DICOM file format has better radiographic image quality than other file formats: an objective study

Abstract This study aimed to assess the influence of the file format on the image quality parameters (image noise, brightness, and uniformity) of periapical radiographs acquired with different digital systems. Radiographic images of an acrylic phantom were acquired with two digital systems - Digora Toto and Express, and exported into five different file formats - TIFF, BMP, DICOM, PNG, and JPEG. Image noise, image brightness (mean of gray values), and image uniformity (standard deviation of gray values) were evaluated in all images. A two-way analysis of variance with Tukey's test as a post-hoc test was used to compare the results, considering the file formats and radiographic systems as the studied factors. A significance level of 5% was adopted for all analyses. The DICOM image file format presented lower image noise, higher brightness (higher mean gray values), and greater image uniformity (p<0.001) than the other file formats, which did not differ from each other for both digital radiography systems (p>0.05). The Express system revealed lower image noise and greater image uniformity than the Digora Toto system regardless of the image file format (p<0.001). Moreover, the Express showed higher brightness than the Digora Toto for all image file formats (p<0.001), except for the DICOM image file format, which did not significantly differ between the digital radiography systems tested (p>0.05). The DICOM image file format showed lower image noise, higher brightness, and greater image uniformity than the other file formats (TIFF, BMP, PNG, and JPEG) in both digital radiography systems tested.

Resumo Este estudo teve como objetivo avaliar a influência do formato do arquivo nos parâmetros de qualidade de imagem (ruído de imagem, brilho e uniformidade) de radiografias periapicais adquiridas com diferentes sistemas digitais. As imagens radiográficas de um fantoma de acrílico foram adquiridas com dois sistemas digitais - Digora Toto e Express, e exportadas em cinco formatos de arquivo diferentes - TIFF, BMP, DICOM, PNG e JPEG. O ruído da imagem, o brilho da imagem (média dos valores de cinza) e a uniformidade da imagem (desvio padrão dos valores de cinza) foram avaliados em todas as imagens. A análise de variância (ANOVA) bidirecional com o teste post-hoc de Tukey foi aplicada para comparar os resultados, considerando os formatos de arquivo e os sistemas radiográficos como os fatores estudados. Um nível de significância de 5% foi adotado para todas as análises. O formato de arquivo de imagem DICOM apresentou menor ruído de imagem, maior brilho (maiores valores médios de cinza) e maior uniformidade de imagem (p<0,001) do que os outros formatos de arquivo, que não diferiram entre si para ambos os sistemas de radiografia digital (p>0,05). O sistema Express apresentou menor ruído de imagem e maior uniformidade de imagem que o sistema Digora Toto, independentemente do formato do arquivo de imagem (p<0,001). Além disso, o Express mostrou maior brilho do que o Digora Toto para todos os formatos de arquivo de imagem (p<0,001), exceto para o formato de arquivo de imagem DICOM, que não diferiu significativamente entre os sistemas de radiografia digital testados (p>0,05). O formato de arquivo de imagem DICOM mostrou menor ruído de imagem, maior brilho e maior uniformidade de imagem do que os outros formatos de arquivo (TIFF, BMP, PNG e JPEG) em ambos os sistemas de radiografia digital testados.

Consideraciones teóricas sobre la radiografía digital como medio diagnóstico / Theoretical considerations on digital radiography as a diagnostic mean i: en

Durante las últimas décadas el proceso de obtención de imágenes médicas digitales ha avanzado tecnológicamente, de tal modo que estas se han vuelto indispensables en el reconocimiento de numerosas enfermedades y en la aplicación de diferentes terapéuticas; sin embargo, la implementación de la radiología digital constituye un reto para los profesionales de esta rama que no posean una completa preparación, por lo que es necesario desarrollar estrategias coherentes para facilitar su uso. En este trabajo se ofrecen algunas consideraciones teóricas sobre la radiografía digital como medio diagnóstico, lo cual supone un cambio en el ejercicio de los profesionales de esta especialidad, quienes requieren actualizar sus conocimientos en relación con esta técnica, con el fin de perfeccionar su desempeño y establecer diagnósticos certeros que conduzcan a tratamientos eficaces, y así lograr el bienestar y la calidad de vida de la población.

