• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.11 s.254
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• pp.1051-1056
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• 2006

The mean and RMS velocity field of the respiratory gas flow in the 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 $\times$ 64 to 32 $\times$ 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.

• Journal of Veterinary Clinics
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• v.33 no.1
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• pp.6-9
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• 2016

Bronchoarterial (BA) ratio is a commonly used criterion to define airway dilatation despite the lack of normative human and animals. The objective of our study was to compare the range of normal bronchial to accompanying arterial diameter ratio with previous reports on CT scan of the thorax in dogs and assess influence anesthetics on BA ratio in dogs. Dogs undergoing multidetector CT scan of the chest for nonpulmonary conditions at a single center were prospectively identified. High-resolution reconstruction was performed on those included and both airway lumen and vessel diameters were measured in the lobar bronchi of the left cranial (cranial and caudal parts), right cranial, right middle, left caudal, and right caudal lung lobes. Eight dog were included; Mean of the mean BA ratios was $1.43{\pm}0.24$ (95% CI = 1.36 - 1.50) in inhalation anesthetic group. In propofol group, the mean of the mean BA ratios was $1.13{\pm}0.29$ (95% CI = 1.04 - 1.22). In medetomidine group, the mean of the mean BA ratios was $0.89{\pm}0.19$ (95% CI = 0.83 - 0.95). Comparing individual lobes within anesthetic category, there was no signicant difference in mean BA ratio between lung lobes or between dog according to inhalation, propofol, and medetomidine group (P = 0.630, P = 0.878, and P = 0.508, respectively). The BA ratio in these clinically normal dogs was consistent and may be a useful tool in evaluating for bronchiectasis on CT images. However, some different criteria for bronchiectasis were applied by the anesthetic methods.

• Tuberculosis and Respiratory Diseases
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• v.72 no.6
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• pp.501-506
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• 2012

Congenital cystic adenomatoid malformation (CCAM) is an uncommon, nonhereditary anomaly caused by arrest of lung. Patients with CCAM may present with respiratory distress as newborns, or may remain asymptomatic until later in life. CCAM type I is rarely found in association with bronchial atresia (BA) in adults; we present such a case. Case: A 54-year-old female presented with chronic cough and blood-tinged sputum. Physical examination and laboratory tests were unremarkable. Chest radiographs and a CT scan of the chest showed multiple large air-filled cysts consistent with a CCAM in the right lower lobe, and an oval-shaped opacity in the distal right middle lobal bronchus. Based on the radiologic findings, right middle lobectomy and a medial basal segmentectomy of the right lower lobe were performed via a thoracotomy. These lesions were consistent with Stocker's Type I CCAM and BA in the different lobes.

• Tuberculosis and Respiratory Diseases
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• v.43 no.4
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• pp.651-656
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• 1996

We have experienced a case of sarcoidosis appearing asymmetrical diffuse interstitial lung lesions with multiple lymphadenopathy. This patient was a 57 year-old female who had been in good health until 2 months ago. At that time she noted the onset of an exertional dyspnea and weakness. Pulmonary function tests showed moderate obstructive pattern with mild decreased DLco. In the chest CT, multiple lymphadenopathy with small nodular lesions are scattered, and the impression was a metastatic lymph nodes with lymphangitic carcinomatosis. In bronchofiberscopy, we noted luminal narrowing by extrinsic compression in the right middle and lower lobe bronchi. And microscopic examination of by bronchofiberscopic biopsy showed chronic inflammation. Thus we performed subcarinal and tight supraclaviclar lymph nodes aspiration biopsy cytology, and that revealed class 0 and class 1, respectively. Finally, we performed an excisional biopsy for the right scalene lymph node, which revealed the specimen as a noncaseating granuloma. The angiotensin convecting enzyme level was overt two folds compared to normal value. And the patient had negative PPD skin test and hyperglobulinemia. After 18 weeks treatment with prednisone, the signs and symptoms which the patient clad suffered from, disappeared.

