• Journal of Biomedical Engineering Research
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• v.38 no.5
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• pp.237-241
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• 2017

Early detection of the pulmonary nodule is important for diagnosis and treatment of lung cancer. Recently, CT has been used as a screening tool for lung nodule detection. And, it has been reported that computer aided detection(CAD) systems can improve the accuracy of the radiologist in detection nodules on CT scan. The previous study has been proposed a method using Convolutional Neural Network(CNN) in Lung CAD system. But the proposed model has a limitation in accuracy due to its sparse layer structure. Therefore, we propose a Deep Convolutional Neural Network to overcome this limitation. The model proposed in this work is consist of 14 layers including 8 convolutional layers and 4 fully connected layers. The CNN model is trained and tested with 61,404 regions-of-interest (ROIs) patches of lung image including 39,760 nodules and 21,644 non-nodules extracted from the Lung Image Database Consortium(LIDC) dataset. We could obtain the classification accuracy of 91.79% with the CNN model presented in this work. To prevent overfitting, we trained the model with Augmented Dataset and regularization term in the cost function. With L1, L2 regularization at Training process, we obtained 92.39%, 92.52% of accuracy respectively. And we obtained 93.52% with data augmentation. In conclusion, we could obtain the accuracy of 93.75% with L2 Regularization and Data Augmentation.

• Tuberculosis and Respiratory Diseases
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• v.41 no.5
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• pp.562-567
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• 1994

Signet ring cell carcinoma has been previously described in many organs, most frequently in the stomach, and rarely in the colon, rectum, gallbladder, pancreas, breast, nadsal cavity, prostate, urinary bladder and ureter. Signet ring cell carcinomas in the lung, especially, when examined by small biopsies, are generally believed to be metastatic. This case was diagnosed by bronchoscopic biopsy. We also examined various organs by noninvasive method, including UGI series, barium enema and abdomen CT scan, but all studies were nomal. Patient received cisplatin and etoposide combination chemotherapy followed by local radiotherapy as a primary non-small cell lung cancer. Patient died of his disease 6 months after diagnosis. Now we report a case of primary signet ring cell carcinoma of the lung.

• Tuberculosis and Respiratory Diseases
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• v.52 no.4
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• pp.419-424
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• 2002

A 44 year old man was admitted complaining fo exertional dyspnea. The patient denied any occupational history of hard metal exposure. Chest radiography showed an increased interstitial marking at the peripheral portion of both lower lung fields. The spirometric values were within the normal ranges. However, the diffusion capacity of the lungs was lower. In the bronchial lavage fluid, the characteristic multinucleated giant cells were noticed, and the macrophage compartment was 96% and the neutrophils were 4%. High-resolution CT scan revealed ground glass opacities with emphysematous lung changes at the peripheral portion of the whole lung. An open lung biopsy confirmed the presence of numerous multinucleated giant cells (define GIP) with an associated interstitial fibrosis throughout the lung. The radiographic abnormailities and symptoms subsequently improved following treatment with oral corticosteroids.

• Tuberculosis and Respiratory Diseases
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• v.74 no.4
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• pp.191-194
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• 2013

Mycobacterium chelonae lung disease is very rare. We report a case of lung disease caused by M. chelonae in a previously healthy woman. A 69-year-old woman was referred to our hospital because of hemoptysis. A computed tomography (CT) scan of the chest revealed bronchiolitis associated with bronchiectasis in the lingular division of the left upper lobe. Nontuberculous mycobacteria were isolated three times from sputum specimens. All isolates were identified as M. chelonae by various molecular methods that characterized rpoB and hsp65 gene sequences. Although some new lesions including bronchiolitis in the superior segment of the left lower lobe developed on the chest CT scan 35 months after diagnosis, she has been followed up without antibiotic therapy because of her mild symptoms. To the best of our knowledge, this is the first case of M. chelonae lung disease in Korea in which the etiologic organisms were confirmed using molecular techniques.

