• Tuberculosis and Respiratory Diseases
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• v.46 no.4
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• pp.564-573
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• 1999

Background: With variable symptoms and nonspecific radiographic appearances, pulmonary embolism (PE) is a frequent and often undiagnosed cause of mortality and morbidity. The Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) study suggested that the majority of patients undergoing ventilation-perfusion (V-Q) scan would require additional studies to establish or to exclude the diagnosis of PE. Pulmonary angiography has been regarded as gold standard for diagnosis of PE. However, it is an invasive procedure that may be associated with significant notable morbidity and mortality. Thus, availability of an accurate, noninvasive screening examination is highly desirable. Method: From October 1994 to February 1997, twenty patients (male 13, female 7, range 23-91 years, median 58 years) who were suspected as pulmonary embolism on the basis of clinical evidence and underwent the spiral volumetric computed tomography (spiral CT), were studied retrospectively to evaluate the effectiveness of spiral CT as a diagnostic tool in PE. Results: PE could be excluded with spiral CT in 4 patients ; diagnoses of these patients were lung cancer, pneumonia with lung abscess, bilateral pleural effusion due to congestive heart failure, nonspecific pulmonary abnormality retrospectively. One patient who disclosed high probability in V/Q scan, could be diagnosed as pneumonia with lung abscess and underlying emphysema with spiral CT. Among 4 patients who showed intermediate and low probability in V/Q scan, 3 patients could be confirmed as PE with spiral CT. Spiral CT was helpful in 3 patients, in whom V/Q scan could not be performed due to other reasons (e.g. night time, mechanical ventilation) to confirm the diagnosis of PE. Spiral CT could demonstrate embolus above lobar artery level in 11 patients, and up to segmental artery level in 5 patients. Conclusion: This study demonstrated that spiral CT could allow accurate demonstration of thrombotic clots in centrally localized embolism. Spiral CT could be effective, specific, noninvasive and useful diagnostic screening modality for the diagnosis of pulmonary embolism.

• Korean Journal of Head & Neck Oncology
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• v.30 no.1
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• pp.20-22
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• 2014

유리피판을 이용한 두경부 재건후 폐색전은 드물게 발생한다. 수술후 예상하기 힘들고 갑작스럽게 발생하기 때문에 환자가 아주 위험한 상황에 빠질 수 있다. 즉각적인 발견과 적절한 치료만이 환자의 생명을 구할 수 있다. 유리피판을 이용한 두경부 재건후 발생한 폐색전증 2예를 문헌고찰과 함께 보고하는 바이다.

• Journal of Chest Surgery
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• v.34 no.4
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• pp.373-376
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• 2001

만성 폐색전증으로 혈전 제거술을 하고 난 다음 기관지내 대량 출혈은 빈도는 적으나 상당히 높은 사망률을 보이는 합병증 중의 하나이다. 기관지내 대량 출혈이 생겼을 때 체외 막 산소화 장치와 각각 다르게 조절한 인공호흡기 2대를 이용하여 특별한 휴유증 없이 잘 치료한 경험을 하였기에 보고하는 바이다.

• Tuberculosis and Respiratory Diseases
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• v.64 no.4
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• pp.266-271
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• 2008

Background: Estimation of the probability of a patient having an acute pulmonary embolism (PE) for patients with a suspected PE are well established in North America and Europe. However, an assessment of the prediction rules for a PE has not been clearly defined in Korea. The aim of this study is to assess the prediction rules for patients with a suspected PE in Korea. Methods: We performed a retrospective study of 210 inpatients or patients that visited the emergency ward with a suspected PE where computed tomography pulmonary angiography was performed at a single institution between January 2005 and March 2007. Simplified Wells rules and revised Geneva rules were used to estimate the clinical probability of a PE based on information from medical records. Results: Of the 210 patients with a suspected PE, 49 (19.5%) patients had an actual diagnosis of a PE. The proportion of patients classified by Wells rules and the Geneva rules had a low probability of 1% and 21%, an intermediate probability of 62.5% and 76.2%, and a high probability of 33.8% and 2.8%, respectively. The prevalence of PE patients with a low, intermediate and high probability categorized by the Wells rules and Geneva rules was 100% and 4.5% in the low range, 18.2% and 22.5% in the intermediate range, and 19.7% and 50% in the high range, respectively. Receiver operating characteristic curve analysis showed that the revised Geneva rules had a higher accuracy than the Wells rules in terms of detecting PE. Concordance between the two prediction rules was poor ($\kappa$ coefficient=0.06). Conclusion: In the present study, the two prediction rules had a different predictive accuracy for pulmonary embolisms. Applying the revised Geneva rules to inpatients and emergency ward patients suspected of having PE may allow a more effective diagnostic process than the use of the Wells rules.

