• Korean Journal of Radiology
• /
• v.21 no.4
• /
• pp.431-441
• /
• 2020

Objective: To compare the diagnostic performance and interobserver variability of strain ratio obtained from one or two regions of interest (ROI) on breast elastography. Materials and Methods: From April to May 2016, 140 breast masses in 140 patients who underwent conventional ultrasonography (US) with strain elastography followed by US-guided biopsy were evaluated. Three experienced breast radiologists reviewed recorded US and elastography images, measured strain ratios, and categorized them according to the American College of Radiology breast imaging reporting and data system lexicon. Strain ratio was obtained using the 1-ROI method (one ROI drawn on the target mass), and the 2-ROI method (one ROI in the target mass and another in reference fat tissue). The diagnostic performance of the three radiologists among datasets and optimal cut-off values for strain ratios were evaluated. Interobserver variability of strain ratio for each ROI method was assessed using intraclass correlation coefficient values, Bland-Altman plots, and coefficients of variation. Results: Compared to US alone, US combined with the strain ratio measured using either ROI method significantly improved specificity, positive predictive value, accuracy, and area under the receiver operating characteristic curve (AUC) (all p values < 0.05). Strain ratio obtained using the 1-ROI method showed higher interobserver agreement between the three radiologists without a significant difference in AUC for differentiating breast cancer when the optimal strain ratio cut-off value was used, compared with the 2-ROI method (AUC: 0.788 vs. 0.783, 0.693 vs. 0.715, and 0.691 vs. 0.686, respectively, all p values > 0.05). Conclusion: Strain ratios obtained using the 1-ROI method showed higher interobserver agreement without a significant difference in AUC, compared to those obtained using the 2-ROI method. Considering that the 1-ROI method can reduce performers' efforts, it could have an important role in improving the diagnostic performance of breast US by enabling consistent management of breast lesions.

• Korean Journal of Radiology
• /
• v.22 no.6
• /
• pp.959-969
• /
• 2021

Objective: This study aimed to evaluate the role of preoperative two-dimensional (2D) shear wave elastography (SWE) in assessing the stages of liver fibrosis in patients with suspected biliary atresia (BA) and compared its diagnostic performance with those of serum fibrosis biomarkers. Materials and Methods: This study was approved by the ethical committee, and written informed parental consent was obtained. Two hundred and sixteen patients were prospectively enrolled between January 2012 and October 2018. The 2D SWE measurements of 69 patients have been previously reported. 2D SWE measurements, serum fibrosis biomarkers, including fibrotic markers and biochemical test results, and liver histology parameters were obtained. 2D SWE values, serum biomarkers including, aspartate aminotransferase to platelet ratio index (APRi), and other serum fibrotic markers were correlated with the stages of liver fibrosis by METAVIR. Receiver operating characteristic (ROC) curves and area under the ROC (AUROC) curve analyses were used. Results: The correlation coefficient of 2D SWE value in correlation with the stages of liver fibrosis was 0.789 (p < 0.001). The cut-off values of 2D SWE were calculated as 9.1 kPa for F1, 11.6 kPa for F2, 13.0 kPa for F3, and 15.7 kPa for F4. The AUROCs of 2D SWE in the determination of the stages of liver fibrosis ranged from 0.869 to 0.941. The sensitivity and negative predictive value of 2D SWE in the diagnosis of ≥ F3 was 93.4% and 96.0%, respectively. The diagnostic performance of 2D SWE was superior to that of APRi and other serum fibrotic markers in predicting severe fibrosis and cirrhosis (all p < 0.005) and other serum biomarkers. Multivariate analysis showed that the 2D SWE value was the only statistically significant parameter for predicting liver fibrosis. Conclusion: 2D SWE is a more effective non-invasive tool for predicting the stage of liver fibrosis in patients with suspected BA, compared with serum fibrosis biomarkers.

