Objective: To develop a deep-learning-based bone age prediction model optimized for Korean children and adolescents and evaluate its feasibility by comparing it with a Greulich-Pyle-based deep-learning model. Materials and Methods: A convolutional neural network was trained to predict age according to the bone development shown on a hand radiograph (bone age) using 21036 hand radiographs of Korean children and adolescents without known bone development-affecting diseases/conditions obtained between 1998 and 2019 (median age [interquartile range {IQR}], 9 [7–12] years; male:female, 11794:9242) and their chronological ages as labels (Korean model). We constructed 2 separate external datasets consisting of Korean children and adolescents with healthy bone development (Institution 1: n = 343;median age [IQR], 10 [4–15] years; male: female, 183:160; Institution 2: n = 321; median age [IQR], 9 [5–14] years; male:female, 164:157) to test the model performance. The mean absolute error (MAE), root mean square error (RMSE), and proportions of bone age predictions within 6, 12, 18, and 24 months of the reference age (chronological age) were compared between the Korean model and a commercial model (VUNO Med-BoneAge version 1.1; VUNO) trained with Greulich-Pyle-based age as the label (GP-based model). Results: Compared with the GP-based model, the Korean model showed a lower RMSE (11.2 vs. 13.8 months; P = 0.004) and MAE (8.2 vs. 10.5 months; P = 0.002), a higher proportion of bone age predictions within 18 months of chronological age (88.3% vs. 82.2%; P = 0.031) for Institution 1, and a lower MAE (9.5 vs. 11.0 months; P = 0.022) and higher proportion of bone age predictions within 6 months (44.5% vs. 36.4%; P = 0.044) for Institution 2. Conclusion The Korean model trained using the chronological ages of Korean children and adolescents without known bone development-affecting diseases/conditions as labels performed better in bone age assessment than the GP-based model in the Korean pediatric population. Further validation is required to confirm its accuracy.

Background: The Korean Society of Thoracic Radiology (KSTR) recently constructed a nation-wide coronavirus disease 2019 (COVID-19) database and imaging repository, referred to the Korean imaging cohort of COVID-19 (KICC-19) based on the collaborative efforts of its members. The purpose of this study was to provide a summary of the clinico-epidemiological data and imaging data of the KICC-19. Methods: The KSTR members at 17 COVID-19 referral centers retrospectively collected imaging data and clinical information of consecutive patients with reverse transcription polymerase chain reaction-proven COVID-19 in respiratory specimens from February 2020 through May 2020 who underwent diagnostic chest computed tomography (CT) or radiograph in each participating hospital. Results: The cohort consisted of 239 men and 283 women (mean age, 52.3 years; age range, 11–97 years). Of the 522 subjects, 201 (38.5%) had an underlying disease. The most common symptoms were fever (n = 292) and cough (n = 245). The 151 patients (28.9%) had lymphocytopenia, 86 had (16.5%) thrombocytopenia, and 227 patients (43.5%) had an elevated CRP at admission. The 121 (23.4%) needed nasal oxygen therapy or mechanical ventilation (n = 38; 7.3%), and 49 patients (9.4%) were admitted to an intensive care unit.Although most patients had cured, 21 patients (4.0%) died. The 465 (89.1%) subjects underwent a low to standard-dose chest CT scan at least once during hospitalization, resulting in a total of 658 CT scans. The 497 subjects (95.2%) underwent chest radiography at least once during hospitalization, which resulted in a total of 1,475 chest radiographs. Conclusion The KICC-19 was successfully established and comprised of 658 CT scans and 1,475 chest radiographs of 522 hospitalized Korean COVID-19 patients. The KICC-19 will provide a more comprehensive understanding of the clinical, epidemiological, and radiologic characteristics of patients with COVID-19.

