OBJECTIVE: To compare the image quality of low-dose (LD) computed tomography (CT) obtained using a deep learning-based denoising algorithm (DLA) with LD CT images reconstructed with a filtered back projection (FBP) and advanced modeled iterative reconstruction (ADMIRE).MATERIALS AND METHODS: One hundred routine-dose (RD) abdominal CT studies reconstructed using FBP were used to train the DLA. Simulated CT images were made at dose levels of 13%, 25%, and 50% of the RD (DLA-1, -2, and -3) and reconstructed using FBP. We trained DLAs using the simulated CT images as input data and the RD CT images as ground truth. To test the DLA, the American College of Radiology CT phantom was used together with 18 patients who underwent abdominal LD CT. LD CT images of the phantom and patients were processed using FBP, ADMIRE, and DLAs (LD-FBP, LD-ADMIRE, and LD-DLA images, respectively). To compare the image quality, we measured the noise power spectrum and modulation transfer function (MTF) of phantom images. For patient data, we measured the mean image noise and performed qualitative image analysis. We evaluated the presence of additional artifacts in the LD-DLA images.RESULTS: LD-DLAs achieved lower noise levels than LD-FBP and LD-ADMIRE for both phantom and patient data (all p < 0.001). LD-DLAs trained with a lower radiation dose showed less image noise. However, the MTFs of the LD-DLAs were lower than those of LD-ADMIRE and LD-FBP (all p < 0.001) and decreased with decreasing training image dose. In the qualitative image analysis, the overall image quality of LD-DLAs was best for DLA-3 (50% simulated radiation dose) and not significantly different from LD-ADMIRE. There were no additional artifacts in LD-DLA images.CONCLUSION: DLAs achieved less noise than FBP and ADMIRE in LD CT images, but did not maintain spatial resolution. The DLA trained with 50% simulated radiation dose showed the best overall image quality.
Artifacts ; Humans ; Noise ; Tomography, X-Ray Computed

PURPOSE: Abnormalities in hemostasis and coagulation have been suggested in chronic renal failure (CRF). In this study, we compared processes of thrombus formation between rats with CRF and those with normal kidney function. MATERIALS AND METHODS: CRF was induced by 5/6 ablation/infarction of the kidneys in Sprague-Dawley rats, and surviving rats after 4 weeks were used. Ferric chloride (FeCl3)-induced thrombosis in the carotid artery was induced to assess thrombus formation. Whole blood clot formation was evaluated using rotational thromboelastometry (ROTEM). Platelet aggregation was assessed with impedance platelet aggregometry. RESULTS: FeCl3-induced thrombus formation was initiated faster in the CRF group than in the control group (13.2±1.1 sec vs. 17.8±1.0 sec, p=0.027). On histological examination, the maximal diameters of thrombi were larger in the CRF group than in the control group (394.2±201.1 µm vs. 114.0±145.1 µm, p=0.039). In extrinsic pathway ROTEM, the CRF group showed faster clot initiation (clotting time, 59.0±7.3 sec vs. 72.8±5.0 sec, p=0.032) and increased clot growth kinetics (α angle, 84.8±0.2° vs. 82.0±0.6°, p=0.008), compared to the control group. Maximal platelet aggregation rate was higher in the CRF group than in the control group (58.2±0.2% vs. 44.6±1.2%, p=0.006). CONCLUSION: Our study demonstrated that thrombogenicity is increased in rats with CRF. An activated extrinsic coagulation pathway may play an important role in increasing thrombogenicity in CRF.
Animals ; Blood Platelets ; Carotid Arteries ; Electric Impedance ; Hemostasis ; Kidney ; Kidney Failure, Chronic* ; Kinetics ; Models, Animal* ; Platelet Aggregation ; Rats* ; Rats, Sprague-Dawley ; Thrombelastography ; Thrombosis

No abstract available.
Humans* ; Sebum*

PURPOSE: This study shows the change in emergency room use behavior by homeless patients after implementation of the ‘Seoul Type Citizen Sympathy Emergency Room Project’ in July 2015. METHODS: A retrospective study was conducted in a public hospital between January 2014 and December 2014 and January 2016 and December 2016. Homeless patients who visited the emergency room in 2014 and 2016 were compared based on age, gender, mode of insurance, admission, revisit within 48 hours, length of stay (LOS) in the emergency department (ED), total cost, and major diagnostic category. RESULTS: A total of 3,642 homeless patients were enrolled during the study period, of which 1,876 visited in 2014 and 1,766 in 2016. Fewer homeless patients in 2016 revisited within 48 hours (p=0.046). Homeless in 2016 had a shorter ED LOS (p < 0.001) and lower total cost (p=0.040). More homeless patients who visited due to alcohol revisited within 48 hours in 2016 (p=0.036). Moreover, these patients did not have a different ED LOS (p=0.060) or total cost (p=0.475). Medicaid homeless patients were less connected compared health insurance by screening, brief intervention, referral to treatment program. CONCLUSION: Comparison of homeless patients who visited the emergency room in 2014 and 2016 revealed fewer total homeless patients in 2016, as well as less revisits within 48 hours, shorter ED LOS and lower total cost. These findings indicate that the ‘Seoul Type Citizen Sympathy Emergency Room Project’ was effective in the emergency room, but improvements for alcohol and medicaid homeless patients are needed.
Alcoholics ; Emergencies ; Emergency Medical Services ; Emergency Service, Hospital ; Health Policy ; Homeless Persons ; Hospitals, Public ; Humans ; Insurance ; Insurance, Health ; Length of Stay ; Mass Screening ; Medicaid ; Referral and Consultation ; Retrospective Studies

