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PURPOSE: This work aims to assess standard evaluation practices used by the research community for evaluating medical imaging classifiers, with a specific focus on the implications of class imbalance. The analysis is performed on chest X-rays as a case study and encompasses a comprehensive model performance definition, considering both discriminative capabilities and model calibration. MATERIALS AND METHODS: We conduct a concise literature review to examine prevailing scientific practices used when evaluating X-ray classifiers. Then, we perform a systematic experiment on two major chest X-ray datasets to showcase a didactic example of the behavior of several performance metrics under different class ratios and highlight how widely adopted metrics can conceal performance in the minority class. RESULTS: Our literature study confirms that: (1) even when dealing with highly imbalanced datasets, the community tends to use metrics that are dominated by the majority class; and (2) it is still uncommon to include calibration studies for chest X-ray classifiers, albeit its importance in the context of healthcare. Moreover, our systematic experiments confirm that current evaluation practices may not reflect model performance in real clinical scenarios and suggest complementary metrics to better reflect the performance of the system in such scenarios. CONCLUSION: Our analysis underscores the need for enhanced evaluation practices, particularly in the context of class-imbalanced chest X-ray classifiers. We recommend the inclusion of complementary metrics such as the area under the precision-recall curve (AUC-PR), adjusted AUC-PR, and balanced Brier score, to offer a more accurate depiction of system performance in real clinical scenarios, considering metrics that reflect both, discrimination and calibration performance. CLINICAL RELEVANCE STATEMENT: This study underscores the critical need for refined evaluation metrics in medical imaging classifiers, emphasizing that prevalent metrics may mask poor performance in minority classes, potentially impacting clinical diagnoses and healthcare outcomes. KEY POINTS: Common scientific practices in papers dealing with X-ray computer-assisted diagnosis (CAD) systems may be misleading. We highlight limitations in reporting of evaluation metrics for X-ray CAD systems in highly imbalanced scenarios. We propose adopting alternative metrics based on experimental evaluation on large-scale datasets.

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Aims: This study aims to comprehensively examine the surface morphology of fiber posts after undergoing various disinfection methods, utilizing scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Materials and Methods: Twenty-one fiber posts were randomly allocated into seven experimental groups, each consisting of three samples. The disinfection methods employed were as follows: GC - no disinfection treatment; GAL - immersion in 70% alcohol, following the manufacturer's recommended protocol; GHP - soaking in 2.5% sodium hypochlorite for a duration of 10 minutes; GCL - soaking in 2% chlorhexidine gluconate for a period of five minutes; GAC - 30-second etching with 35% phosphoric acid; GPH - soaking in 10% hydrogen peroxide for a duration of 20 minutes; and GSL - autoclave sterilization. Following the disinfection procedures, SEM was employed to scrutinize the surface topography of the posts, while EDX was utilized to identify the chemical elements present on the sample surfaces. Subsequently, a descriptive analysis was conducted on the SEM images and EDX data. Results: SEM analysis revealed that all groups exhibited regions with epoxy resin-coated fibers alongside sections with exposed glass fibers. Analysis of the EDX data indicated that there were no significant differences in the predominant chemical elements across the groups. Carbon (C) and oxygen (O) registered the highest peaks, followed by silicon (Si), zirconium (Zr), sodium (Na), aluminum (Al), and calcium (Ca). Conclusions: The disinfection methods under investigation did not induce substantial alterations in the surface morphology of the fiber posts.

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The purpose of this study is to evaluate radiation exposure in newborns undergoing imaging tests during the first 30 days of neonatal intensive care unit (NICU) hospitalization. A retrospective cohort study was conducted from November 2018 to April 2019 with newborns admitted to the NICU. Thermoluminescent dosimeters (TLD-100™) measured radiation emitted during imaging exams over 1 month, with a comparison between measured and estimated radiation. The cohort exhibited a median gestational age of 33.0 (31.0, 37.0) weeks, a median birth weight of 1840 (1272, 2748) g, and a median length of stay of 25.5 (11.7, 55.0) days. Eighty-four patients underwent 314 imaging tests, with an estimated radiation dose (ERD) per patient of 0.116 mSv and a measured radiation dose (MDR) of 0.158 mSv. ERD consistently underestimated MDR, with a mean difference of -0.043 mSv (-0.049 to -0.036) in the Bland-Altman analysis. The regression equation was as follows: difference MRD - ERD = -1.7 × (mean (MRD + ERD)) + 0.056. The mean estimated radiation dose per exam was 0.030 mSv, and the chest X-rays accounted for 63.26% of total exams. The median number of radiographic incidences per patient was 2 (1, 4), with 5 patients undergoing three or more exams in a single day. CONCLUSION: Radiation exposure in these newborns was underestimated, emphasizing the need for awareness regarding associated risks and strict criteria for requesting radiological exams. Lung ultrasound is a radiation-free and effective option in managing respiratory diseases in newborns, reducing the reliance on chest X-rays. WHAT IS KNOWN: • Radiation used in diagnostic exams is not risk-free. • Radiation risk is much higher in small Infants due to the exposure area and the prolonged expectance of life. WHAT IS NEW: • Radiation exposure is underestimated in the neonatal population. • The study found a mean radiation exposure in neonates about 5% of the mean annual dose in the general population.

