• Korean Journal of Radiology
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• v.24 no.9
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• pp.827-837
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• 2023

Objective: To investigate the predictive value of radiomics features based on cardiac magnetic resonance (CMR) cine images for left ventricular adverse remodeling (LVAR) after acute ST-segment elevation myocardial infarction (STEMI). Materials and Methods: We conducted a retrospective, single-center, cohort study involving 244 patients (random-split into 170 and 74 for training and testing, respectively) having an acute STEMI (88.5% males, 57.0 ± 10.3 years of age) who underwent CMR examination at one week and six months after percutaneous coronary intervention. LVAR was defined as a 20% increase in left ventricular end-diastolic volume 6 months after acute STEMI. Radiomics features were extracted from the oneweek CMR cine images using the least absolute shrinkage and selection operator regression (LASSO) analysis. The predictive performance of the selected features was evaluated using receiver operating characteristic curve analysis and the area under the curve (AUC). Results: Nine radiomics features with non-zero coefficients were included in the LASSO regression of the radiomics score (RAD score). Infarct size (odds ratio [OR]: 1.04 (1.00-1.07); P = 0.031) and RAD score (OR: 3.43 (2.34-5.28); P < 0.001) were independent predictors of LVAR. The RAD score predicted LVAR, with an AUC (95% confidence interval [CI]) of 0.82 (0.75-0.89) in the training set and 0.75 (0.62-0.89) in the testing set. Combining the RAD score with infarct size yielded favorable performance in predicting LVAR, with an AUC of 0.84 (0.72-0.95). Moreover, the addition of the RAD score to the left ventricular ejection fraction (LVEF) significantly increased the AUC from 0.68 (0.52-0.84) to 0.82 (0.70-0.93) (P = 0.018), which was also comparable to the prediction provided by the combined microvascular obstruction, infarct size, and LVEF with an AUC of 0.79 (0.65-0.94) (P = 0.727). Conclusion: Radiomics analysis using non-contrast cine CMR can predict LVAR after STEMI independently and incrementally to LVEF and may provide an alternative to traditional CMR parameters.

• The korean journal of orthodontics
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• v.54 no.2
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• pp.79-88
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• 2024

Objective: Alveolar bone loss is a common adverse effect of intrusion treatment. Mandibular incisors are prone to dehiscence and fenestrations as they suffer from thinner alveolar bone thickness. Methods: Thirty skeletal class II patients treated with mandibular intrusion arch therapy were included in this study. Lateral cephalograms and cone-beam computed tomography images were taken before treatment (T1) and immediately after intrusion arch removal (T2) to evaluate the tooth displacement and the alveolar bone changes. Pearson's and Spearman's correlation was used to identify risk factors of alveolar bone loss during the intrusion treatment. Results: Deep overbite was successfully corrected (P < 0.05), accompanied by mandibular incisor proclination (P < 0.05). There were no statistically significant change in the true incisor intrusion (P > 0.05). The labial and lingual vertical alveolar bone levels showed a significant decrease (P < 0.05). The alveolar bone is thinning in the labial crestal area and lingual apical area (P < 0.05); accompanied by thickening in the labial apical area (P < 0.05). Proclined incisors, non-extraction treatment, and increased A point-nasion-B point (ANB) degree were positively correlated with alveolar bone loss. Conclusions: While the mandibular intrusion arch effectively corrected the deep overbite, it did cause some unwanted incisor labial tipping/flaring. During the intrusion treatment, the alveolar bone underwent corresponding changes, which was thinning in the labial crestal area and thickening in the labial apical area vice versa. And increased axis change of incisors, non-extraction treatment, and increased ANB were identified as risk factors for alveolar bone loss in patients with mandibular intrusion therapy.

• Journal of The Korean Society of Clinical Toxicology
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• v.21 no.2
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• pp.69-80
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• 2023

