Objective: It is unknown whether artificial intelligence-based computer-aided detection (AI-CAD) can enhance the accuracy of chest radiograph (CR) interpretation in real-world clinical practice. We aimed to compare the accuracy of CR interpretation assisted by AI-CAD to that of conventional interpretation in patients who presented to the emergency department (ED) with acute respiratory symptoms using a pragmatic randomized controlled trial. Materials and Methods: Patients who underwent CRs for acute respiratory symptoms at the ED of a tertiary referral institution were randomly assigned to intervention group (with assistance from an AI-CAD for CR interpretation) or control group (without AI assistance). Using a commercial AI-CAD system (Lunit INSIGHT CXR, version 2.0.2.0; Lunit Inc.). Other clinical practices were consistent with standard procedures. Sensitivity and false-positive rates of CR interpretation by duty trainee radiologists for identifying acute thoracic diseases were the primary and secondary outcomes, respectively. The reference standards for acute thoracic disease were established based on a review of the patient’s medical record at least 30 days after the ED visit. Results: We randomly assigned 3576 participants to either the intervention group (1761 participants; mean age ± standard deviation, 65 ± 17 years; 978 males; acute thoracic disease in 472 participants) or the control group (1815 participants; 64 ± 17 years; 988 males; acute thoracic disease in 491 participants). The sensitivity (67.2% [317/472] in the intervention group vs. 66.0% [324/491] in the control group; odds ratio, 1.02 [95% confidence interval, 0.70–1.49]; P = 0.917) and false-positive rate (19.3% [249/1289] vs. 18.5% [245/1324]; odds ratio, 1.00 [95% confidence interval, 0.79–1.26]; P = 0.985) of CR interpretation by duty radiologists were not associated with the use of AI-CAD. Conclusion AI-CAD did not improve the sensitivity and false-positive rate of CR interpretation for diagnosing acute thoracic disease in patients with acute respiratory symptoms who presented to the ED.

OBJECTIVE: To investigate whether computed tomography (CT) and fluorine-18-labeled fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) may be applied to distinguish thymic epithelial tumors (TETs) from benign cysts in the anterior mediastinum. MATERIALS AND METHODS: We included 262 consecutive patients with pathologically proven TETs and benign cysts 5 cm or smaller who underwent preoperative CT scans. In addition to conventional morphological and ancillary CT findings, the relationship between the lesion and the adjacent mediastinal pleura was evaluated qualitatively and quantitatively. Mean lesion attenuation was measured on CT images. The maximum standardized uptake value (SUVmax) was obtained with FDG-PET scans in 40 patients. CT predictors for TETs were identified with multivariate logistic regression analysis. For validation, we assessed the diagnostic accuracy and inter-observer agreement between four radiologists in a size-matched set of 24 cysts and 24 TETs using a receiver operating characteristic curve before and after being informed of the study findings. RESULTS: The multivariate analysis showed that post-contrast attenuation of 60 Hounsfield unit or higher (odds ratio [OR], 12.734; 95% confidence interval [CI], 2.506–64.705; p = 0.002) and the presence of protrusion from the mediastinal pleura (OR, 9.855; 95% CI, 1.749–55.535; p = 0.009) were the strongest CT predictors for TETs. SUVmax was significantly higher in TETs than in cysts (5.3 ± 2.4 vs. 1.1 ± 0.3; p < 0.001). After being informed of the study findings, the readers' area under the curve improved from 0.872–0.955 to 0.949–0.999 (p = 0.066–0.149). Inter-observer kappa values for protrusion were 0.630–0.941. CONCLUSION: Post-contrast CT attenuation, protrusion from the mediastinal pleura, and SUVmax were useful imaging features for distinguishing TETs from cysts in the anterior mediastinum.
Humans ; Logistic Models ; Mediastinum ; Multivariate Analysis ; Pleura ; Positron-Emission Tomography ; ROC Curve ; Thymus Neoplasms ; Tomography, X-Ray Computed

Korea is located within the East Asian-Australian flyway of wild migratory birds during the fall and winter seasons. Consequently, the likelihood of introduction of numerous subtypes and pathotypes of the Avian influenza (AI) virus to Korea has been thought to be very high. In the current study, we surveyed wild bird feces for the presence of AI virus that had been introduced to Korea between September 2017 and February 2018. To identify and characterize the AI virus, we employed commonly used methods, namely, virus isolation (VI) via egg inoculation, real-time reverse transcription-polymerase chain reaction (rRT-PCR), conventional RT-PCR (cRT-PCR) and a newly developed next generation sequencing (NGS) approach. In this study, 124 out of 11,145 fresh samples of wild migratory birds tested were rRT-PCR positive; only 52.0% of VI positive samples were determined as positive by rRT-PCR from fecal supernatant. Fifty AI virus specimens were isolated from fresh fecal samples and typed. The cRT-PCR subtyping results mostly coincided with the NGS results, although NGS detected the presence of 11 HA genes and four NA genes that were not detected by cRT-PCR. NGS analysis confirmed that 12% of the identified viruses were mixed-subtypes which were not detected by cRT-PCR. Prevention of the occurrence of AI virus requires a workflow for rapid and accurate virus detection and verification. However, conventional methods of detection have some limitations. Therefore, different methods should be combined for optimal surveillance, and further studies are needed in aspect of the introduction and application of new methods such as NGS.
Animals ; Birds ; Feces ; Influenza in Birds ; Korea ; Methods ; Ovum ; Seasons