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Com o propósito de compreender a realidade do atendimento odontológico e contribuir para o planejamento do acesso a estes serviços, o presente estudo realizou uma investigação sobre a cobertura de procedimentos diagnósticos por imagem em odontologia ofertados pelo Sistema Único de Saúde no estado de Minas Gerais (SUS-MG). Foi realizada revisão de dados secundários, coletados através do Sistema de Informações Ambulatoriais do Sistema Único de Saúde (SIA-SUS), correlacionando-os a dados do Censo Demográfico de 2022, de modo a permitir uma análise aprofundada do panorama atual da radiologia odontológica na rede de atenção à saúde bucal do SUS-MG. Foi constatado que a macrorregião Centro foi responsável pela maioria absoluta dos procedimentos realizados no período abrangido pelo estudo, enquanto a macrorregião do Triângulo do Sul apresentou mais procedimentos por número de habitantes. A radiografia periapical/interproximal foi o exame mais solicitado até o ano de 2020, quando houve uma súbita interrupção. Desde então, a radiografia panorâmica passou a ser a mais solicitada. A desigualdade no acesso às tecnologias diagnósticas odontológicas parece ser ainda uma realidade em Minas Gerais. A disseminação de conhecimento sobre o padrão de utilização dos serviços de saúde pode impactar positivamente na diminuição da iniquidade no acesso à saúde.

In order to understand the reality of dental care and contribute to planning access to these services, this study investigated the coverage of diagnostic imaging procedures in dentistry offered by the Unified Health System in the state of Minas Gerais (SUS-MG). A review of secondary data collected through the Outpatient Information System of the Unified Health System (SIA-SUS) was carried out, correlating it with data from the 2022 Demographic Census, in order to allow an in-depth analysis of the current panorama of dental radiology in the SUS-MG oral health care network. It was found that the Central macro-region was responsible for the absolute majority of procedures carried out in the period covered by the study, while the Southern Triangle macro-region had more procedures per number of inhabitants. Periapical/interproximal radiography was the most requested exam until 2020, when there was a sudden interruption. Since then, panoramic radiography has become the most requested. Inequality in access to dental diagnostic technologies still seems to be a reality in Minas Gerais. Disseminating knowledge about the pattern of use of health services can have a positive impact on reducing inequality in access to health.

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TbxPr1-xAl2are ferrimagnetic materials exhibiting magnetocaloric effect that have gained considerable attention due to their potential use as an alternative in refrigeration, magnetic sensors and in information storage technology. Here using the mean field approach numerical simulations were conducted forx= 0.1, 0.2, 0.3, 0.4, 0.5, and 0.75, to analyze selected physical properties, such as x-ray and neutron powder diffraction, magnetization and heat capacity. The simulations successfully reproduced the experimental data providing a comprehensive characterization and improved understanding of this family of compound.

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ABSTRACT Introduction: Body composition assessment (BCA) using anthropometric measurements (AM) is used to monitor the nutritional and health status of the elderly. As predictor variables, MAs must be valid, practical, and quick, as they favor adherence and avoid possible resistance and embarrassment on the part of those being assessed and being minimally invasive. Objective: To develop and validate equations using accessible and minimally invasive anthropometric measurements for BCA in elderly women. Methods: 100 women (68.1±6.15 years) were randomly assigned to two groups: validation (n=40; 68.1±6.15 years); and estimation (n=60; 68.4±6.70 years). DXA was selected as the criterion measure, and MAs (body mass, height, skinfolds, circumferences) were selected as predictor variables. Means were compared using the paired Student's t-test; correlations were verified using Pearson's r-test; equations using Multiple Linear Regression. The level of agreement between the groups' results was checked using the Bland-Altman technique. Results: Two equations developed and tested (E3 and E4) met the validation criteria as they showed adequate correlation coefficients (E3: r=0.73; E4: r=0.70), low constant errors (E3: EC= −0.56; E4: EC=-0.90), total error (E3: ET=3.22; E4: ET=3.06) lower than the Standard Error of Estimate (E3: EPE=3.24; E4: EPE=3.21), indicating no statistically significant difference between the two BCA techniques observed (p>0.05). The Bland-Altman technique showed good agreement between the results of the two techniques. Conclusion: Two were validated: E3 (%Gdxa= −41.556 + 4.041(BMI) + 0.165(DcCox) − 0.440(CircCox) + 0.269(CircQuad) − 0.053(BMI)²); and E4 (%GdxaE4= 15.329 + 1.044(BMI) −1.055(CircAbra) + 0.282(CircQuad) + 0.164(DcCox) − 0.262(CircCox)). Notably, the small number of measurements were located in areas of the body that are easily accessible and have little body exposure, which minimizes possible embarrassment and favors adherence by the elderly. Level of Evidence IV; Correlational study to build a predictive equation.

