• The korean journal of orthodontics
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• v.34 no.5 s.106
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• pp.371-379
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• 2004

The purpose of this study was to investigate the changes and types of statistical methods used in the Korean Journal of Orthodontics (KJO) and the American Journal of Orthodontics and Dentofacial Orthopedics (AJODO) from )999 to 2003. The frequency of use, transitions, assumption check of statistical methods and types of advanced statistical methods were examined from each journal. The study consisted of 247 articles published in the KJO and randomly chosen 50 articles per year which were original articles and used statistical methods T-test, analysis of variance(ANOVA), correlation analysis, nonparametric analysis. regression analysis chi-square test. factor analysis, were the order of statistical methods most frequently used in the KJO, while t-test. ANOVA, nonparametric analysis, correlation analysis, regression analysis, chi-square test. factor analysis. were the order of statistical methods used in the AJODO The changes of statistical methods observed in the KJO were not significant $(X^2=17.4\;p=0.5881)$ but the changes observed in the AJODO was seen to be significant $(x^2=42.4,\;p=0.0397)$ Some of the studies examined had overlooked the assumptions of the statistical methods employed. Data investigation such as outlier should be performed before analysis and alternative statistical approaches are applied for a small sample size. Types of advanced statistical methods were factor analysis and discriminant analysis in the KJO and Intention-To-Treat (ITT) analysis in clinical trials through multi-center, survival analysis and Generalized Estimating Equations (GEE) in the AJODO. Appropriate analysis approaches and interpretations should be applied for the correlated and repeated measurements of the orthodontic data set.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.10 no.2
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• pp.212-219
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• 1999

Objective：This study is designed to get clinical guidelines for management of children with TBI by examining neuropsychiatric sequelae of TBI, determining whether the severity of TBI, type of treatment, and enviornmental factors are related to those sequelae, and defining the adequacy of public psychological tests as evaluating tools for them. Method：This is chart review of 47 children, aged 5 to 14 years, referred to a psychiatric outpatient clinic for neuropsychiatric evaluation at least 6 months after TBI. Data on the initial GCS score, associated injury, treatment type, and duration of hospital stay are obtained from medical records. EEG, MRI, intelligent test, and several psychological tests are administrated at the point of assessment. Results：1) Cognitive symptoms outnumber externalizing behavioral, emotional, and somatic symptoms, with no significant differences of frequencies of those 4 categorical symptoms between mild injury group and moderate to severe group. 2) Children treated with non-surgical method(p<0.01) complain more cognitive symptoms than the others. 3) Behavioral symptoms are related to younger age(p<0.05), and to anticonvulsant medication(p<0.05). 4) Children with associated injury complain emotional symptoms more frequently(p<0.05). 5) More somatic symptoms are presented by children with no medication(p<0.05), and with higher I.Q(p<0.05). 6) Low I.Q is correlated to low GCS score (p<0.05). Cognitive impairment is confirmed in 25 in 42 children complaining cognitive symptoms though I.Q test and BGT, whose hospital stay is longer than the others(p<0.05). 7) emotional disturbance is confirmed in 22 in 25 children showing emotional problems through psychological tests, who complain cognitive symptoms more frequently(p<0.05). Conclusion：This findings suggest that even mild TBI children need to be followed-up and treated as complaining neuropsychiatric symptoms over 6 months after injury, and shorter hospital stay is recommended for cognitive and emotional status of children, and for better evaluation of neuropsychiatric sequelae of TBI, more specific tests should be included in neuropsychological test tools.

• Tuberculosis and Respiratory Diseases
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• v.49 no.6
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• pp.733-739
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• 2000