• Journal of Chest Surgery
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• v.42 no.4
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• pp.492-496
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• 2009

Background: The treatment of acute pulmonary embolism is difficult, and it can be lethal when cardiogenic shock is involved with major pulmonary embolism. In the past, pulmonary embolectomy was considered as the last choice for patients with pulmonary embolism. Accordingly, we analyzed our experience with seven cases of pulmonary embolectomy as an alternative option for the early treatment of pulmonary embolism. Material and Method: A retrospective analysis of medical charts of all patients who underwent pulmonary embolectomy at our hospital over the past eight years was performed. The patients were observed during their hospital stay and followed until their last visit to the outpatient department. Result: Among 7 patients (4 men and 3 women), 4 had massive pulmonary embolism, and 3 had sub massive pulmonary embolism. An extracorporeal membrane oxygenator was inserted in 3 patients before surgery. There was no mortality, and postoperative echocardiography showed no pulmonary hypertension in 6 patients. Conclusion: Pulmonary embolectomy can be performed with minimal mortality. We think that the use of an extracorporeal membrane oxygenator in patients with cardiogenic shock before surgery improves survival.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.703-706
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• 2004

나선형 CT 혈관촬영에서 획득한 영상의 분석를 통해서 폐색전증이 의심되는 부위를 자동으로 검출하는 방법으로, 연구 대상은 20명의 환자를 대상으로 분석하였으며 CT 검사 후 방사선과 의사가 정상소견을 받은 환자 5명과 폐색전증이 있는 판독소견을 가진 15명을 대상으로 비교 분석하였다. CT 검사하는 동안에 조영제를 투입하면, 폐색전증이 발생한 부위는 조영제 양과 분포가 불균등하여 명암값이 낮게 검출된다. 검출방법으로는 전처리 작업으로 폐영역만을 분할하고, 분할된 폐영역에서 혈관을 찾기 위해 모폴로지기법를 적용하여 세선화(thinning) 작업을 진행한다. 다음 공정으로는 경계선을 찾아 local watershed를 적용하여 혈관을 검출하고, 검출된 혈관내에서 원형모델을 적용하여 모폴로지(morphology)을 통해 국소 부위의 미세한 농도변화를 인지하여 색전이 발생한 영역을 자동검출하였다. 본 논문의 자동검출시스템에서는 색전증이 있는 경우에 true positive의 발생빈도는 case 당 4.5개가 검출되었다. 정상인의 경우에도 혈류의 흐름, 혈류의 분기점, 노이즈로 인한 false positive의 빈도는 case 당 2.6개가 발생하여 전체적으로 false positive는 5.2개가 검출되었다. 본 논문은 false positive의 비율이 높게 검출되었지만 폐영역 CT 검사의 컴퓨터지원진단시스템(computer aided diagnosis)의 향후 연구과제에 방향을 제시할 수 있을 것이라 사료된다.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.05a
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• pp.393-396
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• 2021

폐색전증(Pulmonary Embolism : PE)은 사망률이 높은 질환중 하나이다. 초기에 정확한 진단 및 치료를 시행하는 경우 사망과 재발의 경우가 흔치 않으나 지연 진단이 일어나는 경우 사망률은 높기 때문에 보다 정확하고 빠른 검사법이 필요하다. 본 연구에서는 폐색전증 환자의 흉부 CT 데이터를 가지고 딥러닝 알고리즘을 생성하여 소프트웨어를 구현하고자 한다. 개발된 딥러닝 기반의 폐색전증 진단 보조 소프트웨어는 CT 촬영 후 즉각적인 질환 예측으로 판독 시간의 단축과 효율성을 제공할 것으로 기대된다.