• Tuberculosis and Respiratory Diseases
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• v.43 no.5
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• pp.792-797
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• 1996

A 59-year-old woman was admintted to the hospital because of intermittent fever and right side chest pain. She has a same episode eight months before this entry. Chest CT scan demonstrated ill-defined parenchymal consolidation containing dilated bronchi of right lower lung field, but no endobronchial mass in the bronchial trees. Fiberoptic bronchoscopy seeking the cause of recurrent pneumonia revealed a small, round mass nearly completely obstructing me lumen of basal segmental bronchus of right lower lobe. The diagnosis of bronchiolar papilloma was made from the biopsy specimens of the bronchoscopic examination. The patient was treated with right lower lobectomy because of irreversible secondary changes below the obstructed bronchus. This thoracotomic excision resulted in complete relief of symptoms and the postoperative course was uneventful for 12 months. Here we report a extremely rare umor with a brief review of literatures.

• Clinical and Experimental Pediatrics
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• v.45 no.5
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• pp.669-672
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• 2002

Nasal obstruction is a cause of respiratory distress in newborns. The congenital nasal airway obstructive abnormalities are classified into three forms according to the location: posterior choanal atresia, nasal cavity stenosis and congenital nasal pyriform aperture stenosis(CNPAS). CNPAS is located at the anterior part of the nasal fossa. CT is the study of choice to make the diagnosis of CNPAS and rule out other causes of nasal obstruction. Though conservative management of CNPAS is recommended, in cases of severe CNPAS surgical treatment should be considered. Calcification of cartilage in the larynx, trachea and bronchi is extremely rare in children. Such calcifications are generally discovered in young children with congenital stridor. The clinical course is favorable. No case with CNPAS and tracheal calcification is reported in newborn. We report a one-day-old girl with CNPAS and tracheal calcification who presented with respiratory difficulty immediately after birth.

• Tuberculosis and Respiratory Diseases
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• v.41 no.3
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• pp.277-288
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• 1994

Objectives : Multiple lung cancers and/or precancerous lesions can be developed because many bronchi are exposed to carcinogens simultaneously according to the concept of "Field Cancerization". We had performed a careful bronchoscopic examination and analysed the patients of double bronchial lesions who received the separate pathologic evaluation. Methods : We studied 21 patients of double bronchial lesions among 1855 patients of bronchoscopic examination from April 1990 to December 1993 in Korea Cancer Center Hospital. We classified the patients into three groups(double malignancies of different histology, double malignancies of same histology, and combination of malignant and benign lesions) and analysed the histologic type, location, radiologic findings, and clinical parameters. Results : Among 21 patients, six patients had double malignancies of different histology, eight had double malignancies of same histology, and seven had combination of malignant and benign lesions. Out of 14 double malignant cases, 11 cases are considered as synchronous multiple primary lung cancers. Combination of squamous cell carcinomas was found in 5 cases, combination of small cell carcinoma and squamous cell carcinoma was found in 4 cases. Combination of adenocarcinoma and squamous cell carcinoma and combination of squamous cell carcinoma and poorly differentiated carcinoma were found in 1 case respectively. All patients of synchtonous multiple primary lung cancers were male and had long smoking history(average 40 pack years). Among 21 cases of double bronchial lesions, only one lesion could be detected by prebronchoscopic radiologic examination including chest CT in 15 cases. Conclusions : The presence of double bronchial lesions including multiple primary lung cancers and the limitation of radiologic examination to detect early bronchial lesions encourage us to examine the whole bronchi carefully and to perform pathologic evaluations.

• Tuberculosis and Respiratory Diseases
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• v.49 no.2
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• pp.231-236
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• 2000

Benign metastasizing leiomyoma usually occurs in women and is associated with a past hysterectomy in 80% of the cases, which is a rare entity. The patient was a 39-year-old woman who complained of cough and sputum. She underwent hysterectomy because of benign leiomyoma ten years ago. Chest X-ray showed nodular lesion in the left lung field. Chest CT showed a 3cm sized round well defined mass at left hilum with mild indentation of segmental bronchi of left upper lobe and a small tiny nodule in right lower lung field. Nodular lesion of left upper 1000 was resected by thoracotomy. Pathological evaluation showed benign spindle-like cells having nuclei without cytotic atypia similar to those of benign leiomyoma. Immunohistochernical stainings for desmin and smooth muscle actin were positive. Therefore these nodules are considered as benign metastasizing leiomyoma from a uterine leiomyoma. We report this case with the review of literature.

