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BACKGROUND: Small peripheral nerve tractography is challenging because of the trade-off among resolution, image acquisition time, and signal-to-noise ratio. PURPOSE: To optimize pixel size and slice thickness parameters for fiber tractography and diffusion tensor imaging (DTI) of the ulnar nerve at the cubital tunnel using 3T magnetic resonance imaging (MRI). MATERIAL AND METHODS: Fifteen healthy volunteers (mean age 30 ± 6.8 years) were recruited prospectively. Axial T2-weighted and DTI scans were acquired, covering the cubital tunnel, using different pixel sizes and slice thicknesses. Three-dimensional (3D) nerve tractography was evaluated for the median number and length of the reconstructed fiber tracts and visual score from 0 to 5. Two-dimensional (2D) cross-sectional DTI was evaluated for fractional anisotropy (FA) values throughout the length of the ulnar nerve. RESULTS: A pixel size of 1.3 mm2 revealed the highest number of reconstructed nerve fibers compared to that of 1.1 mm2 (P = 0.048), with a good visual score. A slice thickness of 4 mm had the highest number of reconstructed nerve fibers and visual score compared with other thicknesses (all P < 0.05). In 2D cross-sectional images, the median FA values were in the range of 0.40-0.63 at the proximal, central, and distal portions of the cubital tunnel. Inter-observer agreement for all parameters was good to excellent. CONCLUSION: For fiber tractography and DTI of the ulnar nerve at the cubital tunnel, optimal image quality was obtained using a 1.3-mm2 pixel size and 4-mm slice thickness under MR parameters of this study at 3T.
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Imagem de Tensor de Difusão/métodos , Nervo Ulnar/diagnóstico por imagem , Adulto , Anisotropia , Estudos Transversais , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Estudos Prospectivos , Nervo Ulnar/anatomia & histologia , Adulto JovemRESUMO
OBJECTIVES: To evaluate the effect of preoperative ureteral stenting duration on the outcomes of retrograde intrarenal surgery (RIRS). PATIENTS AND METHODS: We reviewed our database of patients who underwent RIRS between May 2011 and April 2017 at our institution. The patients were divided into three groups according to preoperative ureteral stenting duration: group 1: no stenting, group 2: short preoperative stenting (< 7 days) and group 3: long preoperative stenting (≥ 7 days). We compared the rate of ureteral injury, other perioperative complications, ureteral dilation and readmission, stone-free rate (SFR) and operative time among the groups. RESULTS: A total of 560 patients (215 in group 1, 177 in group 2 and 168 in group 3) were included in this study. The mean of maximum stone size was 13.1 (± 6.2) mm, the mean number of stones was 2.3 (± 1.9) and preoperative ureteral stenting duration was 7.2 (± 3.7) days. There were no significant differences in operative time (75.6, 78.5 and 82.4 min, p = 0.280), SFR (79.1, 84.2 and 81.0%, p = 0.433), ureteral injury rate (7.0, 5.1 and 2.4%, p = 0.123) and other perioperative complication rates (12.1, 6.8 and 6.0%, p = 0.061). The only one case of grade IV ureteral injury occurred in group 1 and the rate of ureteral dilation was significantly higher than in group 2 and 3 (14.9, 5.7 and 6.0%, p < 0.001). CONCLUSION: Although preoperative ureteral stenting duration has no significant effect on operative outcomes, it is an effective procedure for reducing the rate of intraoperative ureteral balloon dilation and preventing high-grade ureteral injuries.
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Cálculos Renais/cirurgia , Stents , Ureter/cirurgia , Ureteroscopia/métodos , Adulto , Idoso , Feminino , Humanos , Complicações Intraoperatórias/epidemiologia , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Complicações Pós-Operatórias/epidemiologia , Cuidados Pré-Operatórios , Estudos Retrospectivos , Resultado do Tratamento , Ureter/lesõesRESUMO
PURPOSE: To investigate the factors associated with hospital readmission (HR) after retrograde intrarenal surgery (RIRS) among renal stone patients. METHODS: The study included patients who underwent RIRS from June 2011 to December 2017. Patients who were readmitted due to surgery-related complications were evaluated retrospectively. Patient demographics including age, medical comorbidity, body mass indices, ASA score, perioperative parameters and stone factors were compared with total cohorts. HR was defined as visits to the Emergency Room or unplanned admission within 30 days after discharge. The factors affecting HR rates were analyzed using uni- and multi-variate analyses. RESULTS: A total of 572 patients were enrolled into the study. The mean age was 57.6 ± 14.1 years and the mean stone diameter was 13.4 ± 6.2 mm. The mean complication rate was 6.1% and the median hospitalization time was 2.1 ± 3.4 days. HR occurred in 20 patients (3.5%). Compared to non-admission patients, readmitted patients had a higher rate of bilateral RIRS (20.0% vs 12.2%, p = 0.035), number of stones (4.65 vs 2.2, p = 0.041) and higher stone complexity score (4.15 vs 2.11, p = 0.003). Multivariate analysis showed bilateral RIRS (OR 1.091, p = 0.031) and stone complexity (OR 1.405, p = 0.003) were significant factors to predict re-admission after RIRS. CONCLUSION: Patients with complex renal stones or those who underwent bilateral RIRS were more likely to have a higher rate of re-admission. Proper perioperative management to prevent complications should be planned based on these predictive factors.