• Tuberculosis and Respiratory Diseases
• /
• v.44 no.4
• /
• pp.899-906
• /
• 1997

Background : The percutaneous pleural needle biopsy have been regarded as cornerstone in the diagnosis of lymphocyte dominant pleural effusions of which acid fast bacilli smear and cytologic exam was negative. However, the complications of percutaneous pleural needle biopsy is not rare and its diagnostic efficacy is not always satisfactory. Recently, pleural fluid adenosine deaminase (ADA) and carcinoembryonic antigen (CEA) are widely accepted as markers of tuberculous pleurisy and malignant pleural effusion respectively. We designed this study to re-evaluate the role of percutaneous pleural needle biopsy in the diagnosis of lymphocyte dominant exudative pleural effusions whose AFB smear, cytologic exam was negative. Method : Retrospective analysis of 73 cases of percutaneous pleural needle biopsy in case of lymphocyte dominant exudative pleural effusions whose AFB smear and cytoloic exam was negative from Jan 1994 to Feb 1996 was done. Result : In 35 cases, specific diagnosis was obtained(all cases were tuberculous pleurisy), and in 30 cases specific diagnosis was not obtained in spite of getting adequate pleural tissues, and in the other 8 cases, percutaneous pleural biopsy failed to get pleural tissues. In 9 cases, complications were combined including pneuomothorax and hemothorax. All 49 cases of pleural effusions whose ADA value was higher than 40IU/L and satisfying other categories were finally diagnosed as tuberculous pleurisy, however, the pleural biopsy confirmed only 28 cases as tuberculous pleurisy. In 6 cases of pleural effusions of which CEA value is higher than 10ng/ml, the pleural biopsy made specific diagnosis in no case. Final diagnosis of above 6 cases consisted of 4 malignant effusions, 1 malignancy associated effusion and 1 tuberculous pleurisy. Conclusion : In the diagnosis of 73 cases of lymphocyte dominant pleural effusions of which acid fast bacilli smear and cytologic exam was negative, percutaneous pleural biopsy diagnosed only in 35 cases. In the diagnosis of tuberculous pleurisy, the positive predictive value of higher ADA than 40 IU/L in lymphocyte dominant pleural effusion with negative AFB smear and negative cytologic exam was 100%. And the diagnostic efficacy of pleural biopsy was 57%. In cases of effusions with high CEA than 10ng/ml 83% and 0% respectively. Finally, we concluded that percutaneous pleural needle biopsy in the diagnosis of AFB smear negative and cytologic exam negative lymphocyte dominant exudative pleural effusion was not obligatory. especially in effusions with high ADA and low CEA value.

• Clinical and Experimental Pediatrics
• /
• v.45 no.5
• /
• pp.654-658
• /
• 2002

Purpose : Endocrine and immune systems are connected and interdependent. Adrenal glands play an important role in this network and control the balance between serum levels of dehydroepiandrosterone sulfate(DHEAS) and cortisol. These steroids have an antagonistic effect on the T cell progression into Th1 and Th2 cells and on the induction of correlated interleukins. Therefore we evaluated the role of adrenal androgen and cortisol as immune modulators in Kawasaki disease( KD) with changes of T cell immunity. Methods : From April to August in 2001, we examined serum DHEAS and 24 hour urine free cortisol(F) before administration of immunoglobulin and steroids by radioimmunoassay in 14 KD patients. It's clinical severity was determined by Harada score and coronary lesion. Results : The age of the patient group ranged from 4 months to 4 years; its average age was 2.3 years. Three patients(21.4%) were below 1 year, 2(14.3%) between 1 and 2 years, 5(35.7%) between 2 and 3 years, 4(28.6%) between 3 and 4 years of age. Male to female ratio was 1:1.3. DHEAS was significantly decreased in patients($11.1{\pm}6.0{\mu}g/dL$) more than controls($81.6{\pm}13.3{\mu}g/dL$)(P<0.05). Twenty-four hour urine free cortisol was significantly increased in patients($36.9{\pm}21.9{\mu}g/dL$) more than controls($13.6{\pm}5.5{\mu}g/dL$)(P<0.05). Ratio of DHEAS/F was decreased remarkably in patients($0.33{\pm}0.20$) more than controls($6.65{\pm}2.56$)(P=0.016). There was no difference between ratio of DHEAS/F and Harada score, but its ratio was very low in patients with coronary aneurysm. Conclusion : These data demonstrate that there are changes of DHEAS and cortisol in acute stage of KD and the dis-equilibrium between two steroids may be relevant in the T cell immune response induction of Kawasaki disease. These changes support the use of DHEAS/F ratio as one of the predictive factors of coronary arteries complication.