• Korean Journal of Radiology
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• v.22 no.1
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• pp.131-138
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• 2021

Objective: Iterative reconstruction degrades image quality. Thus, further advances in image reconstruction are necessary to overcome some limitations of this technique in low-dose computed tomography (LDCT) scan of the chest. Deep-learning image reconstruction (DLIR) is a new method used to reduce dose while maintaining image quality. The purposes of this study was to evaluate image quality and noise of LDCT scan images reconstructed with DLIR and compare with those of images reconstructed with the adaptive statistical iterative reconstruction-Veo at a level of 30% (ASiR-V 30%). Materials and Methods: This retrospective study included 58 patients who underwent LDCT scan for lung cancer screening. Datasets were reconstructed with ASiR-V 30% and DLIR at medium and high levels (DLIR-M and DLIR-H, respectively). The objective image signal and noise, which represented mean attenuation value and standard deviation in Hounsfield units for the lungs, mediastinum, liver, and background air, and subjective image contrast, image noise, and conspicuity of structures were evaluated. The differences between CT scan images subjected to ASiR-V 30%, DLIR-M, and DLIR-H were evaluated. Results: Based on the objective analysis, the image signals did not significantly differ among ASiR-V 30%, DLIR-M, and DLIR-H (p = 0.949, 0.737, 0.366, and 0.358 in the lungs, mediastinum, liver, and background air, respectively). However, the noise was significantly lower in DLIR-M and DLIR-H than in ASiR-V 30% (all p < 0.001). DLIR had higher signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) than ASiR-V 30% (p = 0.027, < 0.001, and < 0.001 in the SNR of the lungs, mediastinum, and liver, respectively; all p < 0.001 in the CNR). According to the subjective analysis, DLIR had higher image contrast and lower image noise than ASiR-V 30% (all p < 0.001). DLIR was superior to ASiR-V 30% in identifying the pulmonary arteries and veins, trachea and bronchi, lymph nodes, and pleura and pericardium (all p < 0.001). Conclusion: DLIR significantly reduced the image noise in chest LDCT scan images compared with ASiR-V 30% while maintaining superior image quality.

• Tuberculosis and Respiratory Diseases
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• v.53 no.5
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• pp.510-518
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• 2002

Background : Bronchial anthracofibrosis (BAF) is a dark black or brown pigmentation of multiple large bronchi associated with a fibrotic stenosis or obliteration that is incidentally found during a diagnostic bronchoscopy some reporters have suggested endobronchial tuberculosis or tuberculous lymphadenitis as a possible cause of BAF. However, some BAF patients do not have any medical history of tuberculosis. The aim of this study was to elucidate the clinical features of simple BAF patients, which were not associated with tuberculosis. Methods : We reviewed the patients' charts retrospectiely and interviewed all BAF patients who were followed up for 1 year or more. Among the 114 BAF patients, 43 patents (38 %) had no associated tuberculosis, cancer and pneumoconiosis. The clinical characteristics, radiological findings and associated pulmonary diseases of these patients were evaluated. Results : Most patients were non-smokers, old aged, housewifes who resided in a farming village. The common respiratory symptoms were dyspnea, cough and hemoptysis. The predominant X-ray findings were a multiple bronchial wall thickening(89%), bronchial narrowing or atelectasis (76%) and a mediastinal lymph node enlargement with/without calcification (78%). Pulmonary function test usually showed mild obstructive ventilatory abnormalities but no patient showed a restrictive ventilatory pattern and the patients were frequently affected with chronic bronchitis(51%), post-obstructive pneumonia(40%) and chronic asthma(4%). Conclusion : Because BAF is frequently associated with chronic bronchitis and obstructive pneumonia as well as tuberculosis, a careful clinical evaluation and accurate differential diagnosis is more essential than empirical anti-tuberculous medication.