Purpose: Suicide ranks among the top causes of death among youth in South Korea. This study aimed to identify the characteristics of suicidal individuals treated at emergency departments between 2011 and 2020. Methods: A retrospective analysis was conducted using data from January 2011 to December 2020 in the Injury Surveillance Cohort, a prospective registry. Patients' sex, age, mortality, methods of self-harm, and previous suicide attempts were analyzed. The methods of self-harm were categorized into falls, asphyxiation, blunt injuries, penetrating injuries, poisoning, and others. Sub-groups with and without poisoning were compared. Results: The proportion of self-harm/suicide attempts increased from 2.3% (2011) to 5.0% (2020). The mortality rate decreased from 10.8% (2011) to 6.3% (2020). Poisoning was the most common method (61.7%). Mortality rates ranged from 42.0% for asphyxiation to 0.2% for blunt injuries. Individuals in their 20s showed a marked increase in suicide/self-harm attempts, especially in the last three years. A large proportion of decedents in their 70s or older (52.6%) used poisoning as a method of suicide. The percentage of individuals with two or more previous attempts rose from 7.1% (2011) to 19.7% (2020). The death rates by poisoning decreased from 7.7% (2011) to 2.5% (2020). Conclusion: Our findings underscore the urgent need for targeted interventions and suicide prevention policies. Managing and reducing suicide and self-harm in emergency settings will require a focus on poisoning, the 10-29 age group, and the elderly. This paper will be valuable for future policies aiming to reduce the societal burden of suicide and self-harm.

• Korean Journal of Radiology
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• v.22 no.2
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• pp.253-262
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• 2021

Objective: To determine whether the values of hepatic apparent diffusion coefficient (ADC) can differentiate biliary atresia (BA) from non-BA or be correlated with the grade of hepatic fibrosis in infants with cholestasis. Materials and Methods: This retrospective cohort study included infants who received liver MRI examinations to evaluate cholestasis from July 2009 to October 2017. Liver ADC, ADC ratio of liver/spleen, aspartate aminotransferase to platelet ratio index (APRI), and spleen size were compared between the BA and non-BA groups. The diagnostic performances of all parameters for significant fibrosis (F3-4) were obtained by receiver-operating characteristics (ROCs) curve analysis. Results: Altogether, 227 infants (98 males and 129 females, mean age = 57.2 ± 36.3 days) including 125 BA patients were analyzed. The absolute ADC difference between two reviewers was 0.10 mm²/s for both liver and spleen. Liver ADC value was specific (80.4%) and ADC ratio was sensitive (88.0%) for the diagnosis of BA with comparable performance. There were 33 patients with F0, 15 with F1, 71 with F2, 35 with F3, and 11 with F4. All four parameters of APRI (τ = 0.296), spleen size (τ = 0.312), liver ADC (τ = -0.206), and ADC ratio (τ = -0.288) showed significant correlation with fibrosis grade (all, p < 0.001). The cutoff values for significant fibrosis (F3-4) were 0.783 for APRI (area under the ROC curve [AUC], 0.721), 5.9 cm for spleen size (AUC, 0.719), 1.044 x 10^-3 mm²/s for liver ADC (AUC, 0.673), and 1.22 for ADC ratio (AUC, 0.651). Conclusion: Liver ADC values and ADC ratio of liver/spleen showed limited additional diagnostic performance for differentiating BA from non-BA and predicting significant hepatic fibrosis in infants with cholestasis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.105-114
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• 2017

The purpose of this study was to examine the effects of obesity at diagnosis on the prognosis of Korean breast cancer patients after classifying them according to their reproductive history and age by comparing the overall survival rate (OS) and disease-free survival rate (DFS). This study is a retrospective cohort study using 4181 breast cancer cases at one of the medical centers in Korea during the 3 year period from 2006 to 2008. We confirmed the levels of death and recurrence through a follow-up study completed in May 30. 2015. In conclusion, the parous patients had a lower OS than the non-parous patients (p=.000), and the younger patients below 40 years old had a lower OS and DFS than those who were 40 years old or older (p=.003, p=.000), while obesity did not affect the OS and DFS significantly. However, several subgroups in which obesity affected the OS and DFS were found after classifying the patients according to their reproductive history and age. For the subgroups classified by reproductive history, the obese patients had a lower OS and DFS than the non-obese patients in the subgroup in which the patients have a reproductive history (p=.001, p=.005). For the subgroups classified according to age, the obese patients had a lower OS and DFS than the non-obese patients in the subgroup in which the patients were 40 years old or older (p=.005, p=.014). Obesity affected the OS and DFS in the subgroup in which the patients were 40 years old or older and had a reproductive history (p=.000, p=.003). The results of this study show that obesity has an effect on the prognosis of breast cancer patients in the subgroups classified by reproductive history and age, whereas it has no effect on the OS and DFS of the patients when they are examined in their entirety. It also suggests that appropriate nursing intervention is needed for the subgroups in which obesity has effects on prognosis.