• Tuberculosis and Respiratory Diseases
• /
• v.43 no.3
• /
• pp.377-387
• /
• 1996

Background : In 1980, WHO made a definition in which the term "impairment" as applied to the respiratory system is used to describe loss of lung function, "disability" the resulting diminution in exercise capacity. The measurement of pulmonary function during exercise would give us information about overall functional capacity and respiratory performance that would be lacking in tests performed at rest. We conducted this study to investigate the role of resting pulmonary function test and exercise test for assessing impairment/disability in patients with chronic airflow obstruction(CAO). Method : We studied 19 patients with CAO. The spirometry and body plethysmograph were performed in stable condition. And then patients performed a progressive incremental exercise test to a symptom-limited maximum using cycle ergometer. Patients were divided in two groups, severe and non-severe impairment, according to the resting PFTs and compaired each other. A patient was considered to be severely impaired if FVC < 50 %, FEV1 < 40 % or FEV1/FVC < 40 %. Results : 1) The airway obstruction and hypoxemia of severe impairment group were more severe and exercise performance was markedly reduced compairing to non-severe impairment group. 2) The severe impairment group showed ventilatory limitation during exercise test and the limiting symptomes ware dyspnea in 9/10 patients. 3) The impairment and disability of the patients with tuberculous destructed lung were most marked in patients with CAO. 4) The FEV1 was the most prevalent criterion for the determination of severe impairment based on resting PFTs and was the valuable best correlated to V02max(r=0.81, p < 0.001). 5) The sensitivity of exercise limits for predicting severe disability according to resting PFTs was 80 % and specificity 89 %. Conclusion : In patients with severe CAO, FEV1 is a good predictive of exercise performance and impairment measured by resting PFTs can predict a disability by exercise test.

• Development and Reproduction
• /
• v.13 no.1
• /
• pp.1-11
• /
• 2009

Implantation itself is governed by an array of endocrine, paracrine and autocrine modulators, of embryonic and maternal origin. Window of implantation is the unique temporal and spatial expression of factors allows the embryo to implant via signaling, appositioning, attachment, and invasion in a specific time frame of $2{\sim}4$ days. When the embryo has arrived in the uterine cavity, a preprogrammed sequence of events occurs, which involves the production and secretion of a multitude of biochemical factors such as cytokines, growth factors, and adhesion molecules by the endometrium and the embryo, thus leading to the formation of a receptive endometrium. Cytokines such as LIF, CSF-1, and IL-1 have all been shown to play important roles in the cascade of events that leads to implantation. Integrin, L-selectin ligands, glycodelin, mucin-1, HB-EGF and pinopodes are involved in appositioning and attachment. The embryo also produces cytokines and growth factors (ILs, VEGF) and receptors for endometrial signals such as LIF, CSF-1, IGF and HB-EGF. The immune system and angiogenesis play an important role. The usefulness of these factors to assess endometrial receptivity and to estimate the prognosis for pregnancy in natural and artificial cycles remains to be proven. Integrins, pinopodes, glycodelin and LIF (from biopsies) are promising candidates; from uterine flushings, glycodelin and LIF are also candidates. The ideal serum marker is not available, but VEGF, glycodelin and CSF have some clinical implications. Further evaluation that includes larger groups of infertile women and fertile controls are needed to elucidate whether their presence in plasma, flushing fluid, or endometrial samples can be used as some kind of a screening tool to assess endometrial function and prognosis for pregnancy before and after artificial reproductive therapy. A better understanding of their function in human implantation may lead to therapeutic intervention, thereby improving the success rate in reproduction treatment. New molecular techniques are becoming available for measuring both embryonic and endometrial changes prior to and during implantation. The use of predictive sets of markers may prove to be more reliable than a single marker. Ultimately, the aim is to use these tools to increase implantation in artificial cycles and consequently improve live-birth rates.

• Tuberculosis and Respiratory Diseases
• /
• v.43 no.6
• /
• pp.882-893
• /
• 1996