During the last decades the process of obtaining digital medical images has advanced technologically, in such a way that they have become indispensable in the recognition of numerous diseases and in the application of different treatments; however, the implementation of digital radiography constitutes a challenge for professionals in this branch who do not have a complete training, so it is necessary to develop coherent strategies to facilitate its use. This paper offers some theoretical considerations about digital radiography as a diagnostic means, which implies a change in the practice of professionals in this specialty, who need to update their knowledge in relation to this technique, in order to get better their performance and establish accurate diagnoses that lead to effective treatments, and thus achieve the welfare and quality of life in the population.

Influencia de la Morfología Externa de la Raíz de Primeros Premolares Superiores en la Sobreestimación del Espesor Radiográfico Radicular Durante la Preparación para Poste, Evaluados Mediante Tomografía Computarizada Cone Beam / Influence of the External Morphology of the Root of Upper First Premolars on the Overestimation of Radiographic Root Thickness During Post Preparation, Evaluated by Cone Beam Computed Tomography

La investigación tuvo como objetivo determinar la influencia de la morfología externa de la raíz de primeros premolares superiores en la existencia de sobreestimación radiográfica durante la preparación para poste. Con este fin se realizó un estudio transversal in vitro, donde 60 premolares superiores uniradiculares fueron instrumentadas con fresas Gates Glidden y Pesso de calibre 1, 2 y 3. Seguidamente se obtuvieron imágenes radiográficas digitales de cada pieza dentaria mediante un aparato posicionador a una distancia constante en sentido vestíbulo lingual, asimismo se realizaron imágenes tomográficas volumétricas de las muestras. En ambas técnicas imagenológicas se midió el espesor a mesial y distal de las piezas. La sobreestimación fue calculada mediante la diferencia de la medida tomográfica menos la radiográfica. Los resultados indicaron que en ambas paredes radiculares hubo diferencia significativa entre las medidas radiográficas y tomográficas (p<0,05), encontrándose en la pared distal diferencias altamente significativas (p<0,001); además se evidenció que la sobreestimación radiográfica fue mayor en la pared distal. El estudio concluyó que existe sobreestimación radiográfica en premolares superiores durante la preparación para poste de un 20,42 % en promedio, siendo la pared distal la estructura que presenta mayor sobreestimación.

SUMMARY: he investigation´s objective was to determine the influence of external morphology of the root of upper first premolars in the existence of radiographic overestimation during preparation for post. An in vitro cross-sectional study was carried out, where 60 single-rooted upper premolars were instrumented with burs. Gates Glidden and Pesso of caliber 1, 2 and 3, then, digital radiographic images of each dental piece were obtained by means of a positioning device at a constant distance in the buccolingual direction; volumetric tomographic images of the samples were also performed. In both imaging techniques, the mesial and distal thickness of the pieces was measured. The overestimation was calculated by the difference of the tomographic measurement minus the radiographic one. The results indicated that in both root walls there was a significant difference between the radiographic and tomographic measurements (p<0.05), with highly significant differences being found in the distal wall (p<0.001); In addition, it was evidenced that the radiographic overestimation was greater in the distal wall. The study concluded that there is radiographic overestimation in upper premolars during post preparation of 20.42% on average, with the distal wall being the structure that presents the greatest overestimation.

Could the radiographic image quality be affected by the excessive use of the photostimulable phosphor plate?

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.

Clinical analysis of 56 cases of occupational pulmonary thesaurosis induced by dust of iron and its compounds / 中国职业医学

Objective: To analyze the clinical characteristics and imaging features of occupational pulmonary thesaurosis induced by dust of iron and its compounds (OPTIDIC). Methods: A total of 230 cases of occupational welder's pneumoconiosis (OWP) patients or observation subjects were selected as the research subjects using the retrospective analysis method. They were diagnosed in four occupational disease diagnosis institutions in Shandong Province from 2010 to 2017. The high kV X-ray chest radiography or chest digital radiograph (hereinafter referred to as X-ray) were re-read to screen OPTIDIC patients. The clinical data of OPTIDIC patients were collected and analyzed. Results: Among the 230 cases, 56 cases were diagnosed as OPTIDIC, accounting for 24.3%. The clinical symptoms of the 56 patients with OPTIDIC were cough, sputum, chest tightness, shortness of breath, and difficulty breathing, while their physical signs were low or coarse breath sounds in lungs and others. Most of the X-ray results showed p shadows or q shadows, accounted for 98.2%, of which p/p shadow and q/q shadow accounted for 62.5%. The result of chest computed tomography (CT) showed diffuse point/round shadow and diffuse glass shadow in OPTIDIC patients. The result of fibro-bronchoscopy showed that a large amount of iron lutein particles was accumulated in macrophages and biopsy of lung showed idiopathic pulmonary hemosiderosis in OPTIDIC patients. Conclusion: The clinical characteristics of OPTIDIC patients showed no different from OWP. However, the result of X-ray of OPTIDIC patients mainly showed small circular shadows, and their CT images mainly showed diffuse point/round shadows or grinding glass shadow, which could be used to the differential diagnosis of OPTIDIC and OWP.

