• Journal of Chest Surgery
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• v.33 no.10
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• pp.798-805
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• 2000

Background : the prediction on changes in the lung function after lung surgery would be an important indicator in terms of the operability and postoperative complications. In order to predict the postoperative FEV1 - the commonly used method for measuring changes in lung function- a comparison between the quantitative CT and the perfusion lung scan was made and proved its usefulness. Material and Method : The subjects included 22 patients who received perfusion lung scan and quantitative CT preoperatively and with whom the follow-up of PFT were possibles out of the pool of patients who underwent right lobectomy or right pneumonectomy between June of 1997 and December of 1999. The FEV1 and FVC were calibrated by performing the PFT on each patient and then the predicted FEV1 and FVC were calculated after performing perfusion lung scan and quantitative CT postoperatively. The FEV1 and FVC were calibrated by performing the PFT after 1 week and after 3 momths following the surgery. Results : There was a significant mutual scan and the actual postoperative FEV1 and FVC at 1 week and 3 months. The predicted FEV1 and FVC(pneumonectomy group : r=0.962 and r=0.938 lobectomy group ; r=0.921 and r=913) using quantitative CT at 1 week postoperatively showed a higher mutual relationship than that predicted by perfusion lung scan(pneumonectomy group : r=0.927 and r=0.890 lobectomy group : r=0.910 and r=0.905) The result was likewise at 3 months postoperatively(CT -pneumonectomy group : r=0.799 and r=0.882 lobectomy group : r=0.934 and r=0.932) Conclusion ; In comparison to perfusion lung scan quantitative CT is more accurate in predicting lung function postoperatively and is cost-effective as well. Therefore it can be concluded that the quantitative CT is an effective method of replacing the perfusion lung scan in predicting lung function post-operatively. However it is noted that further comparative analysis using more data and follow-up studies of the patients is required.

• Tuberculosis and Respiratory Diseases
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• v.57 no.2
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• pp.118-124
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• 2004

Lung cancer is the leading cause of cancer death for men and women in the industrialized world. It is desirable to detect disease at a stage when it is not causing symptoms and when control or cure is possible. If the screening test detects patients with the disease at an early stage, they can be examined to confirm the diagnosis and intervention can alter the natural history of the disease. The results of screening programs designed to detect early lung cancer using either conventional chest radiograph or sputum cytology are disappointing for a diagnostic screening test. Because of advances in helical CT imaging techniques, screening for lung cancer has been suggested as a possible method of improving outcome. Findings in recent publications suggest that substantial dose reduction is possible in chest CT. The advantages of low-dose CT are more sensitive than chest radiograph for detecting small pulmonary nodules that may be lung cancers, shorter scanning time than conventional chest CT scan without intravenous contrast injection, cheaper cost than standard CT, low radiation dose. However, the true clinical significance of the small tumors found by screening is still unknown, and their effect on mortality awaits future investigation. Furthermore, in addition to detecting an increased number of lung cancers, low-dose CT found at least one indeterminate nodule in many of all screened patients. The majority should be benign but evaluation of all these indeterminate nodules is not a trivial problem in routine practice. In conclusion, lung cancer screening with low-dose CT is a complex subject. The true effectiveness of lung cancer screening (a reduction in mortality from lung cancer) with low-dose CT can be determined through well-designed randomized control trials with enrolment of appropriate subjects.

• Journal of radiological science and technology
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• v.32 no.2
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• pp.129-140
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• 2009

As CT has been increasingly used as an accurate screening tool for lung disease, radiation dose becomes an important issue for both radiographers and patients. Many researches have been done for a low-dose CT as a screening tool for early detection of asymptomatic lung diseases. From those studies, it has been reported that chest dose rate from the low-dose CT is considerably lower than from standard CT. The patient dose is determined by scanning parameters such as kVp, mAs, pitch, scan time and the radiation risk of lung in screening examination may not be negligible. Herein, we suggest that Low-dose CT is useful as a screening tool in routine clinical practice on the basis of published articles, but further study is necessary because Low-dose CT has poor sensitivity and specificity for screening early stage of lung cancer according to the results of the studies. This article is to provide a brief overview of the screening examinations by Low-dose CT.

• Journal of Korea Multimedia Society
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• v.16 no.6
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• pp.700-707
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• 2013

In this paper, we propose a non-rigid registration method of lung parenchyma in temporal chest CT scans using region binarization modeling and locally deformable model. To cope with intensity differences between CT scans, we segment the lung vessel and parenchyma in each scan and perform binarization modeling. Then, we match them without referring any intensity information. We globally align two lung surfaces. Then, locally deformable transformation model is developed for the subsequent non-rigid registration. Subtracted quantification results after non-rigid registration are visualized by pre-defined color map. Experimental results showed that proposed registration method correctly aligned lung parenchyma in the full inspiration and expiration CT images for ten patients. Our non-rigid lung registration method may be useful for the assessment of various lung diseases by providing intuitive color-coded information of quantification results about lung parenchyma.

