• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.2
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• pp.173-181
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• 2014

In this paper, the algorithm that can automatically segment the lung, the airway and the pulmonary vessels in a chest CT was proposed. The proposed method is progressed in three steps. In the first step, the lung and the airway are segmented by the region growing law through the optimal threshold and three-dimensional labeling. In the second, from the start point to the first carina of the airway is segmented by the deduction operation, and the next airway of the bifurcations are segmented by applying a variable threshold technique. In the third step, the left/right lungs are divided by the restoration process for the lung, and the outside of lungs for abnormal is checked by applying the advanced rolling ball algorithm, and if abnormal is found, that part is removed, and it is restored to the normal lungs by connecting the outside of the lung in the form of second-order polynomial. Finally, pulmonary vessels are segmented by applying the three-dimensional connected component labeling method and three-dimensional region growing method. As the results of simulation, it could be confirmed that the pulmonary vascular is accurately divided without loss of tissue around lung.

• Tuberculosis and Respiratory Diseases
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• v.70 no.1
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• pp.10-20
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• 2011

Various diseases can diffusely involve central airways, including the trachea and main stem bronchi. Central airway abnormalities are frequently not apparent or are overlooked on chest radiographs, even though the patient may have significant symptoms. Recent advances in spiral and multi-detector computed tomography (CT) with multi-planar reconstruction and three-dimensional demonstration, including virtual bronchoscopy, allow for excellent display of central airway anatomy and abnormalities with visualization of accurate locations of lesions. Early detection and proper diagnosis of airway diseases based on various radiographic findings will help determine appropriate treatment, including surgical planning and evaluation of treatment response. Herein we describe and illustrate the imaging findings of a wide spectra of diffuse central airway diseases.

• Tuberculosis and Respiratory Diseases
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• v.47 no.2
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• pp.209-217
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• 1999

Backgrounds: To investigate the role of CT as a screening tool and to compare the diagnostic accuracy with that of the fiberoptic bronchoscopy (FOB) in evaluating the causes of hemoptysis. Methods: The retrospective review of plain chest radiograph, CT and FOB was done in 72 patients with hemoptysis. The diagnosis were confirmed by histology (n=33), bacterial culture (n=6), cytology (n=3), serology (n=2), skin test (n= 1), clinical response (n=5), and airway disease mainly by HRCT (n=22). Results: The causes of hemoptysis were shown to be lung cancer (n=29), bronchiectasis (n=19), tuberculosis (n=12), aspergilloma (n=5), invasive aspergillosis (n=l), COPD (n=3) and others (n=3). The sensitivity was 100% and 91,7% by CT and FOB respectively. The diagnostic compatibility was 95.8% and 59.7% by CT and FOB respectively. The diagnostic compatibility in cases with central airway disease was 96.3% and 100 % in CT and FOB. In parenchymal disease, CT and FOB showed 91.3 % and 43.5 % of compatibility, respectively. airway disease, CT and FOB showed 100% and 31.8% compatibility, respectively. That is to say, CT has higher sensitivity and diagnostic compatibility than FOB for identifying the causes of hemoptysis, and is more helpful for patients with hemoptysis from parenchymal or airway disease. FOB had the advantage in obtaining histologic, cytologic and bacteriologic diagnosis with biopsy or washing Conclusion: CT should be used as the screening method before performing FOB for patients with hemoptysis who have normal or nonspecific findings or peripheral airway disease in plain chest radiograph.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.60.1-60.1
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• 2005

• Journal of Broadcast Engineering
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• v.18 no.5
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• pp.702-712
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• 2013

In this paper, we proposed an algorithm that extracts the airway and lung without loss of information in spite of the pulmonary vessel and nodules of the chest wall in the chest CT images. We use a mask image in order to improve the performance and to save processing time of airway and lung segmentation. In the second step, by converting left and right lungs to binary image using the morphological information, we have removed the solitary pulmonary nodule to identify the value of the threshold lung and the chest wall. The last step is to connect the outer shell of the lung with cubic Spline interpolation by adding the perfect pixel and computing the distance of the removed part. Experimental results using Matlab verified that the proposed method could overcome the drawbacks of the conventional methods.

• Korean Journal of Radiology
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• v.20 no.4
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• pp.631-640
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• 2019

Objective: To evaluate the value of airway computed tomography (CT) in patients with obstructive sleep apnea (OSA) as a predictor of cerebrocardiovascular disease (CCVD) clinically, by quantitatively analyzing carotid arterial calcification (CarAC). Materials and Methods: This study included 287 patients aged 40-80 years, who had undergone both polysomnography (PSG) and airway CT between March 2011 and October 2015. The carotid arterial calcium score (CarACS) was quantified using the modified Agatston method on each upper airway CT. The OSA severity was categorized as normal, mild, moderate, and severe using the PSG results. Clinical characteristics, comorbid diseases, and lipid profiles of all patients were analyzed, and the prevalence of CCVDs was investigated during the follow up period (52.2 ± 16.0 months). Results: CCVD occurred in 27 patients (9.3%) at the end of follow-up, and the CCVD-present groups showed a significantly older mean age (57.5 years vs. 54.2 years), higher prevalence of hypertension (59% vs. 34%) and CarAC (51.9% vs. 20.8%), whereas sex, other comorbid diseases, and severity of OSA were not significantly different from the CCVD-absent group. A univariate analysis showed that age, hypertension, incidence of CarAC, and CarACS were risk factors for the occurrence of CCVD events. In a multivariate analysis, the incidence of CarAC was the only independent risk factor for CCVD. Conclusion: CarAC is an independent risk factor for CCVD, whereas the severity of OSA is not a contributory risk factor in patients with OSA. Therefore, additional analysis of CarACS based on airway CT scans may be useful for predicting CCVD.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.5
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• pp.295-304
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• 2012