Relación entre el diagnóstico histopatológico de sacos foliculares de terceros molares y la medida radiográfca estandarizada en radiografía panorámica digital / Relationship between histopathologic diagnosis of third molar follicular sacs and standardized radiographic measurement on digital panoramic radiography

Objetivo: establecer la relación entre el diagnóstico histopatológico de sacos foliculares de terceros molares y la medida radiográfca estandarizada en radiografía panorámica digital. Métodos: se llevó a cabo un estudio descriptivo en el que se incluyeron 28 sacos foliculares de terceros molares. Dos observadores midieron la radiolucidez pericoronal en radiografías panorámicas digitales usando un método estandarizado y se calculó el índice de correlación intraclase. Se estableció un diagnóstico radiográfco según la medida del saco, con <2.5 mm como el límite para sacos foliculares normales. Dicho diagnóstico fue comparado con el respectivo diagnóstico histopatológico. Se calculó sensibilidad y especifcidad; se aplicó la prueba de chi-cuadrado, exacta de Fisher y, fnalmente, el índice Kappa. Resultados: se obtuvo un alto grado de acuerdo entre los observadores. La prueba radiográfca tuvo una baja sensibilidad (0.27) y especifcidad (0.6) y no se encontró diferencia estadísticamente signifcativa entre estos. Conclusiones: la ausencia de hallazgos radiográfcos no implica ausencia de enfermedad. Además, no se puede establecer relación entre la presencia de quistes dentígeros y radiolucidez ≥ 2.5 mm en radiografía panorámica digital.

Objective: To establish the relationship between the histopathological diagnosis of follicular sacs of third molars and the standardized radiographic measurement in digital panoramic radiography. Methods: This was a descriptive study in which 28 follicular sacs of third molars were included. In digital panoramic radiographs two observers measured the pericoronal radiolucency using a standardized method and the intraclass correlation index was calculated. A radiographic diagnosis was established according to the size of the sac, with <2.5mm being the limit for normal follicular sacs. This diagnosis was compared with the respective histopathological diagnosis. Sensitivity and specifcity were calculated; the chi-square test, Fisher's exact test and fnally the Kappa index were applied. Results: A high degree of agreement was obtained among the observers. The radiographic test had a low sensitivity (0.27) and specifcity (0.6) and no statistically signifcant diference was found between these. Conclusions: The absence of radiographic fndings does not imply absence of disease, furthermore, no relationship can be established between the presence of dentigerous cysts and radiolucency ≥ 2.5 mm in digital panoramic radiography.

How is the use of digital dental radiology in a developing country? An overview of Brazil / ¿Cómo es el uso de la radiología dental digital en un país en vías de desarrollo? Una visión general de Brasil

Abstract The aim of this study was to assess the use of digital dental radiology in Brazil, by focusing on the use of image receptors, imaging exams and digital image enhancement tools, also assessing the methods of professional image transfer. Questionnaires were distributed in person on dental meetings and digitally via messaging (WhatsApp®) and mailings list. The sample of this cross-sectional study consisted of 478 questionnaires. Most participants were woman (n=315, 65.9%), with average age of 33.8±9.2 years. Descriptive and frequency analysis was performed. Chi-square and Fisher's exact tests were used (α=0.05). Most dentists worked at shared dental clinics (34.7%) and use digital image receptors (51.1%), but a representative percentage (48.9%) still exclusively use radiographic films. Photostimulable phosphor plate is the most used digital image receptor. Among extraoral exams, panoramic radiography (PAN) is the most used. Regarding dental specialties, oral radiologists and oral and maxillofacial surgeons mostly use cone-beam computed tomography (p<0.001). Most dentists who use digital systems make use of digital image enhancement tools (87.8%), mainly contrast, zoom, brightness and measurements. The most common method of professional image transfer (professional-professional and professional-patiens) is by email, with few dentists using online app and social media (26%). Therefore, while most Brazilian dentists use digital imaging systems, a significant percentage still exclusively use radiographic films. The most extraoral imaging exams used is PAN. Regarding image enhancement tools, brightness and contrast adjustments, zoom and measurements are the most applied. Finally, dentists generally use email for professional image transfer.