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Cálculos Renais/cirurgia , Readmissão do Paciente/estatística & dados numéricos , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos , Fatores de Risco , Procedimentos Cirúrgicos Urológicos/métodosRESUMO
AIM: To assess the relationship between imaging features of pulmonary tuberculosis at computed tomography (CT) and adenosine deaminase (ADA) values via pleural fluid analysis in patients with pleural tuberculosis. MATERIALS AND METHODS: This retrospective study enrolled 60 patients who underwent fluid analysis for ADA and chest CT and were diagnosed with tuberculosis by culture or polymerase chain reaction of pleural fluid and sputum. The presence of centrilobular nodules, consolidation, cavitation, and mediastinal lymphadenopathy at CT were evaluated. The relationship between ADA values and the pattern of pulmonary involvement of tuberculosis was analysed. RESULTS: Pulmonary involvement was seen in 42 of the 60 patients. A centrilobular nodular pattern was seen in 37 and consolidation in 22. In 17 patients, both findings were identified. A centrilobular nodular pattern was more common than consolidation or cavitary lesions. When ADA values were high, pulmonary involvement was more frequent (p=0.002). Comparing low and high ADA groups using an obtained cut-off value of 80 IU/l, the high group had more frequent pulmonary involvement (p<0.001). CONCLUSION: Patients with tuberculous pleurisy who had high ADA values had a higher probability of manifesting pulmonary tuberculosis. High ADA values may help predict contagious pleuroparenchymal tuberculosis. The most common pulmonary involvement of tuberculous pleurisy showed a centrilobular nodular pattern.
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Adenosina Desaminase/metabolismo , Derrame Pleural/enzimologia , Tuberculose Pleural/diagnóstico por imagem , Tuberculose Pleural/enzimologia , Tuberculose Pulmonar/diagnóstico por imagem , Tuberculose Pulmonar/enzimologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia Torácica/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X/métodos , Adulto JovemRESUMO
OBJECTIVE. Appropriate radiologic interpretation of screening CT can minimize unnecessary workup and intervention. This is particularly challenging in the baseline round. We report on the quality assurance process we developed for the International Early Lung Cancer Action Program. MATERIALS AND METHODS. After initial training at the coordinating center, radiologists at 10 participating institutions and at the center independently interpreted the first 100 baseline screenings. The radiologist at the institutions had access to the center interpretations before issuing the final reports. After the first 100 screenings, the interpretations were jointly discussed. This report summarizes the results of the initial 100 dual interpretations at the 10 institutions. RESULTS. The final institution interpretations agreed with the center in 895 of the 1000 interpretations. Compared with the center, the frequency of positive results was higher at eight of the 10 institutions. The most frequent reason of discrepant interpretations was not following the protocol (n = 55) and the least frequent was not identifying a nodule (n = 3). CONCLUSION. The quality assurance process helped focus educational programs and provided an excellent vehicle for review of the protocol with participating physicians. It also suggests that the rate of positive results can be reduced by such measures.