RESUMEN Introducción: La evaluación de la composición corporal (ECC) mediante medidas antropométricas (MA) se utiliza para monitorizar el estado nutricional y de salud de las personas mayores. Las MA, como variables predictoras, deben ser válidas, prácticas y rápidas, ya que favorecen la adherencia y evitan posibles resistencias y vergüenzas por parte de los evaluados, además de ser mínimamente invasivas. Objetivo: Desarrollar y validar ecuaciones utilizando medidas antropométricas de fácil acceso y mínimamente invasivas para la ECC en mujeres de edad avanzada. Métodos: 100 mujeres (68,1±6,15 años) asignadas aleatoriamente a dos grupos: validación (n=40; 68,1±6,15 años); estimación (n=60; 68,4±6,70 años). Se seleccionó la DXA como medida criterio, y las MA (masa corporal, estatura, pliegues cutáneos, circunferencias) como variables predictoras. Las medias se compararon mediante la prueba t de Student emparejada; las correlaciones se comprobaron mediante la prueba r de Pearson; las ecuaciones mediante Regresión Lineal Múltiple. El nivel de concordancia entre los resultados de los grupos se comprobó mediante la técnica de Bland-Altman. Resultados: Dos ecuaciones desarrolladas y probadas (E3 y E4) cumplieron los criterios de validación, ya que mostraron coeficientes de correlación adecuados (E3: r=0,73; E4: r=0,70), errores constantes bajos (E3: EC= −0,56; E4: EC=-0,90), error total (E3: ET=3,22; E4: ET=3,06) inferior al error estándar de estimación (E3: EPE=3,24; E4: EPE=3,21), lo que indica que no se observaron diferencias estadísticamente significativas entre las dos técnicas de ECC (p>0,05). La técnica de Bland-Altman mostró una buena concordancia entre los resultados de las dos técnicas. Conclusión: Se validaron dos: E3 (%Gdxa= −41,556 + 4,041(IMC) + 0,165(DcCox) − 0,440(CircCox) + 0,269(CircQuad) − 0,053(IMC)²); y E4 (%GdxaE4= 15,329 + 1,044(IMC) −1,055(CircAbra) + 0,282(CircQuad) + 0,164(DcCox) − 0,262(CircCox)). Es de destacar que el reducido número de mediciones se localizaron en zonas del cuerpo de fácil acceso y con poca exposición corporal, lo que minimiza posibles situaciones embarazosas y favorece la adherencia por parte de los ancianos. Nivel de Evidencia IV; Estudio correlacional para construir una ecuación predictiva.

RESUMO Introdução: A avaliação da composição corporal (ACC) com auxílio das medidas antropométricas (MA) é utilizado no acompanhamento do estado nutricional e de saúde das populações idosas. As MAs como variáveis preditoras, devem ser válidas, práticas e rápidas, pois favorecem a adesão e evitam possíveis resistências e constrangimento das avaliadas, além de minimamente invasivas. Objetivo: Desenvolver e validar equações utilizando medidas antropométricas de fácil acesso e minimamente invasivas, para ACC de idosas. Métodos: 100 mulheres (68,1±6,15 anos) distribuídas aleatoriamente por dois grupos: validação (n=40; 68,1±6,15 anos); estimativa (n=60; 68,4±6,70 anos). Como medida critério selecionou-se a DXA, como variáveis preditoras as MAs (massa corporal, estatura, dobras cutâneas, circunferências). As médias foram comparadas com o teste t de Student pareado; as correlações verificadas com o teste r Pearson; as equações com a Regressão Linear Múltipla. O nível de concordância entre os resultados dos grupos foi verificado com a técnica Bland-Altman. Resultados: Duas equações desenvolvidas e testadas (E3 e E4) atenderam aos critérios de validação, pois, apresentaram coeficientes de correlação adequados (E3: r=0,73; E4: r=0,70), erros constantes baixos (E3: EC= −0,56; E4: EC=-0,90), erro total (E3: ET=3,22; E4: ET=3,06) menores que o Erro Padrão de Estimativa (E3: EPE=3,24; E4: EPE=3,21), indicando não existir diferença estatisticamente significativa entre as duas técnicas de ACC observadas (p>0,05). A técnica Bland-Altman demonstrou boa concordância entre os resultados das duas técnicas. Conclusão: Duas equações foram validadas: E3 (%Gdxa= −41,556 + 4,041(IMC) + 0,165(DcCox) - 0,440(CircCox) + 0,269(CircQuad) - 0,053(IMC)²); e E4 (%GdxaE4= 15,329 + 1,044(IMC) −1,055(CircAbra) + 0,282(CircQuad) + 0,164(DcCox) - 0,262(CircCox)). Destaca-se o fato do reduzido número de medidas situarem-se em áreas corporais de fácil acesso e de pouca exposição corporal, que minimizam possíveis constrangimentos e favorecem a adesão das idosas. Nível de Evidência IV; Estudo correlacional para construção de equação preditiva.

