Background: This study was performed to evaluate etiologies and secular trends in primary amenorrhea in South Korea. Methods: This retrospective multi-center study analyzed 856 women who were diagnosed with primary amenorrhea between 2000 and 2016. Clinical characteristics were compared according to categories of amenorrhea (hypergonadotropic/hypogonadotropic hypogonadism, eugonadism, disorders of sex development) or specific causes of primary amenorrhea. In addition, we assessed secular trends of etiology and developmental status based on the year of diagnosis. Results: The most frequent etiology was eugonadism (39.8%). Among specific causes, Müllerian agenesis was most common (26.2%), followed by gonadal dysgenesis (22.4%). Women with hypergonadotropic hypogonadism were more likely to have lower height and weight, compared to other categories. In addition, the proportion of cases with iatrogenic or unknown causes increased significantly in hypergonadotropic hypogonadism category, but overall, no significant secular trends were detected according to etiology. The proportion of anovulation including polycystic ovarian syndrome increased with time, but the change did not reach statistical significance. Conclusion The results of this study provide useful clinical insight on the etiology and secular trends of primary amenorrhea. Further large-scale, prospective studies are necessary.

Objective: To evaluate the trueness and precision of full-arch scans acquired using five intraoral scanners and investigate the factors associated with the dimensional accuracy of the intraoral scan data. Methods: Nine adult participants (mean age, 34.3 ± 8.3 years) were recruited. Four zirconium spheres (Ø 6 mm) were bonded to the canines and the molars. Following acquisition of reference scans using an industrial-grade scanner, five intraoral scanners, namely i500, CS3600, Trios 3, iTero, and CEREC Omnicam, were used to scan the arches. Linear distances between the four reference spheres were automatically calculated, and linear mixed model analysis was performed to compare the trueness and precision of the intraoral scan data among the different scanners. Results: The absolute mean trueness and precision values for all intraoral scanners were 76.6 ± 79.3 and 56.6 ± 52.4 µm, respectively. The type of scanner and the measured linear distances had significant effects on the accuracy of the intraoral scan data. With regard to trueness, errors in the intermolar dimension and the distance from the canine to the contralateral molar were greater with Omnicam than with the other scanners. With regard to precision, the error in the linear distance from the canine to the molar in the same quadrant was greater with Omnicam and CS3600 than with the other scanners. Conclusions The dimensional accuracy of intraoral scan data may differ significantly according to the type of scanner, with the amount of error in terms of trueness being clinically significant.

Background: For the 2018–2019 season, the national influenza immunization program expanded to cover children aged from 6 months to 12 years in Korea. This study aimed to analyze vaccine effectiveness (VE) against influenza in children visiting the pediatric emergency room at a tertiary hospital during the 2018-2019 season. Methods: Patients tested for influenza antigens from October 1st 2018 to May 31st 2019 at the pediatric emergency room of Samsung Medical Center were included. Patients' influenza antigen test results, influenza vaccination history, and underlying medical conditions were reviewed retrospectively. VE was estimated from the test-negative design study. Results: Among the 2,901 visits with influenza test results 1,692 visits of 1,417 patients were included for analysis. Among these 1,417 patients, 285 (20.1%) were positive (influenza A, n = 211, 74.0%; influenza B, n = 74, 26.0%). The VE in all patients was 36.4% (95% confidence interval [CI], 13.9 to 53.1). The VE for influenza A was 37.6% (95% CI, 12.6 to 55.5) and VE for influenza B was 24.0% (−38.5 to 58.3). The VE in the age group 6 months to 12 years was significant with a value of 35.6% (95% CI, 10.5 to 53.7); it was not statistically significant in the age group 13 to 18 years. In a multivariate logistic regression model, patients who received an influenza vaccination were less likely to get influenza infection (OR, 0.6; 95% CI, 0.4 to 0.8; P = 0.001), with significant confounding factors such as age group 13 to 18 years (OR, 0.5; 95% CI, 0.3 to 0.8; P = 0.003) and underlying hematology-oncology disease (OR, 0.3;95% CI, 0.1 to 0.6; P = 0.002). Conclusion We report moderate effectiveness of influenza vaccination in previously healthy children aged from 6 months to 12 years in the 2018-2019 season.