Adefovir dipivoxil (ADV) is commonly used as an antiviral agent in the treatment of chronic hepatitis B or human immunodeficiency virus infection. Nephrotoxicity has been shown to occur at daily dosages of 60-120 mg. Fanconi's syndrome is a generalized dysfunction of the renal proximal tubular cells, which is usually accompanied by complications. Here we report a case of Fanconi's syndrome in a chronic hepatitis B patient who had been treated with a prolonged regimen of ADV at 10 mg/day. A 47-year-old man complained of severe back and chest-wall pain. He had chronic hepatitis B and had been treated with ADV at a daily dose of 10 mg for 38 months. He was hospitalized because of severe bone pain, and laboratory and radiologic findings suggested a diagnosis of Fanconi's syndrome with osteomalacia. After discontinuation of the ADV, he recovered and was discharged from hospital. His laboratory findings had normalized within 2 weeks. This case indicates that Fanconi's syndrome can be acquired by a chronic hepatitis B patient taking ADV at a conventional dosage of 10 mg/day. Therefore, patients treated with long-term ADV should be checked regularly for the occurrence of ADV-induced Fanconi's syndrome.
Adenine ; Fanconi Syndrome ; Hepatitis ; Hepatitis B ; Hepatitis B virus ; Hepatitis B, Chronic ; HIV ; Humans ; Middle Aged ; Organophosphonates ; Osteomalacia

Appendiceal mucocele is a cystic dilatation of the appendiceal lumen with mucus, which may be caused by either benign or malignant diseases. In this report, five cases of appendiceal mucocele are reported, three of which had a preoperative diagnosis of mucocele, whereas the others were found incidentally during the operation under the diagnosis of intussusception and periappendiceal abscess. All five patients underwent surgical resections, including one ileocecal resection and four right hemicolectomies. Histopathology revealed a mucinous cystadenoma in four cases, and a mucinous cystadenocarcinoma in one. There was no disease-related death during 18 months of follow-up.
Abscess ; Appendix ; Cystadenocarcinoma, Mucinous ; Cystadenoma, Mucinous ; Diagnosis ; Dilatation ; Follow-Up Studies ; Humans ; Intussusception ; Mucocele* ; Mucus

During endoscopy, most endoscopists insert endoscopes into the esophagus without visual aid in order to minimize the discomfort to patients. However, studies have shown that visual guided insertion imposes little discomfort, is safe and can increase the diagnostic rate of abnormal pathology of the throat. As for the treatment of hypopharyngeal lesions, cases of endoscopic treatment are rare and any guidelines have not been clearly defined yet. However, endoscopic treatment may be feasible in selected cases. Several procedures, such as endoscopic mucosal resection with cap (EMR-C) and saline injection polypectomy can be applied. We experienced seven patients who had benign hypopharyngeal masses that were removed endoscopically without serious complications. Compared to surgical treatment, endoscopic removal of the benign hypopharyngeal tumors does not require general anesthesia; it is simple, less invasive and less costly. Therefore, endoscopy should be regarded as a treatment option. However, further studies are required before widespread application of endoscopic removal for the definitive treatment of hypopharyngeal masses, including malignancies.
Anesthesia, General ; Audiovisual Aids ; Endoscopes ; Endoscopy ; Esophagus ; Humans ; Pathology ; Pharynx

In rare cases, early gastric cancer resembles the endoscopic features of a submucosal tumor (SMT). A correct histological diagnosis is difficult with repeated biopsy specimens because they are covered with normal mucosa. Some features known to suggest malignant SMT include a size greater than 3 to 5 cm, a rapid growth rate, echoheterogeneity and irregular margins on endoscopic ultrasonography (EUS). Various techniques including US-guided biopsy, partial removal by an endoscopic snare excision, as well as EUS with a fine needle aspiration were used to enhance the diagnostic accuracy. We recently experienced a case of early gastric cancer, presenting as a submucosal tumor-like lesion, which was confirmed by endoscopic mucosal resection. We report this case with a review of the relevant literature.
Adenocarcinoma* ; Biopsy ; Biopsy, Fine-Needle ; Diagnosis ; Endosonography ; Mucous Membrane ; SNARE Proteins ; Stomach Neoplasms