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Introducción: A pesar de su trascendencia, algunos hechos, apenas conocidos en la actualidad, favorecieron el crecimiento de la radiología en Cuba. La documentación sobre ellos es sumamente escasa y se encuentra muy dispersa, lo que dificulta sobremanera el acceso a ella. El rescate de esa información contribuye al conocimiento de la historia de la radiología en Cuba. Objetivo: Identificar cronológicamente hechos significativos, aunque poco conocidos, que influyeron en el progreso y reconocimiento de la radiología cubana y que obligan a reevaluar su historia. Métodos: Se utilizaron los métodos analítico-sintético, deductivo-inductivo, así como los submétodos cronológico y geográfico. Resultados: Fueron recogidos ―con una caracterización sintética― quince sucesos notables, poco conocidos, más algunos apuntes sobre la docencia de la radiología en estomatología. Conclusiones: Entre los hechos identificados destacan los que deben ser considerados como los primeros acercamientos a los rayos X en Cuba, que obligan a reescribir lo actualmente aceptado a ese respecto. Además de los revisados aquí, otros eventos significativos en la edificación de la historia de la radiología en Cuba deben ser abordados en futuras investigaciones.

Introduction: Despite their significance, some facts, barely known today, favored the growth of radiology in Cuba. The documentation about them is extremely scarce and is widely dispersed, which makes access to it extremely difficult. The rescue of this information contributes to the knowledge of the history of radiology in Cuba. Objective: To chronologically identify significant events, although little-known, that influenced the progress and recognition of Cuban radiology and that force us to reevaluate its history. Methods: Analytical-synthetic, deductive-inductive methods were used, as well as chronological and geographical sub-methods. Results: Fifteen notable, little-known events―with a synthetic characterization―were collected, plus some notes on the teaching of radiology in stomatology. Conclusions: Among the facts identified are those that should be considered the first approaches to X-rays in Cuba which force us to rewrite what is currently accepted in this regard. In addition to those reviewed here, other significant events in the construction of the history of radiology in Cuba should be studied in future research.

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Introducción: La identificación por cotejo de regis-tros odontológicos representa una metodología científicamente consolidada. La estrategia más co-mún reside en la comparación de odontogramas impresos o digitalizados, aunque se ha cuestionado cierta subjetividad al asentar dicha información. Los recursos imagenológicos constituyen una evidencia más confiable y objetiva, reduciendo el sesgo iden-tificatorio. La obtención de radiografías post mor-tem (PM) reproduciendo en lo posible las técnicas que han generado las imágenes ante mortem (AM) recuperadas, otorga una eficaz modalidad compa-rativa, aumentando su valor probatorio. Materiales y Métodos: Se efectuó la comparación entre radio-grafías panorámicas y periapicales tomadas a 10 pacientes atendidos en un consultorio particular de la ciudad de Quilmes, Provincia de Buenos Aires, don-de se visualizaban tratamientos de endodoncia. Los registros de ambas técnicas de imágenes se realiza-ron sobre los mismos sujetos entre los años 2010 y 2022. Se cotejaron 11 radiografías periapicales y 10 panorámicas, procediéndose a la digitalización de la totalidad de la muestra. Se clasificaron las imágenes de cada persona conforme a la fecha de obtención de las mismas. A las más antiguas se las catalogó con el color verde, representando el material AM, mien-tras que las más recientes se marcaron en color rojo, constituyendo la información PM. Resultados: Teniendo en cuenta los criterios estipulados por la Junta Americana de Odontología Forense (ABFO) se identificaron positivamente 7 casos estudiados, 2 fueron catalogados como identificación posible, en tanto que 1 se clasificó como insuficiente. No se re-gistraron exclusiones. Conclusión: Los tratamientos endodónticos podrían suministrar información pon-derable en procesos de identificación humana en virtud de la escasa probabilidad de sufrir alteracio-nes morfológicas y estructurales por su estratégica localización intradentaria, otorgando posibilidades concretas de establecer la identidad categórica de sujetos desconocidos (AU)