• Tuberculosis and Respiratory Diseases
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• v.43 no.1
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• pp.69-74
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• 1996

Background: The diagnosis of pulmonary embolism (PE) based on clinical findings is often elusive and therefore requires confirmative diagnostic method. Pulmonary angiography, though the gold standard for the diagnosis of pulmonary embolism, is an invasive method and requires trained personnel and special equipment. Lung V/Q scan, on the other hand, is a noninvasive method but the diagnostic specificity and sensitivity arc not satisfactory in case that the results are either intermediate or low probability scan. Plasma D-dimer is generated when a thrombus is fibrinolysed by plasmin and is known to be increased in various thrombotic disorders. The aim of this study was to investigate the value of the determination of plasma D-dimer level in the diagnosis of pulmonary embolism. Methods: Pulmonary angiography was performed in 17 patients who were clinically suspected to have pulmonary embolism. 9 patients(PE, $56{\pm}13.4$ yrs, M:F=8:1) were diagnosed to have pulmonary embolism by pulmonary angiography. The control group were the 8 patients with negative pulmonary angiography and 13 orthopedic patients with no evidence of pulmonary embolism on scintigraphic and impedance plethysmographic studies(n=21) (non-PE, $54.5{\pm}11.1$ yrs, M:F=11:10). Plasma D-dimer was measured by latex agglutination method in study subjects and the results were analyzed according to the presence or absence of pulmonary embolism. Results: 1) The increased level of plasma D-dimer was more frequently observed in the patients with pulmonary embolism than in the controls(>0.5 mg/L, 8 in PE, 10 in non-PE; <0.5 mg/L, 1 in PE, 11 in non-PE, p=0.049). 2) The diagnostic value of plasma D-dimer level higher than 0.5 mg/L were as follows: sensitivity 88.9%(8/9), specificity 52.4%(11/21), positive predictive value 44.4%(8/18), and negative predictive value 91.7%(11/12). Conclusion: Plasma D-dimer determination showed high sensitivity and negative predictive value in the diagnosis of pulmonary embolism and is therefore thought to be useful in excluding the possibility of pulmonary embolism.

• Tuberculosis and Respiratory Diseases
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• v.66 no.3
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• pp.211-215
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• 2009

Pulmonary thromboembolism occurs in old patients with risk factors, such as, immobilization, chronic medical disease, trauma, a hereditary hypercoagulable state, and others. However, we experienced a young man with a massive pulmonary thromboembolism attributed to immobilization due to computer gaming. The patient had been playing computer games in a seated position for at least five hour continually, and for twelve hours per day over a two-week period. The 36-year-old patient was transferred to our institute rule out the possibility of an acute myocardial infarction. Computer tomography revealed intraluminal filling defects in the distal main pulmonary artery and the left popliteal vein. He received thrombolytic therapy and subsequently recovered without complications. This case raises the possibility that prolonged computer gaming is a risk factor of thromboembolism in young adults.

• Tuberculosis and Respiratory Diseases
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• v.47 no.5
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• pp.669-680
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• 1999

Background: Pulmonary thromboembolism(PTE) is a life threatening disease that needs early diagnosis. Spiral CT angiography depict thromboemboli in the central pulmonary vessels with greater than 90% sensitivity and specificity, which approaches the results of pulmonary angiography in the Prospective Investigation of Pulmonary Embolism Diagnosis(PIOPED) study. This study was performed to evaluate the findings and the diagnostic value(clinical utility) of the spiral CT angiography with 2D image(multiplanar reformation) and 3D images(Shaded surface display, Minimal intensity projection) in the pulmonary thromboembolism. Methods: We retrospectively analysed spiral CT angiography and pulmonary angiography, lung scan and clinical recordings of 20 patients who had PTE diagnosed by spiral CT angiography(n=19 cases) or pulmonary angiography(n=l case) from September 1997 to August 1998. Among 20 patients who had underwent spiral CT angiography, 14 patients could be performed lung perfusion scan at the same time. We analyzed the vascular and parenchymal change in spiral CT angiogram. Results: Anatomical distribution of PTE was as follows: 1) left lung(n= 103)