• Tuberculosis and Respiratory Diseases
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• v.83 no.1
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• pp.31-41
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• 2020

Background: Chronic cough is defined as a cough lasting more than 8 weeks and socio-economic burden of chronic cough is enormous. The characteristics of chronic cough in Korea are not well understood. The Korean Academy of Tuberculosis and Respiratory Diseases (KATRD) published guidelines on cough management in 2014. The current study evaluated the clinical characteristics of chronic cough in Korea and the efficacy of the KATRD guidelines. Methods: This was a multi-center, retrospective observational study conducted in Korea. The participants were over 18 years of age. They had coughs lasting more than 8 weeks. Subjects with current pulmonary diseases, smokers, exsmokers with more than 10 pack-years or who quit within the past 1 year, pregnant women, and users of cough-inducing medications were excluded. Evaluation and management of cough followed the KATRD cough-management guidelines. Results: Participants with chronic cough in Korea showed age in the late forties and cough duration of more than 1 year. Upper airway cough syndrome was the most common cause of cough, followed by cough-variant asthma (CVA). Gastro-esophageal reflux diseases and eosinophilic bronchitis were less frequently observed. Following the KATRD cough-management guidelines, 91.2% of the subjects improved after 4 weeks of treatment. Responders were younger, had a longer duration of cough, and an initial impression of CVA. In univariate and multivariate analyses, an initial impression of CVA was the only factor related to better treatment response. Conclusion: The causes of chronic cough in Korea differed from those reported in other countries. The current Korean guidelines proved efficient for treating Korean patients with chronic cough.

• Tuberculosis and Respiratory Diseases
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• v.45 no.6
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• pp.1154-1166
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• 1998

Background : In the management of patients whose primary chemotherapy has failed, careful assessment is essential. It is important to find out as accurate a chemotherapy history as possible. Preferably it should contain the drugs which has never used before. The purpose of present study is establishment of retreatment regimen for pulmonary tuberculosis. The present report concerns the results of retreatment of pulmonary tuberculosis patients treated at National Masan Tuberculosis Hospital. Methods : Retrospective cohort study was made of 104 drug-resistant pulmonary tuberculosis patients who were treated by five regimens between Jan. 1994 and Nov. 1996. All the patients taken medicine for second anti-tuberculosis regimens for the first time. We separated the patients by three groups(Group I ; OFX+PTA+CS+PAS+Aminoglycoside, Group II : PZA+PTA+CS+PAS+Aminoglycoside, Group III : PZA+OFX+PTA+PAS+Aminoglycoside). Results : The age distribution was most frequent in fourth decade(36patients, 34.6%) and the mean age was 42.6 year. The sex distribution was more frequent in the males(81 patients, 85.7%). There was 31 patients(29.8%) with combined diseaes, 18 patients with complication and 24 patients(27.9%) with family history. Primary chemotherapy regimens were HERZ(S or K) in 48 patients (46.2%), HER(S or K) in 41 patients(39.4%) and others in 15 patients(14.4%). Result of drug sensitivity test showed that the resistance to INH and RFP is in 68 patients(65.4%), RFP is 12 patients(11.5%), INH is in 3 patients(2.9%) and all sensitive to INH and RFP is 3 patients(2.9%). The clinical symptoms on admission were coughing(89.4%), sputum(69.2%), dyspnea on exertion(37.5%), weight loss(33.7%) blood tinged sputum(15.4%) and others. The extent of disease on the radiograph was far-advanced in 73 patients(70.2%), moderate in 28 patients(26.9%) and minimal in 3 patients(2.9%). The side effects for drugs were gastrointestinal troubles in 31 patients(29.8%), arthralgia in 22 patients(21.2%), skin rash in 12 patients(11.5%) and others. The negative conversion rate on sputum AFB smear was 85.6%(87.5% in Group I, 80.0% in Group II and 90.5% in Group III). The average negative conversion time on sputum was 4 month(4.0 month in Group I, 4.6 month in Group II and 3.0 month in Group III). Conclusion : In the retreatment of pulmonary tuberculosis, ofloxacin is useful drug for the patients who are not available to use PZA and combination of PZA and OFX can be use effectively substituting for CS.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.19 no.1
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• pp.1-11
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• 2019