Introduction: Identification by comparison of dental records represents a scientifically consolidated methodology. The most common strategy lies in the comparison of printed or digitised odontograms, although certain subjectivity has been questioned when recording said information. Imaging resources constitute more reliable and objective evidence, reducing identification bias. Obtaining post-mortem (PM) radiographs reproducing the techniques that have generated the recovered ante-mortem (AM) images, provides an effective comparative modality, increasing its evidentiary value. Materials and Methods: A comparison was made between panoramic and periapical radiographs taken to 10 patients treated in a private office in the city of Quilmes, Province of Buenos Aires, where endodontic treatments were visualized. The records of both imaging techniques were carried out on the same subjects between 2010 and 2022. 11 periapical and 10 panoramic radiographs were collected, and the entire sample was digitized. The images of each person were classified according to the date they were obtained. The oldest ones were cataloged with the color green, representing the AM material, while the most recent ones were marked in red, constituting the PM information. Results: Taking into account the criteria stipulated by the American Board of Forensic Odontology (ABFO), 7 cases studied were positively identified, 2 were classified as possible identification, while 1 was classified as insufficient. No exclusions were recorded. Conclusion: Endodontic treatments could provide valuable information in human identification processes due to the low probability of suffering morphological and structural alterations due to their strategic intradental location, providing concrete possibilities of establishing the categorical identity of unknown subjects (AU)

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Abstract Objective: To evaluate the utility of panoramic radiographs in pre-prosthetic screening of edentulous arches. Material and Methods: Panoramic radiographs taken for three years were retrospectively analyzed. Observations from the radiographs shall be categorized and classified into either of the two categories, namely: 'findings with minimal impact on denture fabrication' and 'findings which affect denture fabrication and require further evaluation.' Anatomic variations, jaw pathologies, and residual ridge resorption patterns were assessed. Results: This study included the initial screening of 23,020 panoramic radiographs, out of which 505 (showing either one or both edentulous arches) were included for the study purpose. The age range of the subjects was from 21 to 94 years. 52.6% of the radiographs showed positive findings. More than half of the radiographs belonged to the males (52.5%). Hyperpneumatization of the maxillary sinus, crestal position of the mental foramen, and retained root fragments were the most common entities noted in the radiographs. Changes in the mental foramen were significantly higher in males than females (p=0.002). Conclusion: Observations from this study showed that panoramic radiographs have high utility for screening edentulous arches, and they should be used in routine clinical practice before denture fabrication.

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Exposure to ionizing radiation is an occupational risk for veterinarians due to the potential for carcinogenesis, reproductive disorders, cataracts, and hereditary genetic changes. This survey study aimed to identify the radiological protection practices routinely used by veterinarians who work with portable digital X-ray equipment in horses in Brazil and assess their knowledge regarding current legislation. A total of 120 voluntary participation questionnaires were sent to veterinarians who used portable digital radiographic equipment in horses nationwide. The frequencies of the answers were analyzed using the chi-square test and logistic regression models. Thirty-five veterinarians responded (29% response rate). Of these, there was a greater participation of professionals in public institutions (40%, 14/35, p < .001), with 69% from the southeast region (24/35, p < .001) and 69% (24/35, p = .028) being male. We found that self-employed veterinarians had a higher odds ratio (OR) (9.00; 95% confidence interval (CI) [1.39-58.44]; p = .021) of not using personal protective equipment compared with those in professional public institutions. In addition, not knowing the current legislation Collegiate Directorate Resolution 611/22 was a potential risk factor for lower radiological protection (OR, 8.00; 95% CI, [0.79-81.33]; p = 0.079). In conclusion, findings indicated that Brazilian equine veterinarians generally do not adopt adequate radiological protection against ionizing radiation during radiographic examinations and have low knowledge of the current legislation. Results can be used as background for the formulation of specific radiation protection guidelines for veterinarians and incentive educational and training strategies to reduce risks inherent to occupational exposure.

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BACKGROUND: The management of acromioclavicular (AC) joint dislocation remains controversial. Recently, anatomic coracoclavicular (CC) fixation with a double clavicular tunnel and three flip-buttons has shown promising results. This study aimed to evaluate functional and radiological outcomes in patients with high-grade AC joint dislocation treated with anatomic CC fixation using double clavicular tunnels and three flip-buttons. METHODS: A retrospective, unicentric study was performed. The study included patients with high-grade AC joint dislocation who underwent surgery with anatomic CC fixation using double clavicular tunnels and three flip-buttons. Demographic data were obtained from medical records. A functional evaluation using subjective shoulder value (SSV), visual analog scale (VAS), and disabilities of the arm, shoulder, and hand (DASH) questionnaires was performed, and an evaluation of preoperative and postoperative comparative Zanca view images was performed. Factors associated with functional outcomes and radiological AC reduction were analyzed. RESULTS: A total of 83 patients completed follow-up and were included in the analysis. The mean SSV, VAS, and DASH scores were 92.8, 0.8, and 6.4, respectively. Patients who had complications experienced significantly worse functional outcomes (DASH: P=0.037). Suboptimal final AC reduction was observed in nine patients (11.1%), and significantly more frequently in patients older than 40 years (P=0.031) and in surgeries performed more than 7 days after injury (P=0.034). There were two reoperations (2.4%). CONCLUSIONS: Anatomic CC fixation with a double clavicular tunnel and three flip-buttons leads to good functional outcomes, low complication rates, and high rates of optimal AC reduction. Level of Evidence: Level IV; Case series.