Indoor animal husbandry environments are inevitably contaminated with endotoxins. Endotoxin exposure is associated with various inflammatory illnesses in animals. This cross-sectional study evaluated the relationship between the degree of endotoxin exposure and the cellular and humoral immune profiles of fattening pigs. Blood samples were taken from the jugular vein of 47 pigs from ten pig farms in Korea. Whole blood cell counts and plasma immunoglobulin (Ig) classes were determined. Peripheral-blood mononuclear cells were stimulated in vitro with concanavalin A for 48 h, and cytokines released into culture supernatants were measured. The barns in which the pigs lived were assessed for endotoxin levels in the total and respirable dust by using the limulus amebocyte lysate kinetic QCL method. Low and high endotoxin exposures were defined as ≤ 30 and > 30 EU/m³, respectively. Compared to pigs with low endotoxin exposure (n = 19), highly exposed pigs (n = 28) had higher circulating neutrophil and lymphocyte (particularly B cells) counts, IgG and IgE levels, interferon-gamma (IFNγ) and interleukin (IL)-4 productions, and lower IgA levels and tumor necrosis factor-alpha (TNFα) production. The IL-4, IFNγ, and TNFα levels significantly correlated with endotoxin level and/or pig age. Constant exposure of pigs to high levels of airborne endotoxins can lead to aberrant immune profiles.
Agriculture ; Animal Husbandry ; Animals ; Blood Cell Count ; Concanavalin A ; Cross-Sectional Studies ; Cytokines ; Dust ; Endotoxins ; Horseshoe Crabs ; Housing ; Immunity, Cellular ; Immunoglobulin A ; Immunoglobulin E ; Immunoglobulin G ; Immunoglobulins ; In Vitro Techniques ; Interferon-gamma ; Interleukin-4 ; Interleukins ; Jugular Veins ; Korea ; Lymphocytes ; Methods ; Neutrophils ; Plasma ; Swine ; Tumor Necrosis Factor-alpha

PURPOSE: In recent years, the number of elderly patients visiting from residential aged care facilities (RACFs) has been increasing. We analyzed a comparison of characteristics between patients who visited the ER with diseases from RACFs and those who visited from home. METHODS: A retrospective study was conducted in a public hospital between January 2013 and December 2014. The subjects included patients who visited the ED from RACFs and elderly patients who visited the ED from home. Comparisons of the following parameters were made between the two groups: gender, age, mode of insurance, mode of ED visit, mobile status, Charlson comorbidity index (CCI), chief complaint, final results in the ED, and length of stay (LOS) in the ED and hospital. RESULTS: A total of 7,603 patients were enrolled during the study period. There were 6,401 elderly patients who visited from home and 1,202 patients who visited from RACFs. Patients from RACFs were older than those from home (79.90±8.01 vs. 75.78±7.26, p<0.001). More patients from RACFs were on Medicaid (56.6% vs. 27.9%, p<0.001), took more ambulance (86.3% vs. 49.4%, p<0.001), more bedridden (68.2% vs. 6.4%, p<0.001), and higher CCI (2.38±1.99 vs. 1.45±1.84, p<0.001). Compared with patients from home, those from RACFs showed a significantly higher proportion of admission (63.2% vs. 32.9%, p<0.001), ED LOS (403.03±361.77 vs. 277.07±258.82, p<0.001), and hospital LOS (19.65±18.58 vs. 15.67±15.63, p<0.001). Patients from RACFs showed especially longer ED LOS from discharged ED than those from home (388.87±422.88 vs. 221.90±215.30, p<0.001). CONCLUSION: Compared with elderly patients from home, patients from RACFs also had higher admission rate and longer ED LOS, as well as hospital LOS. Patients from RACFs had long ED LOS. The findings in this study suggest that there could be ED overcrowding in the near future.
Aged* ; Ambulances ; Comorbidity ; Emergencies* ; Emergency Service, Hospital* ; Hospitals, Public ; Humans ; Insurance ; Length of Stay ; Medicaid ; Nursing Homes ; Residential Facilities ; Retrospective Studies