Barrett's esophagus is considered as a premalignant condition in which columnar epithelium replaces the normal esophageal squamous epithelium. The diagnosis of Barrett's esophagus is based on the endoscopic finding of columnar epithelium lining the distal esophagus and histologic confirmation of the presence of specialized intestinal metaplasia. According to the extent of the metaplastic lining from the esophagogastric junction, Barrett's esophagus has been divided into long-segment (> or =3 cm in length) and short-segment (<3 cm in length). Long-segment Barrett's esophagus can be easily identified at endoscopy, but it is difficult to separate short-segment Barrett's esophagus from intestinal metaplasia of cardia. It has been reported that Barrett's CK 7/20 pattern is an objective marker of Barrett's mucosa, and can differentiate Barrett's mucosa from gastric intestinal metaplasia. We report here two cases of adenocarcinoma of esophagus arising from short-segment Barrett's esophagus, diagnosed by endoscopic and histologic findngs, and treated by endoscopic mucosal resection.
Adenocarcinoma* ; Barrett Esophagus* ; Cardia ; Diagnosis ; Endoscopy ; Epithelium ; Esophagogastric Junction ; Esophagus ; Metaplasia ; Mucous Membrane

Backgrounds/Aims: This study aimed to estimate the seroepidemiology of hepatitis B virus (HBV) infection with emphasis on the transmission of HBV infection between mothers and their children. METHODS: For 452 patients with HBV associated chronic liver disease, and 1,098 of their offspring, who visited Korea University Kuro Hospital from February, 2000 to February, 2001, HBsAg was tested by radioimmunoassay. RESULTS: Among siblings whose mothers were HBsAg-positive, the overall prevalence rate of HBV infection was 44.9% (140/312) and decreased with decreasing age (54.7% in > or =20 years old age group, 33.3% in 10-19 years old age group, 7.6% in <10 years old age group). The estimated proportion of perinatal infection out of modes of HBV transmissions in the general population was 38% in <10 years and 63.4% in 10-19 years. CONCLUSION: The present hepatitis B vaccination strategies -especially against perinatal infection- of Korea have performed to their utmost. More effective methods for the prevention of HBV transmission are now needed.
Child ; Epidemiology ; Hepatitis B Surface Antigens ; Hepatitis B virus ; Hepatitis B* ; Hepatitis* ; Humans ; Korea ; Liver Diseases* ; Liver* ; Mothers ; Prevalence ; Radioimmunoassay ; Siblings* ; Vaccination

Cryoglobulinemia is the presence of globulins in the serum that precipitate on exposure to cold temperatures (cryoglobulins). Pulmonary complications of cryoglobulinemia include interstial infiltration, impaired gas exchange, small airway disease and pleurisy. Only one other acute respiratory distress syndrome(ARDS) case has been described in patients with cryoglobulinemia. A 55-years old man was admitted with dyspnea. He had been diagnosed as being a hepatitis B virus antigen carrier 15 years age. On the first admission, chest radiography showed a bilateral pleural effusion and a patchy infiltration on both lungs. On protein-and immuno-electrophoresis, cryoglobulinemia was confirmed. The patient was treated with corticosteroid and plasmapheresis. Forty-five days after the diagnosis, the patient complained of progressive dyspnea and showed a diffuse bilateral pulmonary infiltration on chest radiography. Despite intensive care with mechanical ventilation, the patient died as consequence of hypoxemia and multiple systemic organ failure. On a pathologic examination of the postmortem lung biopsy, multiple necrotizing vasculitis and increased infiltration of the lymphocytes and monocytes were observed. In conclusion, ARDS developed as a result of pulmonary hemorrhage due to cryoglobulinemia-associated vasculitis.
Anoxia ; Biopsy ; Cold Temperature ; Cryoglobulinemia ; Diagnosis ; Dyspnea ; Globulins ; Hemorrhage ; Hepatitis B virus ; Humans ; Critical Care ; Lung ; Lymphocytes ; Monocytes ; Plasmapheresis ; Pleural Effusion ; Pleurisy ; Radiography ; Respiration, Artificial ; Respiratory Distress Syndrome, Adult* ; Thorax ; Vasculitis