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En Cuba, el primer departamento de rayos X se inauguró en el año 1907 por Francisco Domínguez Roldán. Poco se divulga un contacto previo durante el siglo XIX, en la guerra hispano-norteamericana. Este artículo describe el uso de los rayos X en la guerra hispano-cubano-norteamericana y su importancia en la historia de la Radiología. Para esta contienda, la parte norteamericana preparó sus barcos hospitales. El ejército habilitó el Relief y el Missouri, mientras que la marina lo hizo con Solace. También se convirtieron en buques hospitales el Olivette y el Bay State. Todos contaban con equipos de rayos X. El capitán Borden publicó un libro en 1900 "El uso de los rayos Roentgen por el departamento médico de la armada estadounidense en la guerra con España (1898)" que marcó un antes y un después en el uso de los rayos X. Este fue un hecho trascendental para la historia de la Radiología y favoreció un avance considerable en la sanidad militar y civil.

In Cuba, the first X-ray department was set up in 1907 by Francisco Domínguez Roldán. Little is reported about a previous contact during the 19th century in the Spanish-Cuban-American war. This article describes the use of X-rays in the Spanish-Cuban-American war and its importance in the history of Radiology. For this war the American side prepared its hospital ships. The Army fitted out the Relief and the Missouri, while the Navy did it with the Solace. The Olivette and the Bay State also became hospital ships. All were equipped with X-ray equipment. Captain Borden published a book in 1900 "The Use of Roentgen Rays by the Medical Department of the U.S. Navy in the War with Spain (1898)" which marked a before and after in the use of X-rays. This was a transcendental fact for the history of Radiology and favored a considerable advance in military and civilian health.

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Abstract The study aimed to assess the influence of excessive use of a photostimulable phosphor plate (PSP) on the density, image noise, and contrast of radiographs. For that, radiographs of an acrylic block were acquired with a PSP of the Express intraoral system to assess the density and image noise. Initially, five images were obtained and exported (first group). After 400 exposures to X-rays and scannings of PSP, other five images were obtained and exported (second group). The same procedure was done after 800 (third group), 1200 (fourth group), 1600 (fifth group), and 2000 acquisitions (sixth group), resulting in 30 images to be evaluated. The mean and standard deviation of the gray values were calculated for the images using the ImageJ software. For contrast analysis, radiographs of an aluminum step-wedge were acquired with a new PSP following the same acquisition intervals. The percentage of contrast variation was calculated. Another two unused PSP receptors were employed to evaluate the method's reproducibility. The comparison of the results among the acquisition groups was performed with one-way Analysis of Variance (α=0.05). Intraclass Correlation Coefficient (ICC) assessed the reproducibility of the receptors. Image noise did not differ among the groups (p>0.05). There was a slight increase in density after 400 acquisitions and a slight difference in contrast for all acquisition groups without a pattern of increase or decrease (p<0.05). ICC showed excellent reliability for the methods. Therefore, excessive PSP use slightly affected the radiograph's density and contrast.

Resumo Objetivou-se avaliar a influência do uso excessivo de uma placa de fósforo fotoestimulável (PSP) na densidade, ruído e contraste das radiografias. Foram adquiridas radiografias de um bloco de acrílico com uma PSP do sistema intraoral Express para avaliar a densidade e o ruído da imagem. Inicialmente, cinco imagens foram obtidas e exportadas (primeiro grupo). Após 400 exposições aos raios X e escaneamentos, outras cinco imagens foram obtidas e exportadas (segundo grupo). O mesmo procedimento foi feito após 800 (terceiro grupo), 1200 (quarto grupo), 1600 (quinto grupo) e 2000 aquisições (sexto grupo), resultando em 30 imagens a serem avaliadas. A média e o desvio padrão dos valores de cinza foram calculados para as imagens usando o software ImageJ. Para análise de contraste, foram adquiridas radiografias de uma escala de alumínio com uma nova PSP seguindo os mesmos intervalos de aquisição. A porcentagem de variação do contraste foi calculada. Outras duas PSP sem uso prévio foram utilizadas para avaliar a reprodutibilidade dos métodos. A comparação dos resultados entre os grupos de aquisição foi realizada pela Análise de Variância one-way (α=0,05). O Coeficiente de Correlação Intraclasse (ICC) avaliou a reprodutibilidade dos receptores. O ruído da imagem não diferiu entre os grupos (p>0,05). Houve um leve aumento na densidade após 400 aquisições e uma pequena diferença no contraste para todos os grupos de aquisição sem padrão de aumento ou diminuição (p<0,05). O ICC mostrou excelente confiabilidade para os métodos. Portanto, o uso excessivo da PSP afetou levemente a densidade e o contraste radiográfico.