PURPOSE: This study aimed to explore the association between increased level of ambient particulate matter and emergency room visits for chronic obstructive pulmonary disease (COPD) exacerbations. METHODS: A retrospective study was conducted. We enrolled patients who lived in Seoul, Korea and were diagnosed with COPD in the emergency room between January 2012 and December 2014. Meteorological factors [daily highest temperature, lowest temperature, mean temperature, diurnal temperature, rainfall, relative humidity, amount of sunshine and particulate matter less than 10 µm (PM 10)] between December 2011 and December 2014 in Seoul were acquired from the Korea Meteorological Administration. We used a multiple Poisson regression model with daily patient's number of COPD as a response variable and meteorological factors as explanatory variable. Variable selection was done via an Elastic net. RESULTS: There was a total of 1,179 emergency visits for acute exacerbations of COPD patients. PM10 (before 4, 10, 11, 15, 16, 17, 22, 24, 27, 28 day), rainfall (before 1, 6, 8, 16, 18 day), relative humidity (before 2, 8), and daily temperature difference (5, 10, 15 day) had a relationship and a lag effect with COPD exacerbations. CONCLUSION: This study showed that an increased concentration of PM10 was associated with COPD exacerbations. A future study that reinforces the limitation of this study is necessary to get a helpful index for an adequate response of medical institution and efficient placement of medical personnel.
Emergencies* ; Emergency Service, Hospital* ; Humans ; Humidity ; Korea ; Lung Diseases ; Meteorological Concepts ; Particulate Matter* ; Pulmonary Disease, Chronic Obstructive* ; Regression Analysis ; Retrospective Studies ; Seoul ; Sunlight

Falls and fall-related injuries are common in older populations and have negative effects on quality of life and independence. Falling is also associated with increased morbidity, mortality, nursing home admission, and medical costs. Korea has experienced an extreme demographic shift with its population aging at the fastest pace among developed countries, so it is important to assess fall risks and develop interventions for high-risk populations. Guidelines for the prevention of falls were first developed by the Korean Association of Internal Medicine and the Korean Geriatrics Society. These guidelines were developed through an adaptation process as an evidence-based method; four guidelines were retrieved via systematic review and the Appraisal of Guidelines for Research and Evaluation II process, and seven recommendations were developed based on the Grades of Recommendation, Assessment, Development, and Evaluation framework. Because falls are the result of various factors, the guidelines include a multidimensional assessment and multimodal strategy. The guidelines were developed for primary physicians as well as patients and the general population. They provide detailed recommendations and concrete measures to assess risk and prevent falls among older people.
Accidental Falls ; Aging ; Developed Countries ; Geriatrics ; Humans ; Internal Medicine ; Korea* ; Methods ; Mortality ; Nursing Homes ; Quality of Life

Percutaneous transhepatic biliary drainage (PTBD) is a modality that is used to decompress obstructive jaundice due to impacted stones, benign stricture or cancer. The PTBD catheter is removed percutaneously after the restoration of internal biliary drainage. We experienced a case of a 62-year-old man with peritonitis due to the migration of the PTBD catheter into the peritoneal cavity; we successfully removed it using peroral endoscopy. Although rare, the PTBD catheter may migrate into the peritoneal cavity during the removal of it. In these cases, clinicians should consider the peroral endoscopic removal of the PTBD catheter.
Catheters* ; Cholestasis ; Constriction, Pathologic ; Drainage* ; Endoscopes ; Endoscopy ; Humans ; Jaundice, Obstructive ; Middle Aged ; Peritoneal Cavity ; Peritonitis*

Falls and fall-related injuries are common amongst the elderly population and have deleterious effects on the quality of life or independence in daily living in the elderly. Falling is also associated with substantial morbidity, mortality, nursing home admission, and an increase in medical costs. Given that Korea has shown an extreme demographic shift with its population aging at the fastest pace among developed countries, assessment of fall risks and implementing intervention strategies to the high-risk population are getting more important. The guidelines for the prevention of falls were developed first by The Korean Association of Internal Medicine and The Korean Geriatric Society. These guidelines were developed by an adaptation process and the use of an evidence-based method; 4 guidelines were retrieved by systematic review and by the AGREE (appraisal of guidelines for research and evaluation) II process and 7 statements were made based on the grading of evidence, and these recommendations followed the GRADE (grades of recommendation, assessment, development, and evaluation) framework. Given that falls result from a various combination of many factors, the guidelines contain multidimensional assessment measures and multimodal strategies to prevent falls. These guidelines were developed not only for use by primary physicians but also for patients and the general population. Therefore, these guidelines provide detailed recommendations and concrete measures for the assessment of the risk of a fall and to prevent falls amongst the elderly population.
Accidental Falls ; Aged ; Aging ; Developed Countries ; Humans ; Internal Medicine ; Korea* ; Mortality ; Nursing Homes ; Quality of Life