PURPOSE: This study evaluated the clinical and radiological results after reinforcement of the weakened medial joint capsule using Internal Brace (Arthrex) for treating severe hallux valgus. MATERIALS AND METHODS: This study reviewed 56 cases of 50 patients that were followed-up postoperatively for at least 12 months, from September 2017 until August 2018. An extended distal chevron osteotomy combined with a distal soft-tissue release was performed by a single surgeon to treat severe hallux valgus. Internal Brace was applied in 12 cases (group A) who had weakened medial joint capsules, and capsulorrhaphy was performed in 44 cases (group B), and these two groups were compared postoperatively for the clinical and radiological results. The postoperative complications were also investigated. RESULTS: No significant differences at 1-year follow-up on the Manchester-Oxford Foot Questionnaire and the patients' satisfaction scores were found between the two groups (p=0.905 and p=0.668, respectively). For the radiology, the changes of the values between before surgery and at 1-year follow-up according to the group showed no significant differences in the hallux valgus angle, intermetatarsal angle, and the hallux interphalangeal angle (p=0.986, p=0.516, p=0.754, respectively). Recurrence of hallux valgus was reported in two cases in group A, and in three cases in group B. Transfer metatarsalgia occurred in 4 cases in group B. CONCLUSION Based on these results, we recommend the capsule reinforcing technique using Internal Brace as a successful operative option for treating a weakened medial capsule in patients with severe hallux valgus.

BACKGROUND: Anemia is a major risk factor that contributes to mortality in patients with chronic kidney disease. There is controversy over the optimal hemoglobin (Hb) target in these patients. This study investigated the association between Hb level and mortality in a cohort of hemodialysis (HD) patients in Korea. METHODS: This study was a multicenter prospective observational study of maintenance HD patients that was performed for 5 years in western Seoul, Korea. Three hundred and sixty-two participants were enrolled. Laboratory values and mortality were accessed every 6 months. Repeated measures of laboratory values in each interval were averaged to obtain one semiannual mean value. The Hb values were divided into six groups: (1) Hb<9 g/dL; (2) 9 g/dL< or =Hb<10 g/dL; (3) 10 g/dL< or =Hb<11 g/dL; (4) 11 g/dL< or =Hb<12 g/dL; (5) 12 g/dL< or =Hb<13 g/dL; and (6) Hb> or =13 g/dL. We analyzed the odds ratio for all-cause mortality, based on the Hb group, and adjusted for demographics and various laboratory values. Statistics were performed with SAS, version 9.1 software (SAS Institute Inc., Cary, NC, USA). RESULTS: Mortality odds ratios relative to the reference group (10-11 g/dL) in the fully adjusted model were 3.61 for<9 g/dL; 3.17 for 9-10 g/dL*; 4.65 for 11-12 g/dL*; 5.50 for 12-13 g/dL*; and 2.05 for> or =13 g/dL (* indicates P<0.05). CONCLUSION: In this study, a Hb level of 10-11 g/dL was associated with the lowest mortality among the groups with Hb level<13 g/dL. Larger interventional trials are warranted to determine the optimal Hb target for Korean HD patients.
Anemia* ; Cohort Studies* ; Demography ; Humans ; Korea ; Mortality ; Observational Study ; Odds Ratio ; Prospective Studies ; Renal Dialysis* ; Renal Insufficiency, Chronic ; Risk Factors ; Seoul

BACKGROUND: Laser therapy for various skin conditions is one of the most common procedures in dermatology. Recently, several articles described the use of 1064 nm Q-switched Nd:YAG lasers for the treatment of benign skin lesions. Such treatment is known to trigger its therapeutic effect through a photoacoustic effect and selective photothermolysis effect. However, only a limited number of articles have dealt with the theoretical base of the photoacoustic effect of the 1064 nm Q-switched Nd:YAG laser. OBJECTIVE: To compare the wound repair process and nonselective tissue heat damage induced by three different laser modalities: the CO2 laser, Er:YAG laser, and 1064 nm Q-switched Nd:YAG laser. METHODS: We irradiated the skin of an albino rat (Sprague Dawley(R), 200~250 g) with CO2, Er:YAG, and 1064 nm Q-switched Nd:YAG lasers. Skin biopsy specimens of the irradiated areas were collected on the first, fifth, and tenth day after laser exposure. For histologic analysis, the specimens were stained with the H&E, Verhoff-Van Gieson, and Masson's trichrome protocols. RESULTS: Compared with other laser modalities, rat skin irradiated by the 1064 nm Q-switched Nd:YAG laser showed the least amount of heat damage and the quickest tissue repair response to the damage. CONCLUSION: A 1064 nm Q-switched Nd:YAG laser with a photoacoustic effect capable of ablating the epidermis and dermis can be a proper treatment modality for the removal of benign skin lesions. The 1064 nm Q-switched Nd:YAG laser may be considered as an alternative treatment option for the treatment of benign skin lesions.
Animals ; Biopsy ; Dermatology ; Dermis ; Epidermis ; Hot Temperature ; Laser Therapy ; Lasers, Gas ; Rats* ; Skin* ; Wounds and Injuries*