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INTRODUCTION: The aim of this study was to comparatively evaluate the learning outcomes achieved by first-year radiography students educated with either virtual reality (VR) simulation training or physical simulation training. The implementation of VR has been proposed to enhance learning in radiography students and provide a more effective and efficient approach to simulation. However, the learning outcomes achieved with this approach have not been widely investigated. METHODS: Through stratified randomisation, 188 radiography students were allocated to one of two matched groups: a VR group (using Virtual Medical Coaching's Radiography simulation) and a physical simulation group (using Philips' X-ray equipment). Both groups were taught 31 radiography views over one 25-week semester. Both groups were assessed in an Objective Structured Clinical Examination (OSCE), using actors as patients in a physical X-ray environment. Assessment was conducted by assigning objective count scores for five assessment criteria. RESULTS: The VR group achieved shorter OSCE duration and fewer errors in moving equipment and patient positioning: these results were statistically significant (P < 0.00). There was no significant difference in the frequency of errors in radiographic exposure setting between the VR and the physical simulation group. The current findings concur with the limited number of published studies concerning VR simulation in radiography. CONCLUSIONS: The results of this study demonstrated superior effectiveness and efficiency in the VR group. This provides preliminary evidence to introduce VR simulation in the host institution and provide evidence that it may be possible to replace the use of physical simulation across other years of the degree. Further research investigating these possibilities is warranted.

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This paper introduces a novel computational method to simulate and predict radiation dose profiles in a water phantom irradiated by X-rays of 6 and 15 MV at different depths and field sizes using Artificial Neural Networks within the error margin required by the code of practice 398 of the International Atomic Energy Agency (IAEA). Our method uses deep-learning Artificial Neural Networks as an alternative to the Monte Carlo methods usually used nowadays. It reproduces the radiation dose profiles for X-rays of 6 and 15 MV data reported in the British Journal of Radiology (Aird, 1996). Even more, our method reproduces data from other sources with acceptable errors. These simulations pave the way to enhance radiotherapy techniques in planning patient doses and calibrating ionizing radiation measurement instruments used in the fight against cancer.

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The placement of large bore double-lumen catheters for hemodialysis (HD) is one of the most frequent procedures performed in HD patients. However, these procedures are associated with complications, the most common being catheter malposition. In this context, catheter deviation to the left superior intercostal vein (LISV) is a very uncommon malposition, which must be differentiated from intrathoracic extravascular catheter lodgment. We report a case of an adult male patient on hemodialysis who presented with a thrombosed arteriovenous fistula and requiring urgent HD. His past medical history included hemophilia, allergy to contrast media, and multiple previous central vein catheterizations. A non-tunneled HD catheter was placed without any difficulty in the left internal jugular vein. However, the arterial lumen failed to pull any blood with free flow in the venous lumen. A chest X-ray revealed a surprising finding. The malpositioned catheter was removed successfully without any complications.

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Las malformaciones arteriovenosas pulmonares (MAVP) consisten en comunicaciones directas entre el sistema arterial y el sistema venoso pulmonar, sin paso de la sangre por el lecho capilar, produciéndose un cortocircuito de derecha a izquierda extracardíaco, pueden ser congénitas o adquiridas. Algunos casos pueden ser asintomáticos, en cambio en otros pueden ocasionar diversas manifestaciones clínicas y se pueden asociar a complicaciones severas. En niños se observa una baja incidencia y son más frecuentes las formas congénitas. La MAVP se debe sospechar por las manifestaciones clínicas y las imágenes de la radiografía de tórax (RxTx) y su confirmación se realiza mediante una AngioTomografía Computada (TC) de tórax. La embolización endovascular es actualmente el tratamiento de elección, con excelentes resultados, aunque requiere de un seguimiento posterior y de un operador experimentado. Reportamos el caso de una niña que ingresó con clínica muy sugerente, incluyendo: disnea, acropaquia, cianosis periférica, e hipoxemia refractaria. Sin embargo, inicialmente el cuadro clínico fue confundido con una crisis asmática. La Angio-TC de tórax confirmó el diagnóstico y el tratamiento mediante embolización endovascular resultó exitoso.