Resumen El objetivo de este estudio fue evaluar uso de la radiología dental digital en Brasil, centrándose en uso de receptores de imagen, exámenes de imágenes y herramientas de mejora de imagen digital, evaluando también los métodos de transferencia de imagen profesional. Cuestionarios se distribuyeron de forma presencial en reuniones odontológicas y de forma digital a través de mensajería (WhatsApp®) y lista de correo. Muestra de este estudio transversal estuvo compuesta por 478 cuestionarios. Mayoría de los participantes eran mujeres (n=315, 65,9%), con edad promedio de 33,8±9,2 años. Se realizó un análisis descriptivo y de frecuencias. Se utilizaron las pruebas Chi-cuadrado y exacta de Fisher (α=0,05). La mayoría de los odontólogos trabajaban en clínicas dentales compartidas (34,7%) y utilizan receptores de imágenes digitales (51,1%), pero un porcentaje representativo (48,9%) todavía utiliza exclusivamente películas radiográficas. Placa de fósforo fotoestimulable es el receptor de imagen digital más utilizado. Entre los exámenes extraorales, la radiografía panorámica (PAN) es la más utilizada. En cuanto a las especialidades odontológicas, los radiólogos orales y los cirujanos orales y maxilofaciales utilizan mayoritariamente la tomografía computarizada de haz cónico (p<0,001). Mayoría de los odontólogos que utilizan sistemas digitales utilizan herramientas de mejora de imagen digital (87,8%), principalmente contraste, zoom, brillo y medidas. Método más común de transferencia de imágenes profesionales (profesional-profesional y profesional-pacientes) es por correo electrónico, con pocos dentistas que utilizan aplicaciones en línea y redes sociales (26%). Por lo tanto, mientras que la mayoría de dentistas brasileños utilizan sistemas de imágenes digitales, un porcentaje significativo aún utiliza exclusivamente películas radiográficas. Examen de imagen extraoral más utilizado es el PAN. En cuanto a las herramientas de mejora de imagen, los ajustes de brillo y contraste, el zoom y las medidas son las más aplicadas. Finalmente, los dentistas generalmente usan el correo electrónico para la transferencia de imágenes profesionales.

Reference value of surface radiation dose of digital radiography among adults in Beilun District / 预防医学

Objective@#To investigate the reference level of surface radiation dose of digital radiography (DR) among adult examinees in Beilun District, Ningbo City, so as to provide insights into the optimization of the parameters of DR systems and rational management of the radiation dose.@*Methods@#Based on the cloud imaging system covering 14 DR systems in 11 public hospitals in Beilun District, the diagnosis of adults receiving DR and DR systems check were collected from May 2020 to April 2021. The air kerma-area product ( PKA ) was selected as a measure, and the local diagnostic reference level ( LDRL ), the regional median dose ( RMD ), the regional lowest dose predicted level ( LDPL ) and the typical dose in the DR imaging room were defined using the quartile method according to the examination site, projection direction and radiography positions. The PKA value was transformed into incident air kerma ( Ka, e ), and compared with the recommended value in the Requirements for Radiological Protection in Diagnostic Radiology ( GBZ 130-2020 ).@*Results@#DR was performed among 133 065 person-times from May 2020 through April 2021 in Beilun District. The greatest RMD was found on abdomen AP DR in the supine position ( 120 μGy·m2 ), and the lowest RMD was seen on chest PA DR in the standing position ( 17 μGy·m2 ). The maximums of typical dose in the DR imaging room on chest PA ( 33 vs. 30 μGy·m2 ), abdomen AP ( 161 vs. 153 μGy·m2 ) and pelvis AP DR ( 164 vs. 162 μGy·m2 ) were greater than LDRL in the supine position, and the minimums of typical dose on chest PA ( 10 vs. 11 μGy·m2 ) and chest LAT DR ( 33 vs. 34 μGy·m2 ) were lower than LDPL in the standing position. Following transformation into Ka, e, the LDRL ranged from 0.27 to 3.80 mGy, and the maximums of typical dose ranged from 0.25 to 3.55 mGy, which was much lower than the recommended dose proposed in the national criteria.@*Conclusions@#The reference level of surface radiation dose of DR is established among adults in Beilun District, which is lower than the recommended dose in the national criteria of China. Such a reference level may be employed by medical institutions for optimization of the parameters of DR systems. Key words： digital radiography radiation dose diagnostic reference level air kerma-area product