Purpose: Congenital hypothyroidism (CH) is the most common congenital endocrine disorder. The purpose of the present study was to determine the incidence of CH in South Korea during the period from January 1991 to March 2004. Methods: Central data from each city branch of SCL (Seoul Clinical Reference Laboratories) in Yongin, South Korea, was gathered and collectively analyzed. Newborn screening (NBS) for CH was based on measuring the levels of neonatal thyroid stimulating hormone (TSH) and free T4 (a cut-off of 20 mIU/L and less than 0.8 ng/dL, respectively). Results: During the study period, 671,805 live births were screened for CH based on TSH and free T4 ELISA assays. A total of 159 newborns were deemed positive for CH out of 671,805, with a corresponding incidence of 1 in 4,225. When a cut-off of 20 mIU/L was used in TSH assays, the associated sensitivity, specificity, and positive predictive values (PPV) were 100.0%, 99.7%, and 10.8%, respectively. When a cut-off of 0.8 ng/dL in free T4 assays was used, the associated sensitivity, specificity, and PPV were 100.0%, 98.5%, and 3.9%, respectively. Conclusion: CH incidence in South Korea as evidenced by the results of NBS was compared with its incidence and comparable to the other countries prior to 2004.

• Journal of Gastric Cancer
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• v.20 no.2
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• pp.152-164
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• 2020

Purpose: To compare long-term disease-free survival (DFS) between patients receiving tegafur/gimeracil/oteracil (S-1) or capecitabine plus oxaliplatin (CAPOX) adjuvant chemotherapy (AC) for gastric cancer (GC). Materials and Methods: This retrospective multicenter observational study enrolled 983 patients who underwent curative gastrectomy with consecutive AC with S-1 or CAPOX for stage II or III GC at 27 hospitals in Korea between February 2012 and December 2013. We conducted propensity score matching to reduce selection bias. Long-term oncologic outcomes, including DFS rate over 5 years (over-5yr DFS), were analyzed postoperatively. Results: The median and longest follow-up period were 59.0 and 87.6 months, respectively. DFS rate did not differ between patients who received S-1 and CAPOX for pathologic stage II (P=0.677) and stage III (P=0.899) GC. Moreover, hazard ratio (HR) for recurrence did not differ significantly between S-1 and CAPOX (reference) in stage II (HR, 1.846; 95% confidence interval [CI], 0.693-4.919; P=0.220) and stage III (HR, 0.942; 95% CI, 0.664-1.337; P=0.738) GC. After adjustment for significance in multivariate analysis, pT (4 vs. 1) (HR, 11.667; 95% CI, 1.595-85.351; P=0.016), pN stage (0 vs. 3) (HR, 2.788; 95% CI, 1.502-5.174; P=0.001), and completion of planned chemotherapy (HR, 2.213; 95% CI, 1.618-3.028; P<0.001) were determined as independent prognostic factors for DFS. Conclusions: S-1 and CAPOX AC regimens did not show significant difference in over-5yr DFS after curative gastrectomy in patients with stage II or III GC. The pT, pN stage, and completion of planned chemotherapy were prognostic factors for GC recurrence.

• Journal of the Korean Orthopaedic Association
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• v.56 no.3
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• pp.245-252
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• 2021

Purpose: This study examined the radiological and clinical outcomes of internal fixation using a reconstruction plate and 21G circumferential wire in comminuted midshaft clavicular fractures. Materials and Methods: A retrospective cohort study was performed on 51 patients between 2005 and 2019. Thirty-two patients underwent internal fixation with a reconstruction plate and a 21G circumferential wire with minimal soft tissue detachment, and 19 patients underwent surgery without a wire. The patients were assessed with the radiographic parameters, the University of California at Los Angeles (UCLA) score, and the visual analogue scale (VAS) pain score. Based on this, patients who operated without a circumferential wire were set as the control group, and the differences in bone union between the two groups were compared. Results: Thirty-two patients were followed-up for an average of 65 weeks, and 19 patients in the control group were followed-up for an average of 56 weeks. The radiological evaluation confirmed the anatomical reduction and bone union in all 32 patients. No case of nonunion was present. The UCLA score was 32.38 on average and 33.11 in the control group (p=0.395). The VAS score was 1.00 on average and 0.84 in the control group (p=0.668). A significant difference in the bony union time was observed between the group who underwent internal fixation with a reconstruction plate and a 21G circumferential wire with minimal soft tissue detachment, and the control group (p=0.015). On the other hand, there was no statistical significance when other variables were controlled (p=0.107). Conclusion: For displaced midshaft clavicular fractures, internal fixation using a reconstruction plate and 21G circumferential wire maintained accurate anatomical reduction. The satisfactory clinical and radiological results mean that internal fixation using a reconstruction plate and 21G circumferential wire may be a good option for surgical treatment.