Background : Pleural eosinophilia is rare and commonly considered to be an indicator of good prognosis. The diagnostic significance of eosinophilic pleural effusions remains controversial despite a century of observation and discussion. This study was conducted to assess the prevalence of eosinophilia in 446 consecutive samples of pleural fluid, to review the cause of eosinophilic pleural effusion and to determine whether the presence of eosinophils increases the likehood of benign conditions. Method : A retrospective analysis was performed upon patients that underwent first thoracentesis due to pleural effusion between January 1999 and December 1999. Results : Eosinophilic pleural effusions were identified in 24 of the 446 patients (5.4%). Malignancy, parapneumonic effusion and tuberculosis were determined the major causes of pleural effusion (80.6%). Malignancy was diagnosed as frequently in eosinophilic effusions as in non-eosinophilic effusions (54.2% vs 50.5%, p=0.725). No difference was found in the prevalence of eosinophilic and non-eosinophilic effusion according to the etiology. The mean blood eosinophil ratio in patients with eosinophilic pleural effusion was 5.4% and no significant correlation existed between the blood and pleural eosinophilic count. Conclusion : Pleural eosinophilia is not helpful for differentiating benign and malignant etiology and is not related with bood eosinophilia or repeated tapping.

• Tuberculosis and Respiratory Diseases
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• v.63 no.1
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• pp.59-66
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• 2007

Background: Surgical lung biopsy is required to establish the etiology and stage of interstitial lung disease(ILD). and this procedure can be safe and meaningful for making clinical decisions. We wanted to determine the safety of surgical lung biopsy(SLB) in patients with interstitial lung disease(ILD). Methods: We conducted a retrospective review of 40 patients with suspected ILD and they underwent surgical lung biopsy from January 2001 to June 2006 at Chungnam University Hospital. We analyzed retrospectively according to their age, gender, pulmonary function, chest tube duration, the arterial blood gases, the procedural technique, and the requirement for supplemental oxygen and mechanical ventilation(MV) at the time of SLB. Results: The mean age of the patients was 56.4${\pm}$16.13 years(range: 21 to 77 years). Overall, the 30-day and 90-day mortality rates were 15% and 20%, respectively. The predictors of perioperative mortality were either the need for mechanical ventilation(MV) at the time of SLB or the need for supplemental oxygen prior to undergoing SLB. Among the 32 patients who were 90-day survivors, the proportion of those patients using the oxygen supplement was 28.1% (n=9). All 8 patients who were 90-day non-survivors used oxygen supplement (p=0.000). The use of the MV was 12.5% (n=4) in the 90-day survivors (n=32) and 62.5% (n=5) in the 90-day non-survivors (n=8); there was a significant difference between the 90-day survivors and non-survivors (p=0.000). Conclusion: Patients who require MV and supplemental oxygen are associated with an increased risk for death following SLB.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.2
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• pp.172-180
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• 2007

Among the nuclear medicine imaging methods available today, $H_2^{15}O-PET$ is most widely used by cognitive neuroscientists to examine regional brain function via the measurement of regional cerebral blood flow (rCBF). The short half-life of the radioactively labeled probe, $^{15}O$, often allows repeated measures from the same subjects in many different task conditions. $H_2^{15}O-$ PET, however, has technical limitations relative to other methods of functional neuroimaging, e.g., fMRI, including relatively poor time and spatial resolutions, and, frequently, insufficient statistical power for analysis of individual subjects. However, recent technical developments, such as the 3-D acquisition method provide relatively good image quality with a smaller radioactive dosage, which in turn results in more PET scans from each individual, thus providing sufficient statistical power for the analysis of individual subject's data. Furthermore, the noise free scanner environment $H_2^{15}O$ PET, along with discrete acquisition of data for each task condition, are important advantages of PET over other functional imaging methods regarding studying state-dependent changes in brain activity. This review presents both the limitations and advantages of $^{15}O-PET$, and outlines the design of efficient PET protocols, using examples of recent PET studies both in the normal healthy population, and in the clinical population.

• Journal of Chest Surgery
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• v.39 no.3 s.260
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• pp.220-225
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• 2006