Background : Over one-third of solitary pulmonary nodules are malignant, but most malignant SPNs are in the early stages at diagnosis and can be cured by surgical removal. Therefore, early diagnosis of malignant SPN is essential for the lifesaving of the patient. The incidence of pulmonary tuberculosis in Korea is somewhat higher than those of other countries and a large number of SPNs are found to be tuberculoma. Most primary physicians tend to regard newly detected solitary pulmonary nodule as tuberculoma with only noninvasive imaging such as CT and they prefer clinical observation if the findings suggest benignancy without further invasive procedures. Many kinds of noninvasive procedures for confirmatory diagnosis have been introduced to differentiate malignant SPNs from benign ones, but none of them has been satisfactory. FOG-PET is a unique tool for imaging and quantifying the status of glucose metabolism. On the basis that glucose metabolism is increased in the malignant transfomled cells compared with normal cells, FDG-PET is considered to be the satisfactory noninvasive procedure which can differentiate malignant SPNs from benign SPNs. So we performed FOG-PET in patients with solitary pulmonary nodule and evaluated the diagnostic accuracy in the diagnosis of malignant SPNs. Method : 34 patients with a solitary pulmonary nodule less than 6 cm of irs diameter who visited Samsung Medical Center from Semptember, 1994 to Semptember, 1995 were evaluated prospectively. Simple chest roentgenography, chest computer tomography, FOG-PET scan were performed for all patients. The results of FOG-PET were evaluated comparing with the results of final diagnosis confirmed by sputum study, PCNA, fiberoptic bronchoscopy, or thoracotomy. Results : (I) There was no significant difference in nodule size between malignant (3.1 1.5cm) and benign nodule(2.81.0cm)(p>0.05). (2) Peal SUV(standardized uptake value) of malignant nodules (6.93.7) was significantly higher than peak SUV of benign nodules(2.71.7) and time-activity curves showed continuous increase in malignant nodules. (3) Three false negative cases were found among eighteen malignant nodule by the FDG-PET imaging study and all three cases were nonmucinous bronchioloalveolar carcinoma less than 2 em diameter. (4) FOG-PET imaging resulted in 83% sensitivity, 100% specificity, 100% positive predictive value and 84% negative predictive value. Conclusion: FOG-PET imaging is a new noninvasive diagnostic method of solitary pulmonary nodule thai has a high accuracy of differential diagnosis between malignant and benign nodule. FDG-PET imaging could be used for the differential diagnosis of SPN which is not properly diagnosed with conventional methods before thoracotomy. Considering the high accuracy of FDG-PET imaging, this procedure may play an important role in making the dicision to perform thoracotomy in diffcult cases.

• The Korean Journal of Air & Space Law and Policy
• /
• v.32 no.2
• /
• pp.101-127
• /
• 2017

Even with the most advanced aviation technology benefits, aircraft accidents are constantly occurring while air passenger transportation volume is expected to double in the next 15 years. Since it is not possible to secure aviation safety only by the post aircraft accident safety action of accident investigations, it has been recognized and consensus has been formed that proactive and predictive prevention measures are necessary. In this sense, the aviation safety management system (SMS) was introduced in 2008 and has been carried out in earnest since 2011. SMS is a proactive and predictive aircraft accident preventive measure, which is a mechanism to eliminate the fundamental risk factors by approaching organizational factors beyond technological factors and human factors related to aviation safety. The methodology is to collect hazards in all the sites required for aircraft operations, to build a database, to analyze the risks, and through managing risks, to keep the risks acceptable or below. Therefore, the improper implementation of SMS indicates that the aircraft accident prevention is insufficient and it is to be directly connected with the aircraft accident. Reports of duty performance related hazards including their own errors are essential and most important in SMS. Under the policy of just culture for voluntary reporting, the guarantee of information providers' anonymity, non-punishment and non-blame should be basically secured, but to this end, under-reporting is stagnant due to lack of trust in their own organizations. It is necessary for the accountable executive(CEO) and senior management to take a leading role to foster the safety culture initiating from just culture with the safety consciousness, balancing between safety and profit for the organization. Though a Ministry of Land, Infrastructure and Transport's order, "Guidance on SMS Implementation" states the training required for the accountable executive(CEO) and senior management, it is not legally binding. Thus it is suggested that the SMS training completion certificates of accountable executive(CEO) and senior management be included in SMS approval application form that is legally required by "Korea Aviation Safety Program" in addition to other required documents such as a copy of SMS manual. Also, SMS related items are missing in the aircraft accident investigation, so that organizational factors in association with safety culture and risk management are not being investigated. This hinders from preventing future accidents, as the root cause cannot be identified. The Aircraft Accident Investigation Manuals issued by ICAO contain the SMS investigation wheres it is not included in the final report form of Annex 13 to the Convention on International Civil Aviation. In addition, the US National Transportation Safety Board(NTSB) that has been a substantial example of the aircraft accident investigation for the other accident investigation agencies worldwide does not appear to expand the scope of investigation activities further to SMS. For these reasons, it is believed that investigation agencies conducting their investigations under Annex 13 do not include SMS in the investigation items, and the aircraft accident investigators are hardly exposed to SMS investigation methods or techniques. In this respect, it is necessary to include the SMS investigation in the organization and management information of the final report format of Annex 13. In Korea as well, in the same manner, SMS item should be added to the final report format of the Operating Regulation of the Aircraft and Railway Accident Investigation Board. If such legal and institutional improvement methods are complemented, SMS will serve the purpose of aircraft accident prevention effectively and contribute to the improvement of aviation safety in the future.