Investigation on medical radiation protection of medical and health institutions in Tibet Autonomous Region, 2020 / 中国职业医学

@#Abstract: Objective （ ） To investigate the current status of medical radiation protection in medical and health institutions MHI Methods - （ ） in Tibet Autonomous Region. Sixty one MHIs in seven prefectures cities of Tibet Autonomous Region were selected as the study subjects by stratified random sampling. The radiological protection equipment and personal protective ， equipment were investigated and the quality control of radiological equipment and radiation protection monitoring in Results ， radiological workplace were monitored. There were 368 radiation workers in 61 MHI institutions accounting for 4.8% （ ） ∶ ， 368/7 701 of the total number of radiation workers. The ratio of male to female was 2 1 and the average was six people/ institution. The quantity of radiation monitoring equipment and personal protective equipment at all levels of MHI was less than ， 1.00 sets/person. Among them tertiary MHI had the lowest number of personal protective equipment configurations. The （ monitoring qualified rates of radiation equipment quality control and radiation protection in radiation workplace were 73.3% 88/ ） （ ）， 120 and 95.8% 115/120 respectively. The lowes tmonitoring qualified rate of radiation equipment quality control was 55.2% （ ） ， （ ， ）Conclusion 32/58 with digital radiography and the second was computed tomography 84.8% 28/33 . The monitoring ， qualified rate of radiation protection in MHI workplaces at all levels in Tibet Autonomous Region is high. However radiation monitoring equipment and personal protective equipment should be increased.

Logistic regression model-based analysis of influencing factors of initial testing qualified rate of condition monitoring of digital radiography devices in China / 中华放射医学与防护杂志

Objective:To analyze the influencing factors on initial testing qualified rate of condition monitoring of digital radiography (DR) devices in China and provide the scientific basis for key points of national medical radiation protection monitoring work.Methods:The data of quality control detection of DR devices, reported by 31 provinces in 2020, were collected from National Radiation Health Information Platform-National Medical Radiation Protection Monitoring System. Logistic regression was used to analyze the related influencing factors of initial testing qualified rate of condition monitoring of DR devices.Results:The result of logistic regression analysis showed that the nature of radiological health technical service institutions, the level of medical and health institution and the regions where they are located in China were the independent influencing factors of initial testing qualified rate of condition monitoring of DR devices ( χ2=15.41-21.18, P < 0.05). Private institution group ( OR=1.714, 95% CI: 1.310-2.243), tertiary hospital group ( OR=1.710, 95% CI: 1.310-2.232) and secondary hospital group ( OR=1.540, 95% CI: 1.203-1.971) had a higher qualified probability of DR devices, while western region group ( OR=0.670, 95% CI: 0.526-0.852) had a lower qualified probability of DR devices. Conclusions:Supervision on quality control of DR devices should be strengthened, such as strengthening the random inspection and double-check to the devices. And great attention should be paid to the quality control testing of DR devices in the western China and in the primary and ungraded hospitals.