Recent studies recommend pegylated interferon alpha2a as the first choice treatment for chronic hepatitis B, especially when the patient is negative for HBeAg. Pegylated interferon alpha is known to show variable side effects including skin symptoms, with alopecia as the most common dermatologic side effect experienced for 10% up to 36%. pcc) Most alopecia cases related to pegylated interferon alpha were presented with telogen effluvium pattern, but alopecia areata cases are reported rarely. In this case, typically localized alopecia areata was presented with pegylated interferon alpha2a treatment in hepatitis B patient, and the course of alopecia areata seemed to be related with administration and discontinuation of pegylated interferon alpha2a.
Alopecia Areata* ; Alopecia* ; Hepatitis B ; Hepatitis B e Antigens ; Hepatitis B, Chronic* ; Hepatitis, Chronic* ; Humans ; Interferon-alpha ; Interferons* ; Skin

Maxillary enlargement is a rare complication of secondary hyperparathyroidism (SHPT). A 35-year-old Korean man undergoing chronic hemodialysis presented with a painless enlargement involving the maxilla and mandible. Plain radiography and CT scan showed bony expansion at the maxilla and mandible with multiple radiolucency. Serum intact parathyroid hormone (iPTH) was >1,600 pg/mL. Tc-99m sestamibi (MIBI) parathyroid scan and neck sonogram were compatible with SHPT. He underwent limited parathyroidectomy and commenced a course of paricalcitol. Fifteen months after surgery, maxillary enlargement and bony resorptions involving both hands markedly improved. Thirty-six months after the surgery, the serum iPTH level was 109.3 pg/mL. This is the first report in Korea documenting a patient with maxillary enlargement in SHPT who was successfully treated with limited parathyroidectomy and paricalcitol.
Adult ; Ergocalciferols ; Hand ; Humans ; Hyperparathyroidism ; Hyperparathyroidism, Secondary ; Korea ; Mandible ; Maxilla ; Neck ; Parathyroid Hormone ; Parathyroidectomy ; Renal Dialysis ; Renal Osteodystrophy

Vitiligo universalis is an uncommon variant that is rarely seen. Interestingly, vitiligo universalis often accompanies systemic diseases such as endocrinopathies. A 43-year-old man presented with whole body depigmentation and poliosis affecting most of his scalp and body hair. He had undergone a liver transplant 2 years ago due to liver cirrhosis from a chronic hepatitis B infection and has been treated for diabetes mellitus for several years. Histopathology showed no melanocytes and an absence of epidermal pigmentation on the skin. We herein report a rare case of vitiligo universalis associated with chronic viral hepatitis B.
Adult ; Diabetes Mellitus ; Hair ; Hepatitis B ; Hepatitis B, Chronic ; Hepatitis, Chronic ; Humans ; Liver ; Liver Cirrhosis ; Melanocytes ; Pigmentation ; Scalp ; Skin ; Transplants ; Vitiligo

OBJECTIVE: The purpose of this study was to investigate the stress distribution on the orthodontic mini-implant (OMI) surface and periodontal ligament of the maxillary first and second molars as well as the tooth displacement according to the OMI position in the dragon helix appliance during scissors-bite correction. METHODS: OMIs were placed at two maxillary positions, between the first and the second premolars (group 1) and between the second premolar and the first molar (group 2). The stress distribution area (SDA) was analyzed by three-dimensional finite element analysis. RESULTS: The maximal SDA of the OMI did not differ between the groups. It was located at the cervical area and palatal root apex of the maxillary first molar in groups 1 and 2, respectively, indicating less tipping in group 2. The minimal SDA was located at the root and furcation area of the maxillary second molar in groups 1 and 2, respectively, indicating greater palatal crown displacement in group 2. CONCLUSIONS: Placement of the OMI between the maxillary second premolar and the maxillary first molar to serve as an indirect anchor in the dragon helix appliance minimizes anchorage loss while maximizing the effect on scissors-bite correction.
Bicuspid ; Crowns ; Displacement (Psychology) ; Finite Element Analysis ; Molar ; Periodontal Ligament ; Tooth