Objective: To evaluate the trueness and precision of full-arch scans acquired using five intraoral scanners and investigate the factors associated with the dimensional accuracy of the intraoral scan data. Methods: Nine adult participants (mean age, 34.3 ± 8.3 years) were recruited. Four zirconium spheres (Ø 6 mm) were bonded to the canines and the molars. Following acquisition of reference scans using an industrial-grade scanner, five intraoral scanners, namely i500, CS3600, Trios 3, iTero, and CEREC Omnicam, were used to scan the arches. Linear distances between the four reference spheres were automatically calculated, and linear mixed model analysis was performed to compare the trueness and precision of the intraoral scan data among the different scanners. Results: The absolute mean trueness and precision values for all intraoral scanners were 76.6 ± 79.3 and 56.6 ± 52.4 µm, respectively. The type of scanner and the measured linear distances had significant effects on the accuracy of the intraoral scan data. With regard to trueness, errors in the intermolar dimension and the distance from the canine to the contralateral molar were greater with Omnicam than with the other scanners. With regard to precision, the error in the linear distance from the canine to the molar in the same quadrant was greater with Omnicam and CS3600 than with the other scanners. Conclusions The dimensional accuracy of intraoral scan data may differ significantly according to the type of scanner, with the amount of error in terms of trueness being clinically significant.

Background: For the 2018–2019 season, the national influenza immunization program expanded to cover children aged from 6 months to 12 years in Korea. This study aimed to analyze vaccine effectiveness (VE) against influenza in children visiting the pediatric emergency room at a tertiary hospital during the 2018-2019 season. Methods: Patients tested for influenza antigens from October 1st 2018 to May 31st 2019 at the pediatric emergency room of Samsung Medical Center were included. Patients' influenza antigen test results, influenza vaccination history, and underlying medical conditions were reviewed retrospectively. VE was estimated from the test-negative design study. Results: Among the 2,901 visits with influenza test results 1,692 visits of 1,417 patients were included for analysis. Among these 1,417 patients, 285 (20.1%) were positive (influenza A, n = 211, 74.0%; influenza B, n = 74, 26.0%). The VE in all patients was 36.4% (95% confidence interval [CI], 13.9 to 53.1). The VE for influenza A was 37.6% (95% CI, 12.6 to 55.5) and VE for influenza B was 24.0% (−38.5 to 58.3). The VE in the age group 6 months to 12 years was significant with a value of 35.6% (95% CI, 10.5 to 53.7); it was not statistically significant in the age group 13 to 18 years. In a multivariate logistic regression model, patients who received an influenza vaccination were less likely to get influenza infection (OR, 0.6; 95% CI, 0.4 to 0.8; P = 0.001), with significant confounding factors such as age group 13 to 18 years (OR, 0.5; 95% CI, 0.3 to 0.8; P = 0.003) and underlying hematology-oncology disease (OR, 0.3;95% CI, 0.1 to 0.6; P = 0.002). Conclusion We report moderate effectiveness of influenza vaccination in previously healthy children aged from 6 months to 12 years in the 2018-2019 season.

Purpose: We aimed to evaluate the clinical features of adolescents who visit emergency departments (EDs) with chest discomfort, and analyze the implications of underlying medical conditions for the development of cardiogenic chest discomfort. Methods: We reviewed the medical records of adolescents (13-18 years) with chest discomfort who visited a tertiary hospital ED in Seoul, Korea from 2014 through 2018. Sex, age, duration and character of the discomfort, symptoms and signs, ED length of stay, abnormal findings of vital signs, chest radiograph, electrocardiogram, and elevated concentrations of cardiac enzymes were reviewed. Final diagnosis was based on cardiac evaluations within 1 year after the index visit. Underlying medical conditions were defined as visits to the cardiology, pulmonology or hematology-oncology clinics at least twice in the preceding year. Initial suspicious clinical findings were defined as palpitation, syncope or high blood pressure. Logistic regression was used to identify predictors for cardiac etiology. Results: Of the 231 patients, 43 (18.6%) and 69 (29.9%) had underlying medical conditions and initial suspicious clinical findings, respectively. The predictors for cardiac etiology were underlying medical conditions (odds ratio, 4.28; 95% confidence interval, 1.09-16.73), initial suspicious clinical findings (4.77; 1.36-16.77), abnormal electrocardiogram (11.54; 3.22-41.32), and elevated concentration of troponin I (66.52; 5.37-823.55). The patients with cardiogenic chest discomfort had a longer median ED length of stay (281.0 minutes [interquartile range, 215.5-369.0] vs. 199.5 [132.8-298.0]; P = 0.004) and a higher hospitalization rate (48.3% vs. 13.4%; P < 0.001) than those with non-cardiogenic chest discomfort. Conclusion It may be necessary to recognize underlying medical conditions and initial suspicious clinical findings in EDs prior to cardiac evaluation in adolescents with chest discomfort.