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Detecção Precoce de Câncer/métodos , Detecção Precoce de Câncer/normas , Neoplasias Pulmonares/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Controle de QualidadeRESUMO
The white light-emitting diode (WLED) is a state-of-the-art solid state technology, which has replaced conventional lighting systems due to its reduced energy consumption, its reliability, and long life. However, the WLED presents acute challenges in device engineering, due to its lack of color purity, efficacy, and thermal stability of the lighting devices. The prime cause for inadequacies in color purity and luminous efficiency is the spectral overlapping of red components with yellow/green emissions when generating white light by pumping a blue InGaN chip with yellow YAG:Ce³âº phosphor, where red phosphor is included, to compensate for deficiencies in the red region. An innovative strategy was formulated to resolve this spectral overlapping by alternatively arranging phosphor-in-glass (PiG) through cutting and reassembling the commercial red CaAlSiN3:Eu²âº and green Lu3Al5O12:Ce³âº PiG. PiGs were fabricated using glass frits with a low softening temperature of 600°C, which exhibited excellent thermal stability and high transparency, improving life time even at an operating temperature of 200°C. This strategy overcomes the spectral overlapping issue more efficiently than the randomly mixed and patented stacking design of multiple phosphors for a remote-type WLED. The protocol for the current design of PiG possesses excellent thermal and chemical stability with high luminous efficiency and color purity is an attempt to make smarter solid state lighting for high-powered remote-type white light-emitting devices.
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Potential white light-emitting diode (LED) phosphor SrGa2S4, which remains superfluous due to its unstable nature in the presence of moisture, was successfully integrated in a high-power white LED system by developing a glass-based phosphor plate. A glass system with softening temperature at around 600°C, which lies far below the possible decomposition temperature of the sulfide phosphor, provides a stable shield. Physical properties such as thermal stability, transparency, and lower porosity along with chemical stability under operating conditions of the LEDs ensure long-term operability. H2S emission due to the decomposition of sulfide phosphors, which leads to corrosion of LED electrodes, was contained using the developed plate. Higher thermal resistivity of the developed glass system in comparison with conventional resins ensures lower thermal quenching of the luminescence and better color purity.
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As relatively new economies to the global research arena, East Asian nations have fully realized the importance of research integrity in recent decades. This article conducts document analysis to demonstrate and discuss the current situation of research integrity campaigns in Taiwan, Korea, and Japan, nations that have similar cultural backgrounds and socioeconomic statuses. This article emphasizes the common situations faced by these three nations both individually and collectively. Based on a four-pillar framework, research integrity campaigns in these nations are making progress in terms of policies and regulations, institutional management, researchers' education and training, and the handling of misconduct cases. Various issues and challenges have also emerged in this context, although these efforts may have had positive impacts on research communities in these three nations. Challenges associated with research integrity governance, institutional willingness, RCR instructor qualifications, the effectiveness of education, and the standardization of definitions of misconduct and noncompliance are also highlighted. The issues discussed in this article are expected to have implications for research communities and policy-makers in these three nations as well as in a global context.
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Increasing utilization of computed tomography (CT) has raised concerns regarding CT radiation dose and technology has been developed to achieve an appropriate balance between image quality, radiation dose, and the amount of contrast material. This study was planned to evaluate the image quality and radiation dose in pancreatic dynamic computed tomography (PDCT) with 90-kVp tube voltage and reduction of the standard amount of contrast agent, compared with 100-kVp PDCT of the research hospital's convention. Total of 51 patients with both CT protocols were included. The average Hounsfield units (HU) values of the abdominal organs and image noise were measured for objective image quality analysis. Two radiologists evaluated five categories of image qualities such as subjective image noise, visibility of small structure, beam hardening or streak artifact, lesion conspicuity and overall diagnostic performance for subjective image quality analysis. The total amount of contrast agent, radiation dose, and image noise decreased in the low-kVp group, by 24.4%, 31.7%, and 20.6%, respectively (p < 0.001). The intraobserver and interobserver agreements were moderate to substantial (k = 0.4-0.8). The contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), and figure of merit of the almost organs except psoas muscle in the low-kVp group were significantly higher (p < 0.001). Except for lesion conspicuity, both reviewers judged that subjective image quality of the 90-kVp group was better (p < 0.001). With 90-kVp tube voltage, 25% reduced contrast agent volume with advanced iteration algorithm and high tube current modulation achieved radiation dose reduction of 31.7%, as well as better image quality and diagnostic confidence.