• Progress in Medical Physics
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• v.26 no.4
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• pp.267-272
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• 2015

In this study, the reduction of dose and risk was evaluated from using automatic mA control in 4D CT scan of patients whose organ movement was considered for gated radiotherapy. The organ doses, CTDI, effective doses from 4D CT with and without using automatic mA control were evaluated using CT-Expo program for each 10 patients of liver and lung cancer, and the risk of exposure induced death and loss of life expectancy were evaluated using PCXMC program. It was founded that there were 26.8%, and 15.5% dose reduction in organ doses and CTDI for liver and lung cancer patients and 16.5% and 19.8% risk reduction in liver and lung cancer patients. The organ doses and effective doses were evaluated for the parameter of each patient used in CT scans, and risks considering age and gender could be evaluated. It was founded that there were 21.2% dose reduction and 18.2% risk reduction in 4D CT scan using AEC for liver and lung cancer patients.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.3
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• pp.252-254
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• 2007

Image fusion is fast catching attention as Wagner pointed out in his 2006 version of the recent progress and development presented at the annual meeting of Society of Nuclear Medicine. Prototypical fusion of bone scan and radiograph was already attempted at in 1961 when Fleming et al. published an article on strontium-85 bone scan. They simply superimposed dot scan on radiograph enabling simultaneous assessment of altered bone metabolism and local bone anatomy. Indeed the parallel reading of images of bone scan and radiography, CT, MRI or ultrasonography has been practiced in nuclear medicine long since. It is fortunate that recent development of computer science and technology along with the availability of refined CT and SPECT machines has permitted us to open a new avenue to digitally produce precise fusion image so that they can readily be read, exchanged and disseminated using internet. Ten years ago fusion was performed using Bresstrahlung SPECT/CT and it is now achievable by PET/CT and SPECT/CT software and SPECT/CT hardware. The merit of image fusion is its feasibility of reliable assessment of morphological and metabolic change. It is now applicable not only to stationary organs such as brain and skeleton but also to moving organs such as the heart, lung and stomach. Recently, we could create useful fusion image of cardiac SPECT and 64-channel CT angiograph. The former provided myocardial metabolic profile and the latter vascular narrowing in two patients with coronary artery stenosis and myocardial ischemia. Arterial stenosis was severe in Case 1 and mild in Case 2.

• Journal of Radiation Protection and Research
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• v.43 no.1
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• pp.1-9
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• 2018

Background: In this study, we investigate the image quality of virtual monochromatic images synthesized from dual-energy computed tomography (DECT) at voltages of 80/140 kV and 100/140 kV. Materials and Methods: Virtual monochromatic images of a phantom are synthesized from DECT scans from 40 to 70 keV in steps of 1 keV under the two combinations of tube voltages. The dose allocation of dual-energy (DE) scan is 50% for both low- and high-energy tubes. The virtual monochromatic images are compared to single-energy (SE) images at the same radiation dose. In the DE images, noise is reduced using the 100/140 kV scan at the optimal monochromatic energy. Virtual monochromatic images are reconstructed from 40 to 70 keV in 1-keV increments and analyzed using two quality indexes: noise and contrast-to-noise ratio (CNR). Results and Discussion: The DE scan mode with the 100/140 kV protocol achieved a better maximum CNR compared to the 80/140 kV protocol for various materials, except for adipose and brain. Image noise is reduced with the 100/140 kV protocol. The CNR values of DE with the 100/140 kV protocol is similar to or higher than that of SE at 120 kV at the same radiation dose. Furthermore, the maximum CNR with the 100/140 kV protocol is similar to or higher than that of the SE scan at 120 kV. Conclusion: It was found that the CNR achieved with the 100/140 kV protocol was better than that with the 80/140 kV protocol at optimal monochromatic energies. Virtual monochromatic imaging using the 100/140 kV protocol could be considered for application in breast, brain, lung, liver, and bone CT in accordance with the CNR results.

