scan of the chest had been demonstrated on 8 LDR Patients and 10 HDR patients. Conclusion : The technique of LDR and HDR endobronchial brachytherapy is simple and well tolerated procedure with minimal morbidity It Provides excellent palliation by keeping airway Patent in these short life-spanned patients.

• Tuberculosis and Respiratory Diseases
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• v.59 no.2
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• pp.133-141
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• 2005

"소기도"라 일컬어지는 해부학적 부위는 말단부 막성 세기관지와 호흡성 세기관지로 구성된 직경 3 mm 이하의 기도부위이다. 방사선학적으로는 고해상 전산화단층촬영(CT)에서 흉막직하의 직경 약 1.0 cm으로 이루어진 2차 소엽내의 중심부에 위치하게 된다. 그러므로 이 부위의 질환때에는 중심소엽성 세기관지내의 가득찬 물질로 인해 나타나는 중심소엽성 결절들과 선상음영들이 보인다. 이외의 소견으로는 중심소엽성 폐기종, 모자이크 모양의 폐음영, 분절하 무기폐등이 있고, 호기시 CT 촬영에서 나타나는 공기포획이 있다. 최근에는 다검출기형식의 CT (multidetector CT)의 발전으로 인하여 이차원 재구성 (2 dimension reformat) 관상면, 시상면 CT 스캔을 매우 명확하고 빨리 얻을 수 있고, 기관지에 대한 삼차원 볼륨 영상 (3 dimentional volume rendering image) 등을 얻어서 가시적인 효과를 높이고 진단의 정확성에 보다 더 접근하게 되었다. 소기도를 침범하는 질환은 일차적인 것과 이차적인 것이 있는데, 병리조직학적으로는 원인별로 흡연으로 인한 소기도 질환, 세포성 세기관지염, 수축성 세기관지염, 증식성 세기관지염등으로 구분하며 여기에는 이와 같은 병리질환을 일으키는 다양한 원인들이 포함된다. 이외에도 드문 질환으로 미만성 범세기관지염, 광물질에 의한 소기도 질환등이 있다.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.39
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• pp.22.1-22.9
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• 2017

Background: Two-jaw surgery including mandibular and maxillary backward movement procedures are commonly performed to correct class III malocclusion. Bimaxillary surgery can reposition the maxillofacial bone together with soft tissue, such as the soft palate and the tongue base. We analyzed changes of pharyngeal airway narrowing to ascertain clinical correlations with the prevalence of snoring after two-jaw surgery. Methods: A prospective clinical study was designed including a survey on snoring and three-dimensional (3D) computed tomography (CT) in class III malocclusion subjects before and after bimaxillary surgery. We conducted an analysis on changes of the posterior pharyngeal space find out clinical correlations with the prevalence of snoring. Results: Among 67 subjects, 12 subjects complained about snoring 5 weeks after the surgical correction, and examining the 12 subjects after 6 months, 6 patients complained about the snoring. The current findings demonstrated the attenuation of the largest transverse width (LTW), anteroposterior length (APL), and cross-sectional area (CSA) following bimaxillary surgery given to class III malocclusion patients, particularly at the retropalatal level. The average distance of maxillary posterior movements were measured to be relatively higher (horizontal distance 3.9 mm, vertical distance 2.6 mm) in case of new snorers. Conclusions: This study found that bimaxillary surgery could lead to the narrowing of upper airway at the retropalatal or retroglossal level as well as triggering snoring in subjects with class III malocclusion. Based on the current clinical findings, we also found that upper airway narrowing at retropalatal level may contribute to increasing the probability of snoring and that polysonography may need to be performed before orthognathic surgery in subjects with class III malocclusion.