• Journal of Chest Surgery
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• 제33권10호
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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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• 제57권2호
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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.

• 대한방사선기술학회지:방사선기술과학
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• 제32권2호
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• pp.129-140
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• 2009

전산화 단층촬영은 폐질환의 정밀진단 방법으로 사용이 증가되고 있다. 통상적으로 시행되는 CT촬영은 조기 진단을 위한 선별검사로써는 높은 방사선 노출과 고비용, 조영제 사용으로 인한 부작용 등으로 적당하지 않다. 영상의학분야에서 방사선을 이용한 CT촬영은 진단 능력이 우수한 반면 피폭선량 또한 매우 높아 선량 감축을 위한 노력이 절실하다. 그동안 많은 연구들에서 무증상기의 폐암 및 폐질환을 조기 발견하기 위한 선별검사로써 저선량 CT의 유용성에 대해 이루어져 왔고, 의미있는 결과를 보고하였다. 선량 감소에 많은 인자가 관여하고 있지만 조사선량(mAs)의 감소가 가장 많이 사용되고 있다. 이미 보고 된 많은 연구에서 저선량 CT는 폐질환을 조기 발견하기 위한 선별검사로써 임상에서 사용하기에 유용하지만, 일부 연구에서 조기 폐암을 예측할 수 있는 작은 결절을 발견하는데 낮은 민감도와 특이도를 보였고, 실제 생존율 증가에는 기여하지 못한 보고도 있었다. 따라서, 지금까지의 저선량 CT에 대한 연구결과를 토대로 다양한 위험에 노출된 집단을 대상으로 선량을 감소시키기 위한 연구가 계속적으로 이루어진다면, 향후 저선량 CT촬영은 폐암을 비롯한 폐질환의 조기진단 방법으로써 통상적으로 사용되고 있는 표준 CT촬영을 충분히 대체할 수 있을 것으로 전망한다.

• 한국멀티미디어학회논문지
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• 제16권6호
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• pp.700-707
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• 2013

본 논문에서는 시간차 흉부 CT 영상의 폐 실질 비강체 정합을 위하여 영역 이진화 모델링과 지역적 변형 모델을 이용한 정합 기법을 제안한다. 제안 기법은 먼저 폐 혈관과 실질을 분할하고, 영역 이진화 모델링을 수행하여 두 영상 사이의 밝기값의 차이에 따른 정합 오차를 최소화 한다. 다음으로 초기 정합 기법으로 두 폐 표면을 전역적으로 정렬하고, 지역적 변형 변환 모델을 제안하여 비강체 정합을 수행한다. 또한, 정합 후 감산된 시간에 따른 밝기값 차이가 미리 정의된 칼라 맵을 이용하여 가시화 된다. 실험 결과는 제안기법이 10명의 환자에 대하여 최대호흡과 최소호흡 CT 영상에서 폐 실질을 정확하게 정합하였음을 보여주었다. 제안된 비강체 정합 기법은 폐 실질에 대한 정량적 분석 결과의 직관적인 칼라 매핑을 통하여 다양한 폐 질환의 정량적 분석에 유용하게 사용될 수 있다.

• 한국멀티미디어학회논문지
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• 제8권5호
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• pp.641-650
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• 2005

본 논문에서는 지오데식 동적 윤곽선 모델에서 곡선을 물체의 경계에 수렴시키기 위하여 사용되는 기존의 에지지시함수를 대신하여 CT 폐영상에서 폐실질 영역의 CT계수를 기반으로 하는 곡선제어함수를 제안하였다. 제안한 방법이 기존의 방법보다 폐실질 영역을 잘 검출할 수 있음을 세 가지 척도를 이용하여 보였다. 실제 폐영상에 적용시켜 폐실질 검출 과정과 결과를 시각적으로 관측함으로써 제안한 방법의 유효성을 검증하였다. 제안한 방법을 이용하여 실제 EBCT(electron beam computer tomography) 폐 영상에서 폐실질 영역이 정확하게 검출되었으므로 폐질환 및 국소적 폐기능 이상을 조기진단에 도움을 줄 수 있음을 확인하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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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.

• 대한의용생체공학회:의공학회지
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• 제44권5호
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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.

• 한국임상수의학회지
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• 제31권5호
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• pp.376-381
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• 2014

컴퓨터단층촬영을 이용하여 개에서 폐용적과 폐밀도를 측정하였으며, 체중, 나이, 성별 및 품종에 따라 분석하였다. 데이터 수집을 위해 호흡기 질환이나 심혈관계질환이 없는 개에서 수행된 흉부 컴퓨터단층촬영 영상이 사용되었으며, 전체 폐용적과 밀도의 측정을 위해 컴퓨터단층촬영 영상의 재구성 기법을 이용하였다. 폐용적은 체중이 증가할수록 통계적으로 유의적인 증가를 보였다(p < 0.0001). 폐밀도는 체중이 증가함에 따라 유의적으로 감소하였다(p = 0.0078). 그러나, 폐용적과 밀도는 성별 또는 연령과 상관 관계를 보이지 않았다. 따라서, 정량적 컴퓨터단층촬영 검사로 전체 폐용적이나 폐밀도를 평가할 때 체중으로 인한 효과가 고려되어야 한다.

• Tuberculosis and Respiratory Diseases
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• 제58권2호
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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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• 제63권6호
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• pp.521-525
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• 2007

FDG-PET/CT는 악성종양 발견에 많은 기여를 하고 있는 영상진단법이지만, 염증성 질환에서 위양성을 보일 수 있다. 저자들은 국내외적으로 보고된 바가 많지 않은 PET/CT에서 양쪽 폐, 복부 림프절과 왼쪽 궁둥이의 증가된 FDG 섭취로 폐암으로 의심된 폐흡충증을 경험하였기에 문헌고찰과 함께 보고한다.