• Journal of Chest Surgery
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• v.42 no.2
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• pp.226-232
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• 2009

Background: Blunt chest trauma accounts for 90% of all chest traumas in Europe and the United States and this causes 20% of all trauma-related deaths. The major cause of morbidity and mortality after blunt chest trauma is undetected injuries. For this reason, chest computerized tomography has gained popularity for the evaluation of trauma, but it is expensive and it exposes patients to radiation. This study identified the clinical features associated with the diagnosic information obtained on a CT chest scan, as compared with a standard chest X-ray, for patients who sustained blunt trauma to the chest. This study also evaluated the role of a routine computed tomographic (CT) scan for these patients. The patients who had chest computed tomography done after the initial chest x-ray were analyzed separately for the presence of occult injuries. Material and Method: We studied 100 consecutive patients from November 2006 to July 2007: 74 patients after motor vehicle crashes and 26 patients after a fall from a height >2m. Simultaneous with the initial clinical evaluation, an anteroposterior chest radiograph and a helical chest CT scan were obtained for all the patients. The data extracted from the medical record included the vital signs, the interventions and the type and severity of injury (RTS). Result: Among the 100 cases, 79 patients showed at least more than one pathologic sign on their chest radiograph, and 21 patients had a normal chest radiograph. For 17 of the patients who had a normal chest X ray, the CT scan showed multiple injuries, which were pneumothorax, hemothorax, lung contusion, sternal fracture etc. This represents that a CT scan is statistically superior to a chest radiograph to diagnose the pathologic signs. But on the other hand, as for treatment, only 31 patients were diagnosed by CT scan and they were treated with chest tube insertion ect. 42 patients needed ony conservative management without invasive thoracosurgical treatment such as chest tube insertion or open thoracotomy. 27 patients were treated based on the diagnosis made by the chest radiograph and physical examination. Conclusion: Chest computerized tomography was significantly more effective than routine chest X-ray for detecting lung contusion, pneumothorax and mediastinal hematoma, as well as fractured ribs, scapula and, sternum. Although the occult findings increased, the number of patients who needed treatment was small. Therefore, we suggest making selective use of a CT scan to avoid its overuse in ERs.

• Tuberculosis and Respiratory Diseases
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• v.57 no.4
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• pp.381-385
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• 2004

Pulmonary gangrene is a rare and severe complication of bacterial pneumonia, where a pulmonary segment or lobe is sloughed due to parenchymal devitalization of the parenchyma, with secondary anaerobic infection and necrosis caused by pulmonary vascular thrombosis. Prior to the antibiotic era, massive pulmonary gangrene was potentially fatal. Herein, a case of pulmonary gangrene in a 67-year-old man is reported. He complained of fever, chills, dyspnea and purulent sputum of 5 days duration. The plain chest radiograph showed well-marginated right upper lobe consolidation, with bulging minor fissure, suggestive of a Klebsiella infection. A contrast CT scan demonstrated consolidation of the right upper lobe, with a central necrotizing portion. Klebsiella species was confirmed from both sputum and blood cultures. After appropriate antibiotics, the chest X-ray and CT scan 3 weeks later showed a large cavity with an air-fluid level, sloughing-off and extrusion of necrotic lung tissue, suggestive of pulmonary gangrene. Seven months later, the right gangrenous lung showed severe volume loss on a chest radiograph. The management of pulmonary gangrene has been somewhat controversial. Herein, it was managed without surgical drainage or resection. If the antibiotic therapy had failed, then a surgical approach would have been considered.

• Journal of Yeungnam Medical Science
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• v.33 no.1
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• pp.72-75
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• 2016

Pulmonary epithelioid hemangioendothelioma (PEH) is a rare, low-to-intermediate malignant tumor of endothelial origin. Computed tomography (CT) findings of PEH demonstrate multiple small bilateral nodules; however, to the best of our knowledge, there were no reports on PEH coexisting with other malignancies. Here, we reported on a case involving PEH in a patient with colon cancer and breast cancer which was misconceived as pulmonary meta- stasis. A 63-year-old woman who suffered from constipation for 2 weeks visited our hospital. Colonoscopy showed a large mass with obstruction on hepatic flexure. The histological diagnosis was adenocarcinoma of the ascending colon. Multiple nodules in both lungs and breast were observed on a chest CT scan. A core biopsy of a breast nodule was performed and a diagnosis of invasive ductal carcinoma of the left breast was made. Pulmonary nodules observed on the chest CT scan was considered as pulmonary metastasis from colon or breast cancer. Laparoscopic right hemicolectomy was performed. At the same time, wedge resection of the lung was performed and pathological diagnosis was PEH. Radiologic features of PEH were difficult to distinguish from lung metastasis. Therefore the author reported a rare case involving PEH in a patient with primary malignancy of colon and breast.