Background: Spontaneous pneumomediastinum is an uncommon, benign, self-limited disorders that usually occurs in young adults without any apparent precipitating factors or disease. The purpose of this study was to review our experience in dealing with this entity and describe a reasonable course of assessment and management. Material and Method: A retrospective case series was conducted to identify adults patients with SPM who were diagnosed and treated in a single institution between 2001 and 2005. Result: Fifteen patients were identified who included 14 men and 1 women with a mean age of 26 years. Presenting symptoms were chest pain in 12 patients ($80\%$), dyspnea in 5 patients ($33\%$), and throat discomfort in 4 patients ($26\%$). Two cases were associated with use of inhalational drugs and 3 cases were associated with exercise. The predisposing factors were asthma, excessive exercise, and vomiting in spontaneous pneumomediastinum. The physical findings were subcutaneous emphysema in 10 patients ($77\%$). Chest radiography and computerized tomography were the diagnostic methods in all cases with CT scan revealing six cases with associated pulmonary abnormalities. Esophagogram and flexible bronchoscopy were selectively used. Fifteen patients ($100\%$) were admitted to the hospital. Their mean hospital stay was 3 days. All patients were conservatively treated. In a follow-up of 3 years no complications or recurrences were observed. Conclusion: Most simple spontaneous pneumomediastinum cases were benign diseases and most of them ($77\%$) had shown typical chest pain, dyspnea and subcutaneous emphysema. Inhalational drug use was not a major cause of SPM; however, increased use of bronchoinhalers was a suspicious cause of SPM.

• Journal of Chest Surgery
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• v.32 no.3
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• pp.237-248
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• 1999

Background: The late results of repair of tetralogy of Fallot(TOF) are favorable in most patients. Some portion of the patients with tetralogy, however, require reoperation for residual lesions or result in late death. The outcome of patients after tetralogy repair performed during the past 13 years was studied, with an emphasis on postrepair survival and problems including reoperations. Material and Method: A retrospective review of clinical, echocardiographic and catheterization data was performed in 569 of 775 patients with TOF who underwent corrective repair between 1983 and 1995 at Sejong General Hospital, Buchon, Korea. Result: Of 28(4.9%) early deaths(defined as 30 days postrepair), 12 deaths(42.9%) were <1 year of age, with an operative mortality of 15.4%. The surviving 541 patients(age 2.8 months to 43.4 years, median 23 months) have been followed up from 1 month to 12.6 years(median 35 months) postoperatively. Most patients were in good functional class and had normal right ventricular(RV) function. Postrepair results were compared between the transatrial-transpulmonary approach and the conventional right ventriculotomy. The former technique provided a lesser incidence of significant pulmonary regurgitation(P<0.001) and alesser degree of RV dysfunction(P<0.05) compared with those in the latter. There were 10(1.8%) late deaths during the follow-up period and 6 of the deaths were directly related to reoperation or ventricular dysfunction. The 10-year actuarial survival rate was 96.7%. There were 44 reoperations(8.1%) in 39 patients(7.2%), with an operative mortality of 10.3%. The main indications or reoperation included residual ventricular septal defect(VSD) (n=6), pulmonary stenosis(PS) (n=11), VSD with PS(n=17), pulmonary regurgitation(n=7), and tricuspid regurgitation(n=2). The 5- and 10-year freedom from reoperation were 89.4% and 76.1%, respectively. Conclusion: Although the majority of patients with repaired TOF are clinically well, with a high rate of survival, approximately 7% of patients have residual lesions that require surgical therapy. Therefore, the timely and meticulous corrective repair is mandatory to avoid reoperation, and continued close surveillance is also needed for the early detection of residual problems.

• Journal of Chest Surgery
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• v.34 no.12
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• pp.909-916
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• 2001

Background : Varicose vein is a very common vascular disease and has recently become a matter of concern for thoracic and cardiovascular surgens. Material and Method : We analyzed 209 cases or 269 feet with varicose vein retrospectively, which had been treated in our hospital from April 1999 to December 2000. Result : Male : Female ratio was 1:3(Male : 52 cases, Female : 157 cases), mean age was 42.2$\pm$9.7 years old, mean duration of varicosities was 12.2$\pm$9.7 years, and mean follow up was 14.8$\pm$6.1 months from July 2001. Most common symptom was leg pain(122 cases, 58.4%). Long standing job(44 cases), pregnancy(37 cases), and family history related to varicose vein came to 79.9% as the major predisposing or precipitating factors. Anatomic classifications of main lesion were GSV (greater saphenous vein,126 cases), LSV(lesser saphenous vein,18 cases), and reticular veins and telangiectasias(65 cases). Main treatments were stripping of GSV, stab avulsion, ligation of saphenofemoral junction, sclerotherapy, and conservative treatment. Comparing A group (stripping of GSV) with B group(sclerotherapy of GSV), A group had more complications than B group; however, A group had less recurrences than B group(p 0.05). Comparing C group(stab avulsion of LSV) with D group(sclerotherapy of LSV), there were 2 cases of recurrence in D group; however, there were no statistical differences between the two groups in complication and recurrence(p>0.05). Comparing B group(sclerotherapy of GSV) with E group(sclerotherapy of reticular vein and telangiectasia), there were no differences in complication; however, B group had more recurrences than E group. Post-stripping complications were ankle numbness and tingling(2 cases), ankle pain(2 cases),ankle swelling(2 cases), and wound pain(1 case). Postsclerotherapy complications were thrombophlebitis(1 case) and skin ulcer(1 case). Conclusion: Sclerotherapy for varicose vein involving GSV had more recurrences than stripping for lesions involving GSV. Sclerotherapy for reticular vein and telangiectasia had less recurrences than sclerotherapy for lesion involving GSV. Sclerotherapy is a very convenient method without operation and admission, thus further research is demanded in case of varicose vein involving GSV.