Energy-Dispersive X-Ray Spectrometry Analysis and Radiopacity of Five Different Root Canal Sealers

Abstract Root canal sealers should have optimum adhesion to the root dentin, low cytotoxicity, sufficient radiopacity and high dimensional stability, which depend mainly on their chemical composition. The aims of this study were to evaluate the chemical composition of Syntex (Cerkamed, Stalowa Wola, Poland), Adseal (Meta Biomed, Cheongju-si, Korea), Sealapex (SybronEndo, Scafati, Italy), MTA Fillapex (Angelus, Londrina, Brazil) and GuttaFlow Bioseal (Coltene/Whaledent, Altstätten, Switzerland) and to determine their radiopacity comparatively. Stainless steel molds with an inner diameter of 5 mm and a depth of 2 mm were constructed. Tested root-canal sealers were mixed and poured into the molds. Following setting, digital periapical radiographs of the specimens (n=12) were taken under standard exposure conditions and the mean gray-values of specimens were measured using a computer graphics program. Then the specimens were examined by scanning electron microscopy, and Energy-dispersive X-ray analysis was performed. The data were analyzed using One-way ANOVA followed by Holm-Sidak multi-comparison test (p = 0.05). Sealapex showed higher calcium peak than MTA Fillapex, GuttaFlow Bioseal, Adseal and Syntex sealers. MTA Fillapex contained a highest amount of tungstate. Sealapex presented the highest radiopacity value among the tested materials (p < 0.05), whereas MTA Fillapex was the least radiopaque material (p < 0.05). Each root canal sealer contains different compositions of radiopacifiers including bismuth oxide, calcium tungstate and zirconium oxide. The tested root canal sealers had radiopacity values above the ISO-specified limit. Sealapex was the most radiopaque root canal sealer followed by GuttaFlow Bioseal, Syntex, Adseal and MTA Fillapex.

Resumo Os cimentos endodônticos devem conter ótima adesão à dentina radicular, baixa citotoxicidade, radiopacidade suficiente e estabilidade dimensional elevada, que dependem principalmente da sua composição química. Os objetivos deste estudo foram avaliar a composição química de Syntex (Cerkamed, Stalowa Wola, Polônia), Adseal (Meta Biomed, Cheongju-si, Coreia), Sealapex (SybronEndo, Scafati, Itália), MTA Fillapex (Angelus, Londrina, Brasil) e GuttaFlow Bioseal (Coltene/Whaledent, Altstätten, Suíça) e determinar comparativamente a sua radiopacidade. Foram construídos moldes de aço inoxidável com um diâmetro interior de 5 mm e uma profundidade de 2 mm. Os cimentos testados foram misturados e vertidos em moldes. Após a fixação, foram feitas radiografias periapicais digitais dos espécimes (n=12) em condições de exposição padrão e os valores médios de cinza dos espécimes foram medidos utilizando um programa de computação gráfica. Em seguida, as amostras foram examinadas por microscopia eletrônica de varredura, e foi realizada uma análise de raios X dispersiva de energia. Os dados foram analisados utilizando a ANOVA unidirecional seguida do teste de comparação múltipla Holm-Sidak (p = 0,05). O Sealapex mostrou um pico de cálcio mais elevado do que os cimentos MTA Fillapex, GuttaFlow Bioseal, Adseal e Syntex. O MTA Fillapex continha uma quantidade mais elevada de tungstato. O Sealapex apresentou o maior valor de radiopacidade entre os materiais testados (p < 0,05), enquanto que a MTA Fillapex foi o material menos radiopaco (p < 0,05). Cada cimento endodôntico contém diferentes composições de radiopacificadores incluindo óxido de bismuto, tungstato de cálcio e óxido de zircônio. Os cimentos testados apresentaram valores de radiopacidade acima do limite especificado pela ISO. Sealapex foi o cimento obturador mais radiopaco seguido por GuttaFlow Bioseal, Syntex, Adseal e MTA Fillapex.

Comparación entre trazados cefalométricos manual y digital en radiografías laterales del cráneo / Comparison between Manual and Digital Cephalometric Tracing in Side Radiographies of the Skull