Pulmonary arteriovenous malformations (PAVM) are communications between the arterial and the pulmonary venous system, without passage of blood through the capillary bed, causing a left to right extracardiac shunt. Some cases may be asymptomatic, while others may cause various clinical manifestations and may be associated with severe complications. In children a low incidence is observed, and congenital forms are more frequent. PAVM should be suspected by clinical manifestations and chest x-ray imaging and confirmed by chest Computed Tomography Angiography (CTA). Endovascular embolization is currently the treatment of choice, with excellent results, although it requires subsequent follow-up. We report a patient who was admitted with a very suggestive clinical history, including: dyspnea, clubbing, peripheral cyanosis, and severe hypoxemia, refractory to oxygen therapy. However, initially the clinical picture was confounded with an asthmatic crisis. CTA confirmed the diagnosis and treatment by endovascular embolization was successful.

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Purpose: The development of a robust model for automatic identification of COVID-19 based on chest x-rays has been a widely addressed topic over the last couple of years; however, the scarcity of good quality images sets, and their limited size, have proven to be an important obstacle to obtain reliable models. In fact, models proposed so far have suffered from over-fitting erroneous features instead of learning lung features, a phenomenon known as shortcut learning. In this research, a new image classification methodology is proposed that attempts to mitigate this problem. Methods: To this end, annotation by expert radiologists of a set of images was performed. The lung region was then segmented and a new classification strategy based on a patch partitioning that improves the resolution of the convolution neural network is proposed. In addition, a set of native images, used as an external evaluation set, is released. Results: The best results were obtained for the 6-patch splitting variant with 0.887 accuracy, 0.85 recall and 0.848 F1score on the external validation set. Conclusion: The results show that the proposed new strategy maintains similar values between internal and external validation, which gives our model generalization power, making it available for use in hospital settings. Supplementary Information: The online version contains supplementary material available at 10.1007/s12553-022-00704-4.

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SUMMARY OBJECTIVE: This study aimed to investigate the relationship between the presence of hip osteoarthritis and the neutrophil-lymphocyte ratio, platelet-lymphocyte ratio, monocyte-lymphocyte ratio, and neutrophil-monocyte ratio. METHODS: Participants with hip osteoarthritis and healthy controls aged 45-75 years were recruited in the study. The participants with hip osteoarthritis were divided into two groups: mild/moderate hip osteoarthritis and severe hip osteoarthritis. Complete blood parameters of the participants were recorded, and neutrophil-lymphocyte ratio, neutrophil-monocyte ratio, monocyte-lymphocyte ratio, and platelet-lymphocyte ratio were calculated. Pain severity was evaluated using a visual analog scale. RESULTS: A total of 76 participants with hip osteoarthritis and 59 healthy controls were included in the study. The mean age of the participants was 57.6±6.11 years. Mean neutrophil-lymphocyte ratio and neutrophil-monocyte ratio values were statistically significantly different between the hip osteoarthritis group and healthy control group (p<0.05). Platelet-lymphocyte ratio, monocyte-lymphocyte ratio, erythrocyte sedimentation rate, and C-reactive protein values were not significantly different between the groups. Also, there was no difference between all inflammatory parameters and hip osteoarthritis severity (p>0.05). CONCLUSIONS: Neutrophil-lymphocyte ratio and neutrophil-monocyte ratio values were higher in patients with hip osteoarthritis than in healthy controls. Mean platelet-lymphocyte ratio, monocyte-lymphocyte ratio, erythrocyte sedimentation rate, and C-reactive protein values did not change according to the presence of hip osteoarthritis. Not all hematological indices give valuable information regarding the severity of hip osteoarthritis.

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X-ray image of the hand is the most used technique to estimate bone age in children. For the analysis of bone mineral density using DXA in children, bone age may help to adjust such measurement in some cases. During image acquisition in DXA, an anteroposterior image of the hand may be acquired and used to evaluate bone age but few studies have evaluated the agreement between conventional X-ray and DXA images. The aim of the study was to determine bone age estimation agreement between conventional X-ray images and DXA in children and adolescents aged 5 to 16 years of age. We performed an analytical cross-sectional study of 711 healthy subjects. Subject´s bone age, both in conventional X-ray, and DXA images were read independently by two expert evaluators blinded for chronological age. Intraobserver and inter-observer reproducibility were evaluated using Intraclass Correlation Coefficient (ICC), and the agreement between bone age estimations made by both evaluators was analyzed using ICC and Bland-Altman analysis. General agreement between techniques measured through ICC was 0.99 with a mean difference of 6 months between techniques being older the ages obtained by DXA. The agreement limits were around ±2 years, which means that 95% of all differences between techniques were covered within this range. We found a high level of ICC agreement in bone age readings from X-ray and DXA images although we observed overestimation of bone age measurements in DXA. Differences between techniques were greater in women than in men, especially at the ages corresponding to puberty. Bone age measurement in DXA images appears not to be reliable; hence it should be suggested to perform conventional radiography of the hand to assess bone age taking into account that X-ray images have better resolution.

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