Objectives: Lateral cephalometry, computed tomography (CT) and full-night polysomnography were used to examine the correlation of obstructive sleep apnea (OSA) severity. Materials and Methods: A total of 29 patients (5 females, 24 males) diagnosed with OSA were evaluated by lateral cephalometry, CT and full-night polysomnography. Lateral cephalometry was performed in the closed and open mouth states. The radiographic and polysomnography measurements of the patients with OSA were evaluated statistically to determine the association with OSA severity. Results: A significant relationship was observed between the increased respiratory disturbance index and closing lateral cephalometry. With mouth opening, the airway space narrowed and the OSA worsened. Lateral cephalometry revealed OSA patients to have an inferiorly positioned hyoid bone, longer-than-normal soft palate and narrowing airway space. As OSA was severe, the airway shape was ovoid in the CT horizontal view. Conclusion: Polysomnography and the radiographic parameter can be used for diagnosing OSA.

• Korean Journal of Radiology
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• v.22 no.10
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• pp.1719-1729
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• 2021

Objective: Emphysema and small-airway disease are the two major components of chronic obstructive pulmonary disease (COPD). We propose a novel method of quantitative computed tomography (CT) emphysema air-trapping composite (EAtC) mapping to assess each COPD component. We analyzed the potential use of this method for assessing lung function in patients with COPD. Materials and Methods: A total of 584 patients with COPD underwent inspiration and expiration CTs. Using pairwise analysis of inspiration and expiration CTs with non-rigid registration, EAtC mapping classified lung parenchyma into three areas: Normal, functional air trapping (fAT), and emphysema (Emph). We defined fAT as the area with a density change of less than 60 Hounsfield units (HU) between inspiration and expiration CTs among areas with a density less than -856 HU on inspiration CT. The volume fraction of each area was compared with clinical parameters and pulmonary function tests (PFTs). The results were compared with those of parametric response mapping (PRM) analysis. Results: The relative volumes of the EAtC classes differed according to the Global Initiative for Chronic Obstructive Lung Disease stages (p < 0.001). Each class showed moderate correlations with forced expiratory volume in 1 second (FEV₁) and FEV₁/forced vital capacity (FVC) (r = -0.659-0.674, p < 0.001). Both fAT and Emph were significant predictors of FEV₁ and FEV₁/FVC (R² = 0.352 and 0.488, respectively; p < 0.001). fAT was a significant predictor of mean forced expiratory flow between 25% and 75% and residual volume/total vital capacity (R² = 0.264 and 0.233, respectively; p < 0.001), while Emph and age were significant predictors of carbon monoxide diffusing capacity (R² = 0.303; p < 0.001). fAT showed better correlations with PFTs than with small-airway disease on PRM. Conclusion: The proposed quantitative CT EAtC mapping provides comprehensive lung functional information on each disease component of COPD, which may serve as an imaging biomarker of lung function.

• 한국가시화정보학회:학술대회논문집
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• 2005.12a
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• pp.93-98
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• 2005

The mean and RMS velocity field of the respiratory gas flow in tile human airway was studied experimentally by particle image velocimetry(PIV). Some researchers investigated the airflow for the mouth breathing case both experimentally and numerically. But it is very rare to investigate the airflow of nose breathing in a whole airway due to its geometric complexity. We established the procedure to create a transparent rectangular box containing a model of the human airway for PIV measurement by combination of the RP and the curing of clear silicone. We extend this to make a whole airway including nasal cavities, larynx, trachea, and 2 generations of bronchi. The CBC algorithm with window offset (64*64 to 32*32) is used for vector searching in PIV analysis. The phase averaged mean and RMS velocity distributions in Sagittal and coronal planes are obtained for 7 phases in a respiratory period. Some physiologic conjectures are obtained. The main stream went through the backside of larynx and trachea in inspiration and the frontal side in expiration. There exist vortical motions in inspiration, but no prominent one in expiration.

• Tuberculosis and Respiratory Diseases
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• v.70 no.1
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• pp.63-68
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• 2011

Multiple symmetrical lipomatosis (MSL), also called Madelung's disease, is a rare disorder of unknown etiology and characterized by abnormal accumulation of large subcutaneous fatty masses in neck, shoulder, and upper trunk. MSL has known to predominantly affect middle-aged men with a history of alcoholism. Although the clinical course of MSL is considered to be slowly progressive, in advanced stage, fatty masses in the neck may compress the upper aerodigestive tract, resulting in dyspnea and dysphagia. The treatment of MSL is surgical resection, but radical excision is very difficult and recurrence after surgery is frequent. We report the case of 55-year-old man with long lasting MSL, which caused severe airway obstruction. This patient was admitted with progressive dyspnea and massive accumulation of fat around the vocal cord that was detected on a neck CT scan. This abnormal fatty infiltration in supraglottic region caused upper airway obstruction.