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Meios de Contraste , Tomografia Computadorizada por Raios X , Humanos , Doses de Radiação , Tomografia Computadorizada por Raios X/métodos , Razão Sinal-Ruído , Algoritmos , Interpretação de Imagem Radiográfica Assistida por Computador/métodosRESUMO
BACKGROUND: Acute ileal diverticulitis is a rare disease mimicking acute appendicitis. Inaccurate diagnosis with a low prevalence and nonspecific symptoms leads to delayed or improper management. METHODS: This retrospective study aimed to investigate the characteristic sonographic (US) and computed tomography (CT) findings with clinical features in seventeen patients with acute ileal diverticulitis diagnosed between March 2002 and August 2017. RESULTS: The most common symptom was abdominal pain (82.3%, 14/17) localized to the right lower quadrant (RLQ) in 14 patients. The characteristic CT findings of acute ileal diverticulitis were ileal wall thickening (100%, 17/17), identification of inflamed diverticulum at the mesenteric side (94.1%, 16/17), and surrounding mesenteric fat infiltration (100%, 17/17). The typical US findings were outpouching diverticular sac connecting to the ileum (100%, 17/17), peridiverticular inflamed fat (100%, 17/17), ileal wall thickening with preserved layering pattern (94.1%, 16/17), and increased color flow to the diverticulum and surrounding inflamed fat on color Doppler imaging (100%, 17/17). The perforation group had a significantly longer hospital stay than non-perforation group (p = 0.002). In conclusion, acute ileal diverticulitis has characteristic CT and US findings that allow radiologists to accurately diagnose the disease.
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Evaluation of hepatic fibrosis is essential to prevent liver-related morbidity and mortality. Although various types of ultrasound shear wave elastography (SWE) have been used and validated, there are limited studies on the relatively newer technique, two-dimensional SWE (2D-SWE). Therefore, this study aimed to compare the diagnostic performances of 2D-SWE and point SWE (p-SWE) for evaluating liver fibrosis using histology as the reference standard. To measure liver stiffness (LS) values, 87 patients underwent 2D-SWE and p-SWE using the same machine. Technical failures and unreliable measurements were also evaluated. The diagnostic performances of 2D-SWE and p-SWE were compared using area under the receiver operating characteristic (AUROC) curve analysis. No technical failures were observed in either method; however, unreliable measurements were less frequent in 2D-SWE (1/87 [1.1%]) than in p-SWE (8/87 [9.2%]) (p < 0.001). The AUROC of the LS values of 2D-SWE were significantly higher than those of p-SWE for diagnosing significant fibrosis (0.965 vs. 0.872, p = 0.022) and cirrhosis (0.994 vs. 0.886, p = 0.042). In conclusion, 2D-SWE is more reliable and accurate than p-SWE for diagnosing hepatic fibrosis.
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BACKGROUND: Swine-origin influenza A (H1N1) virus (S-OIV) infection and scrub typhus, also known as tsutsugamushi disease can manifest as acute respiratory illnesses, particularly during the late fall or early winter, with similar radiographic findings, such as a predominance of ground-glass opacity (GGO). PURPOSE: To differentiate S-OIV infection from scrub typhus using high-resolution computed tomography (HRCT). MATERIAL AND METHODS: We retrospectively reviewed the HRCT findings of 14 patients with S-OIV infection and 10 patients with scrub typhus. We assessed the location, cross-sectional distribution, and the presence of a peribronchovascular distribution of GGO and consolidations on HRCT. We also assessed the presence of interlobular septal thickening, bronchial wall thickening, pneumothorax, pneumomediastinum, pleural effusion, and mediastinal or axillary lymph node enlargement. RESULTS: Scrub typhus was more common than S-OIV in elderly patients (P < 0.001). The monthly incidences of S-OIV and scrub typhus infection reached a peak between October and November. About 86% of S-OIV patients and 80% of scrub typhus patients presented with GGO. About 67% of the GGO lesions in S-OIV had a peribronchovascular distribution, but this was absent in scrub typhus (P = 0.005). Consolidation (93% vs. 10%, P < 0.001) and bronchial wall thickening (43% vs. 0%, P = 0.024) were more frequent in S-OIV infection than scrub typhus. Interlobular septal thickening (90% vs. 36%, P = 0.013) and axillary lymphadenopathy (90% vs. 0%, P < 0.001) were more common in scrub typhus than S-OIV infection. CONCLUSION: There was considerable overlap in HRCT findings between S-OIV infection and scrub typhus. However, S-OIV showed a distinctive peribronchovascular distribution of GGO lesions. Consolidation and bronchial wall thickening were seen more frequently in S-OIV infection, whereas interlobular septal thickening and axillary lymphadenopathy were more common in scrub typhus. Thus, CT could be helpful for differential diagnosis between S-OIV infection and scrub typhus.