Purpose: We aimed to evaluate the clinical features of adolescents who visit emergency departments (EDs) with chest discomfort, and analyze the implications of underlying medical conditions for the development of cardiogenic chest discomfort. Methods: We reviewed the medical records of adolescents (13-18 years) with chest discomfort who visited a tertiary hospital ED in Seoul, Korea from 2014 through 2018. Sex, age, duration and character of the discomfort, symptoms and signs, ED length of stay, abnormal findings of vital signs, chest radiograph, electrocardiogram, and elevated concentrations of cardiac enzymes were reviewed. Final diagnosis was based on cardiac evaluations within 1 year after the index visit. Underlying medical conditions were defined as visits to the cardiology, pulmonology or hematology-oncology clinics at least twice in the preceding year. Initial suspicious clinical findings were defined as palpitation, syncope or high blood pressure. Logistic regression was used to identify predictors for cardiac etiology. Results: Of the 231 patients, 43 (18.6%) and 69 (29.9%) had underlying medical conditions and initial suspicious clinical findings, respectively. The predictors for cardiac etiology were underlying medical conditions (odds ratio, 4.28; 95% confidence interval, 1.09-16.73), initial suspicious clinical findings (4.77; 1.36-16.77), abnormal electrocardiogram (11.54; 3.22-41.32), and elevated concentration of troponin I (66.52; 5.37-823.55). The patients with cardiogenic chest discomfort had a longer median ED length of stay (281.0 minutes [interquartile range, 215.5-369.0] vs. 199.5 [132.8-298.0]; P = 0.004) and a higher hospitalization rate (48.3% vs. 13.4%; P < 0.001) than those with non-cardiogenic chest discomfort. Conclusion It may be necessary to recognize underlying medical conditions and initial suspicious clinical findings in EDs prior to cardiac evaluation in adolescents with chest discomfort.

Voiding cystourethrography (VCUG) demonstrates the anatomy of the urinary system and is used to detect the presence/absence of vesicoureteral reflux. It is the most important modality for urological fluoroscopic examination in children. For improved patient care, it is important to understand and perform VCUG appropriately. Therefore, an in-depth review of VCUG protocols and techniques has been presented herein. In addition, tips, tricks, and pitfalls associated with the technique have also been addressed.

OBJECTIVE: This study aimed to analyze intracranial vessels using brain computed tomography angiography (CTA) and scoring systems to diagnose brain death and predict poor neurologic outcomes of postcardiac arrest patients.METHODS: Initial brain CTA images of postcardiac arrest patients were analyzed using scoring systems to determine a lack of opacification and diagnose brain death. The primary outcome was poor neurologic outcome, which was defined as cerebral performance category score 3 to 5. The frequency, sensitivity, specificity, positive predictive value, negative predictive value, and area under receiver operating characteristic curve for the lack of opacification of each vessel and for each scoring system used to predict poor neurologic outcomes were determined.RESULTS: Patients with poor neurologic outcomes lacked opacification of the intracranial vessels, most commonly in the vein of Galen, both internal cerebral veins, and the mid cerebral artery (M4). The 7-score results (P=0.04) and 10-score results were significantly different (P=0.04) between outcome groups, with an area under receiver operating characteristic of 0.61 (range, 0.48 to 0.72). The lack of opacification of each intracranial vessel and all scoring systems exhibited high specificity (100%) and positive predictive values (100%) for predicting poor neurologic outcomes.CONCLUSION: Lack of opacification of vessels on brain CTA exhibited high specificity for predicting poor neurologic outcomes of patients after cardiac arrest.
Angiography ; Brain Death ; Brain ; Cerebral Arteries ; Cerebral Veins ; Heart Arrest ; Humans ; Hypothermia ; ROC Curve ; Sensitivity and Specificity

OBJECTIVE: To prospectively evaluate the diagnostic performance of computer-aided diagnosis (CAD) for detection of thyroid cancers via ultrasonography (US). MATERIALS AND METHODS: This study included 50 consecutive patients with 117 thyroid nodules on US during the period between June 2016 and July 2016. A radiologist performed US examinations using real-time CAD integrated into a US scanner. We compared the diagnostic performance of radiologist, the CAD system, and the CAD-assisted radiologist for the detection of thyroid cancers. RESULTS: The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the CAD system were 80.0, 88.1, 83.3, 85.5, and 84.6%, respectively, and were not significantly different from those of the radiologist (p > 0.05). The CAD-assisted radiologist showed improved diagnostic sensitivity compared with the radiologist alone (92.0% vs. 84.0%, p = 0.037), while the specificity and PPV were reduced (85.1% vs. 95.5%, p = 0.005 and 82.1% vs. 93.3%, p = 0.008). The radiologist assisted by the CAD system exhibited better diagnostic sensitivity and NPV than the CAD system alone (92.0% vs. 80.0%, p = 0.009 and 93.4% vs. 88.9%, p = 0.013), while the specificities and PPVs were not significantly different (88.1% vs. 85.1%, p = 0.151 and 83.3% vs. 82.1%, p = 0.613, respectively). CONCLUSION: The CAD system may be an adjunct to radiological intervention in the diagnosis of thyroid cancer.
Artificial Intelligence ; Diagnosis* ; Humans ; Prospective Studies ; Sensitivity and Specificity ; Thyroid Gland* ; Thyroid Neoplasms ; Thyroid Nodule* ; Ultrasonography*