• 한국사회복지학회:학술대회논문집
• /
• 2003.10a
• /
• pp.185-216
• /
• 2003

This study was aimed at investigating important factors influencing career success among regular workers. The current researcher scrutinized the degree to which variables and factors affect the career success and occupational turnover rates of the research participants. At the same tune, two hypothetical path models established by the researcher were examined using linear multiple regression methods and the LISREL. After examining the differences among the factors of career success, a comparison was made between the disabled worker group and the non-disabled worker group. A questionnaire using the 5-point Likert scale was distributed to a group of 374 workers with disabilities and 463 workers without disabilities. For the data analysis purpose, the structural equation model, factor analysis, correlation analysis, and multiple regression analysis were carried out. The results of this study ran be summarized as follows. First, the results of factor analysis showed important categories of conceptual themes of career success. The initial conceptual factor model did not accord with the empirical one. A three-factorial model revealed categories of personal, family, and organizational factor respectively. The personal factor was composed of the self-esteem and self-efficiency. The family factor was consisted of the multi-roles stress and the number of children. Finally, the organizational factor was composed of the capacity for utilizing resources, networking, and the frequency of mentoring. In addition, the total 10 sub areas of career success were divided by two important aspects; the subjective career success and the objective career success. Second, both research participant groups seemed to be influenced by their occupational types. However, all predictive variables excluding the wage rate and the average length of work years had significant impact on job success for the disabled work group, while all the variables excluding the frequency of advice and length of working years had significant impact on job success for the non-disabled worker group. Third, the turnover rate was significantly influenced by the age and the experience of turnover of the research participants. However, the number of co-workers was the strongest predictive variable for the worker group with disabilities, but the occupation choice variable for the worker group without disabilities. For the disabled worker group, the turnover rate was differently influenced by the type of occupation, the length of working years, while multi-role stress and the average working years at the time of turnover for the worker group without disabilities. Fifth, as a result of verifying the hypothetical path model, it showed that the first model was somewhat proper and could predict the career success on both research participant groups. In the second model, the Chi-square, the degree of freedom (($x^2=64.950$, df=61, P=0.341), and the adjusted Goodness of Fit Index (AGFI) were .964, and the Comparative Fit Index (CFI) were .997, and the Root Mean Squared Residual (RMR) was respectively. .038. The model was best fitted and could predict the career success more highly because the goodness of fit index in the whole models was within the allowed range. In conclusion, the following research implications can be suggested. First, the occupational type of research participants was one of the most important variables to predict the career success for both research participant groups. It means that people with disabilities require human development services including education. They need to improve themselves in this knowledge-based society. Furthermore, for maintaining the career success, people with disabilities should be approached by considering the subjective career success aspects including wages and the promotion opportunities than the objective career success aspects.

• Journal of Gastric Cancer
• /
• v.9 no.3
• /
• pp.96-103
• /
• 2009

Purpose: Lymph node metastasis is an important factor in determining prognosis and therapeutic options for early gastric cancer (EGC) patients. Vascular endothelial growth factor (VEGF)-C and D are known as lymphangiogenic factors, and cyclooxygenase (COX)-2 is thought to play a role in lymph node metastasis in gastric carcinoma. This study was designed to determine whether the expression of VEGF-C, VEGF-D, and COX-2 is associated with clinicopathologic factors, especially lymph node metastasis in EGCs invading the submucosa. Materials and Methods: Tissue samples were obtained from 85 Patients undergoing standard gastrectomy with lymph node dissection between 1991 and 2007 in the Department of Surgery of Daejeon St. Mary's Hospital in Daejeon, Korea. All patients were diagnosed with gastric cancers and submucosal invasion. We examined the expression of VEGF-C, VEGF-D, and COX-2 using immunohistochemical methods. Results: Of the 85 patients, 16 (18.8%) had lymph node metastasis. VEGF-C, VEGF-D, and COX-2 were positively expressed in 34.1% (29/85), 22.3% (19/85), and 37.6% (32/85) of the patients. VEGF-C and COX-2 expression was significantly correlated with lymph node metastasis (P<0.05). A positive correlation existed between VEGF-C and COX-2 expression (P< 0.001). Conclusion: VEGF-C and COX-2 expression is associated with lymph node metastasis in gastric cancer with submucosal invasion. VEGF-C and COX-2 may thus be predictive markers for lymph node metastasis in EGC patients with submucosal invasion.