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Vírus da Influenza A Subtipo H1N1 , Influenza Humana/diagnóstico por imagem , Radiografia Torácica/métodos , Sistema Respiratório/diagnóstico por imagem , Tifo por Ácaros/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adolescente , Adulto , Distribuição por Idade , Idoso , Axila , Brônquios , Criança , Feminino , Humanos , Pulmão/diagnóstico por imagem , Linfonodos/diagnóstico por imagem , Masculino , Enfisema Mediastínico/diagnóstico por imagem , Mediastino/diagnóstico por imagem , Pessoa de Meia-Idade , Variações Dependentes do Observador , Derrame Pleural/diagnóstico por imagem , Pneumotórax/diagnóstico por imagem , Estudos Retrospectivos , Traqueia/diagnóstico por imagem , Adulto JovemRESUMO
OBJECTIVES: To compare the osteoporosis-predicting ability of computed tomography (CT) indexes in abdomen-pelvic CT using the proximal femur and the reliability of measurements in two- and three-dimensional analyses. METHODS: Four hundred thirty female patients (age range, 50-96 years) who underwent dual-energy X-ray absorptiometry and abdominal-pelvic CT within 1 month were retrospectively selected. The volumes of interest (VOIs) from the femoral head to the lesser trochanter and the femoral neck were expressed as 3DFemur. Round regions of interest (ROIs) of image plane drawn over the femoral neck touching the outer cortex were determined as 2Dcoronal. In HU histogram analysis (HUHA), the percentages of HU histogram ranges related to the ROI or VOI were classified as HUHAFat (<0 HU) and HUHABone (126 HU≤). Diagnostic performance, correlation analysis and measurement reliability were analyzed by receiver operating characteristic curves, correlation coefficient and interobserver correlation coefficient (ICC), respectively. RESULTS: AUCs of each HUHA and mean-HU measurement on 2D-ROI and 3D-VOI were 0.94 or higher (P < 0.001). Both 3DFemur-Mean-HU and 3DFemur-HUHABone showed the highest AUC (0.96). The cut-off value of 3DFemur-Mean-HU was 231HU or less, (sensitivity: 94.8%; specificity: 85.0%; correlation coefficient: -0.65; P <0.001) for diagnosis of osteoporosis. There was no superiority between AUCs in 2D-ROI and 3D-VOI measurements (P > 0.05). Reliability of the 3D-VOI measurement showed perfect agreement (ICC ≥ 0.94), and 2D-ROI showed moderate to good agreement (ICC range: 0.63~0.84). CONCLUSIONS: CT indexes on 3D-VOI for predicting femoral osteoporosis showed similar diagnostic accuracy with better reproducibility of measurement, compared with 2D-ROI.
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OsteoporoseRESUMO
Background: The role of high-flow arteriovenous fistula (AVF) in cardiovascular morbidity in hemodialysis (HD) patients is very likely under-recognized. We assessed the relationship between high access flow (Qa) and myocardial fibrosis in HD patients. Methods: Myocardial fibrosis was assessed by native T1 relaxation times on non-contrast cardiac magnetic resonance imaging and a potential marker of fibrosis. Serum levels of galectin-3, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and monocyte chemoattractant protein 1 (MCP-1) were measured in 101 HD patients who underwent regular monitoring of AVF Qa. A high-flow AVF was defined as a Qa >2 L/min. Results: Hemodialysis patients showed significantly higher galectin-3 value and increased T1 relaxation time compared to healthy volunteers, suggesting increased myocardial fibrosis in uremic cardiomyopathy. In HD patients, 20 (19.8%) had a Qa > 2L/min, and they had significantly higher cardiac output, cardiac index, left ventricular mass, and increased T1 times than those with a Qa ≤ 2 L/min. Also, serum galectin-3 and NT-proBNP levels were much higher in the high Qa group, indicating a close relationship between the high Qa, increased myocardial fibrosis, and the risk of heart failure (HF) in HD patients. It is interesting that a higher AVF Qa for myocardial fibrosis was independent of several traditional cardiovascular risk factors as well as serum levels of NT-proBNP and MCP-1. Conclusions: A supra-physiologically high Qa can be related to myocardial fibrosis and increased risk of HF in HD patients. Regular Qa monitoring could allow early detection of a high-flow AVF that could arise cardiac complications.