• The Korean Journal of Nuclear Medicine
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• v.36 no.6
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• pp.344-356
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• 2002

Purpose: RBC blood pool SPECT has been used to diagnose focal liver lesion such as hemangioma owing to its high specificity. However, low spatial resolution is a major limitation of this modality. Recently, ordered subset expectation maximization (OSEM) has been introduced to obtain tomographic images for clinical application. We compared this new modified iterative reconstruction method, OSEM with conventional filtered back projection (FBP) in imaging of liver hemangioma. Materials and Methods: Sixty four projection data were acquired using dual head gamma camera in 28 lesions of 24 patients with cavernous hemangioma of liver and these raw data were transferred to LINUX based personal computer. After the replacement of header file as interfile, OSEM was performed under various conditions of subsets (1,2,4,8,16, and 32) and iteration numbers (1,2,4,8, and 16) to obtain the best setting for liver imaging. The best condition for imaging in our investigation was considered to be 4 iterations and 16 subsets. After then, all the images were processed by both FBP and OSEM. Three experts reviewed these images without any information. Results: According to blind review of 28 lesions, OSEM images revealed at least same or better image quality than those of FBP in nearly all cases. Although there showed no significant difference in detection of large lesions more than 3 cm, 5 lesions with 1.5 to 3 cm in diameter were detected by OSEM only. However, both techniques failed to depict 4 cases of small lesions less than 1.5 cm. Conclusion: OSEM revealed better contrast and define in depiction of liver hemangioma as well as higher sensitivity in detection of small lesions. Furthermore this reconstruction method dose not require high performance computer system or long reconstruction time, therefore OSEM is supposed to be good method that can be applied to RBC blood pool SPECT for the diagnosis of liver hemangioma.

• Journal of Korean Society of Spine Surgery
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• v.25 no.4
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• pp.147-153
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• 2018

Study Design: Retrospective case series. Objectives: We retrospectively evaluated the clinical efficacy of postganglionic nerve block in symptomatic Schmorl nodules (SNs). Summary of Literature Review: SNs are common lesions that are often asymptomatic. In certain cases, SNs have been reported to cause severe axial back pain, thereby considerably impacting patients' quality of life. No consensus currently exists on the treatment of symptomatic SNs. Materials and Methods: From October 2015 to October 2017, a total of 21 patients with symptomatic SNs diagnosed by magnetic resonance imaging (MRI) that did not respond to conservative treatment after 4 weeks were included in the study. All patients received postganglionic nerve block. We evaluated effective pain relief (improvement of back pain of more than 50% compared with before the intervention) and functional improvements, assessed by visual analogue scale (VAS) and Oswestry Disability Index scores obtained at 4 hours, 4 weeks, 8 weeks, 3 months, and 6 months after the procedure. Results: Symptomatic SNs were more common at the L2-3 level, and the lower end plate was more commonly involved than the upper end plate. Eighteen of the 21 patients (85.7%) showed effective pain relief, and no deterioration was observed within the followup period. Throughout the follow-up period, the VAS remained significantly improved compared to before the procedure (p<0.05). Complications were not reported in any cases. Conclusions: Postganglionic nerve block for symptomatic SNs that do not respond to conservative treatment is a non-invasive modality for pain relief.