• Journal of Korea Multimedia Society
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• v.8 no.5
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• pp.641-650
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• 2005

In this parer, curve stopping function based on the CT number of lung parenchyma from CT lung images is proposed to detect lung region in replacement of conventional edge indication function in geodesic active contour model. We showed that the proposed method was able to detect lung region more effectively than conventional method by applying three kinds of measurement numerically. And, we verified the effectiveness of proposed method visually by observing the detection Procedure on actual CT images. Because lung parenchyma region could be precisely detected from actual EBCT (electron beam computer tomography) lung images, we were sure that the Proposed method could aid to early diagnosis of lung disease and local abnormality of function.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2352-2355
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• 2003

In recent yeas, studies on computer aided diagnosis (CAD) using image analysis on CT images have been conducted with respect to various diseases. Extracting ground-glass opacities (GGO) on lung CT images is one of such subjects, though it has not found an established method yet. If the region of ground-glass opacities is large on CT images, it can be detected without much difficulty. On the other hand, if the region is small, it is still difficult to find it exactly. In the latter case, increasing overlooking possibility cannot be avoided according to smaller size of the region. To solve this difficulty, this paper proposes an automatic technique for extracting ground-glass opacities on lung CT images employing some statistical parameters of a gray level histogram and a differential histogram. The proposed technique is applied to some lung CT images in the performed experiment. The results are shown with discussion on future work.

• Journal of Biomedical Engineering Research
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• v.44 no.5
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• pp.303-314
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• 2023

This study aimed to assess the practical feasibility of advanced deformable image registration (DIR) algorithms in radiotherapy by employing two distinct datasets. The first dataset included 14 4D lung CT scans and 31 head and neck CT scans. In the 4D lung CT dataset, we employed the DIR algorithm to register organs at risk and tumors based on respiratory phases. The second dataset comprised pre-, mid-, and post-treatment CT images of the head and neck region, along with organ at risk and tumor delineations. These images underwent registration using the DIR algorithm, and Dice similarity coefficients (DSCs) were compared. In the 4D lung CT dataset, registration accuracy was evaluated for the spinal cord, lung, lung nodules, esophagus, and tumors. The average DSCs for the non-learning-based SyN and NiftyReg algorithms were 0.92±0.07 and 0.88±0.09, respectively. Deep learning methods, namely Voxelmorph, Cyclemorph, and Transmorph, achieved average DSCs of 0.90±0.07, 0.91±0.04, and 0.89±0.05, respectively. For the head and neck CT dataset, the average DSCs for SyN and NiftyReg were 0.82±0.04 and 0.79±0.05, respectively, while Voxelmorph, Cyclemorph, and Transmorph showed average DSCs of 0.80±0.08, 0.78±0.11, and 0.78±0.09, respectively. Additionally, the deep learning DIR algorithms demonstrated faster transformation times compared to other models, including commercial and conventional mathematical algorithms (Voxelmorph: 0.36 sec/images, Cyclemorph: 0.3 sec/images, Transmorph: 5.1 sec/images, SyN: 140 sec/images, NiftyReg: 40.2 sec/images). In conclusion, this study highlights the varying clinical applicability of deep learning-based DIR methods in different anatomical regions. While challenges were encountered in head and neck CT registrations, 4D lung CT registrations exhibited favorable results, indicating the potential for clinical implementation. Further research and development in DIR algorithms tailored to specific anatomical regions are warranted to improve the overall clinical utility of these methods.

• Journal of Veterinary Clinics
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• v.31 no.5
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• pp.376-381
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• 2014

In this study, we analyzed the computed tomography (CT) measurements of lung volume and density in dogs with relation to body weight, age, sex, and breed. The multi-detector CT examination of the thorax was performed on dogs without respiratory or cardiovascular diseases. Three-dimensional reconstruction of CT images facilitated measurement of lung volume and density. There was a statistical significant correlation between body weight and lung volume (p < 0.0001). Lung density significantly decreased with an increase in body weight (p = 0.0078). However, no correlation was seen between these lung parameters and either sex or age of the dogs. In conclusion, this study shows that body weight is an important factor to consider when interpreting total lung volume and density values measured by quantitative CT. We highlight the need for further study using quantitative CT in identifying the potential effects of sex, age, and disease status on these parameters.

• Tuberculosis and Respiratory Diseases
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• v.58 no.2
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• pp.111-119
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• 2005

The introduction of high-resolution CT (HRCT) in recent years has improved the ability of radiologists to detect and characterize the diffuse infiltrative lung disease (DILD). The detection and diagnosis of diffuse lung disease using HRCT are based on the recognition of specific abnormal findings. In this article, pattern recognition of HRCT findings is reviewed in the differential diagnosis of diffuse infiltrative lung disease. In general, HRCT findings of lung disease can be classified into four categories based on their appearances. These categories consist of (1) nodules and nodular opacities, (2) linear and reticular opacities, (3) increased lung opacity, and (4) decreased lung opacity, including cystic lesions.

• Tuberculosis and Respiratory Diseases
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• v.63 no.6
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• pp.521-525
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• 2007

Positron emission tomography/computed tomography (PET/CT) is valuable for the diagnosis of malignancies. However, PET/CT is unable to discriminate exactly between inflammation and a neoplasm. We report a case of a 50-year-old man with pulmonary paragonimiasis that was suspicious for lung cancer, as detected by PET/CT. The use of PET/CT revealed multilobulated consolidation on the right lung and patchy consolidation on the left lung, with increased fluorodeoxyglucose (FDG) uptake. In addition, the left paraaortic lymph node (LN) and peripancreatic LN showed enlargement with increased FDG uptake. Lung cancer with multiple lymph node metastases was suspected from the increased standardized uptake values (SUV>4.5) determined by PET/CT. We performed wedge resection via video-assisted thoracic surgery (VATS) and found Paragonimus westermani eggs in the involved tissues.