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BACKGROUND/AIMS: Pulmonary toxicities of coronavirus disease 2019 (COVID-19) vaccination are exceedingly rare. However, there are a few reported cases after mRNA vaccination, especially from Asian countries. The purpose of this study was to report the clinical characteristics of patients with COVID-19 vaccine-related pneumonitis (CV-P) and to review cases reported in the literature. METHODS: We performed a prospective, observational case series analysis. RESULTS: Eleven patients with a median age of 80 years were enrolled. Ten patients developed CV-P after BNT162b2-mRNA vaccination and one after ChAdOx1 nCoV-19 vaccination. We identified various patterns of CV-P, including transient infiltration, life-threatening acute respiratory distress syndrome, and aggravation of underlying interstitial lung disease. Most patients showed favorable outcomes with good responses to corticosteroid therapy. CONCLUSION: Identifying the mechanism of CV-P requires further investigation; however, radiological and laboratory findings in our case series support inflammatory dysregulation in the lung parenchyma after vaccination. Clinicians should consider CV-P in patients with atypical lung infiltration, no specific etiologies, and recent COVID-19 vaccination.
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COVID-19 , Pneumonia , Idoso de 80 Anos ou mais , Vacina BNT162 , COVID-19/prevenção & controle , Vacinas contra COVID-19/efeitos adversos , ChAdOx1 nCoV-19 , Humanos , Estudos Prospectivos , RNA Mensageiro , VacinaçãoRESUMO
Diffuse-type tenosynovial giant cell tumor (D-TSGCT), previously known as pigmented villonodular synovitis, is a locally aggressive neoplasm that may arise from the synovium, bursa, or tendon sheath. D-TSGCT is usually monoarticular and can be classified into intra- and extra-articular forms, the latter of which is rarer. Here, we report a case of D-TSGCT in a 64-year-old female that involved the entire flexor and extensor tendon sheaths of both wrists. We describe the ultrasonography and MRI findings, as well as review the relevant literature.
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Ultrasonography is a useful technique to detect soft tissue changes of rheumatoid arthritisnot only synovitis, but also tenosynovitis, bursitis, and enthesitis-even at a subclinical stage. However, radiologists tend to focus on synovitis in daily practice, and unusual peri- or extraarticular manifestations of rheumatoid arthritis are difficult to detect at the initial presentation. This pictorial essay describes a broad spectrum of ultrasonographic findings in tendons, bursae, ligaments, subcutaneous tissues, bones, and nerves to assist in the accurate diagnosis of rheumatoid arthritis.
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Purpose: To assess the predictive factors and describe the imaging features of mediastinal lymph node (MLN) metastases in patients with head and neck cancer. Materials and Methods: We compared the clinical features and disease characteristics (sex, age, site of primary tumor, histologic type, history of prior treatments, TNM stages, and metastasis in cervical LNs) of patients with head and neck cancers between the MLN metastasis and no MLN metastasis groups. We also evaluated the chest CT (distribution and maximum dimension of the largest LN) and PET/CT (maximum standardized uptake value) features of MLN metastases based on the MLN classification. Results: Of the 470 patients with head and neck cancer, 55 (11.7%) had MLN metastasis, involving 150 mediastinal stations. Hypopharynx cancer, recurrent tumor, T4 stage, N2/N3 stages, and M1 stage were found to be significant predicting factors for MLN metastasis. The most common location of MLN metastasis was ipsilateral station 2 (upper paratracheal LNs, 36.4%), followed by ipsilateral station 11 (interlobar LNs, 27.3%) and ipsilateral station 10 (hilar LNs, 25.5%). Conclusion: Metastasis to MLNs should be considered in patients with head and neck cancer, especially in cases that are associated with a hypopharyngeal cancer, recurrent tumor, and high TNM stages.
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A cation substitution in Cu2ZnSn(S,Se)4 (CZTSSe) offers a viable strategy to reduce the open-circuit voltage (Voc)-deficit by altering the characteristics of band-tail states, antisite defects, and related defect clusters. Herein, we report a facile single process, i.e., simply introducing a thin Ag layer on a metallic precursor, to effectively improve the device characteristics and performances in kesterite (Agx,Cu1-x)2ZnSn(Sy,Se1-y)4 (ACZTSSe) solar cells. Probing into the relationship between the external quantum efficiency derivative (dEQE/dλ) and device performances revealed the Voc-deficit characteristics in the ACZTSSe solar cells as a function of Cu and Ag contents. The fabricated champion ACZTSSe solar cell device showed an efficiency of 12.07% and a record low Voc-deficit of 561 mV. Thorough investigations into the mechanism underpinning the improved performance in the ACZTSSe device further revealed the improved band-tailing characteristic, effective minority carrier lifetime, and diode factors as well as reduced antisite defects and related defect clusters as compared to the CZTSSe device. This study demonstrates the feasibility of effectively suppressing antisite defects, related defect clusters, and band-tailing characteristics by simply introducing a thin Ag layer on a metallic precursor in the kesterite solar cells, which in turn effectively reduces the Voc-deficit.