Resumen Objetivo: Evaluar la diferencia del trazado cefalométrico manual con el digital en radiografías laterales de cráneo. Materiales y métodos: Inicialmente se realizó un piloto para calibrar al investigador principal, en donde se analizaron 10 radiografías pertenecientes a cinco pacientes del Servicio de Radiología del Centro Odontológico de nuestra institución para evaluar la concordancia entre los dos evaluadores y establecer el tamaño de la muestra. Finalmente, se analizaron 78 radiografías cefalométricas de 39 pacientes, en las que se realizó el trazado cefalométrico de Steiner manual y digital. Esas radiografías se analizaron en una escala 1:1 y posteriormente se evaluó la diferencia de las mediciones mediante el análisis univariado, se determinó en mediana e intervalo intercuartil por separado. En el análisis bivariado, se aplicó la prueba de signo de rangos de Wilcoxon y muestras pareadas para determinar la diferencia de las mediciones cefalométricas de Steiner entre el tipo del análisis cefalométrico. El nivel de significancia se fijó en p < 0,05 y confiabilidad al 95%, respectivamente. Resultados: No hubo diferencia significativa en la mayoría de las mediciones hechas de manera manual y digital, siendo el ángulo interincisal la única medición angular en la cual hubo diferencia significativa al obtener un resultado de p = 0,002. Mientras tanto, en las mediciones lineales, la única medición en la que hubo diferencia significativa fue en el segmento incisivo inferior - NB con p = 0,005. Conclusión: No se encuentran diferencias significativas entre el trazado cefalométrico manual y el digital. No obstante, es importante tener en cuenta que la muestra o población evaluada es reducida para definir conclusiones.

Abstract Objective: To evaluate the difference of the manual cephalometric tracing with the digital tracing on lateral cranial radiographs. Materials and Methods: Initially, a pilot study was carried out to calibrate the principal investigator, where 10 radiographs belonging to 5 patients of the Radiology Service of the Dental Center, were analyzed to evaluate the intraclass concordance between the two evaluators. To establish the size of the sample, finally, 78 cephalometric radiographs of 39 patients were analyzed, in which the manual and digital Steiner cephalometric tracing was performed. These radiographs were analyzed on a 1: 1 scale and then the difference of the measurements was evaluated using the univariate analysis, which was determined in the median and interquartile range, separately. In the bivariate analysis, the Wilcoxon rank sign test and paired samples were applied to determine the difference of Steiner's cephalometric measurements between the cephalometric analysis type. The level of significance was set at p < 0.05 and 95% reliability, respectively. Results: There was no significant difference in most of the measurements made manually and digitally. The interincisal angle the only angular measurement in which there was a significant difference when obtaining a result of p = 0.002, while, in the linear measurements, the only measurement in which there was significant difference was in the lower incisor segment - NB with p = 0.005. Conclusion: There is no significant difference between manual and digital cephalometric tracing, nevertheless it is important to keep in mind that the simple or population evaluated is reduced to define conclusions.

Progress in imaging diagnosis of pneumoconiosis / 预防医学

@#Pneumoconiosis is a serious occupational disease in China. Early imaging examination is one of the important measures for the diagnosis, treatment and prevention of pneumoconiosis. Digital radiography (DR) and computed tomography (CT) play an important role in the screening and diagnosis of pneumoconiosis, as well as the recent rise of artificial intelligence (AI) technology. This paper reviews the latest progress in technical parameter debugging and quality control of DR, optimization of AI computer-aided system and CT-aided diagnosis of pneumoconiosis, summarizes the advantages and problems in the application of the three technologies, providing research directions for imaging diagnosis of pneumoconiosis.

Knowledge level of Iranian dental practitioners towards digital radiography and cone-beam computed tomography / Nível de conhecimento de dentistas Iranianos sobre Radiografia Digital e Tomografia Computadorizada de Feixe Cônico

Objective: TThis study aimed to assess the knowledge level of Iranian dental practitioners about digital radiography (DR) and cone-beam computed tomography (CBCT). Material and Methods: In this cross-sectional study, a researcher-designed questionnaire was administered among 180 general dentists and specialists. The questionnaire had three main domains of demographic information, fifteen questions about knowledge of DR (advantages, disadvantages, physical properties) and twenty six questions about knowledge of CBCT (indications, applications, advantages, route of knowledge acquisition). Data were analyzed using descriptive statistics, t-test and Pearson's correlation coefficient. Results: Of 180 participants, 76 (42.2%) were females. The minimum, maximum and mean± standard deviation scores obtained in DR were 4, 14, and 9.031 ± 1.85 and in CBCT were 0,26 and 18.56 ± 4.81, respectively. In the CBCT domain, the participants had maximum knowledge about "low radiation dose" (72.8%) and minimum knowledge about the "role of CBCT in determination of bone density" (45%). In DR domain, the participants had maximum knowledge about "no need for radiographic films" (75.6%) and minimum knowledge about "not requiring manual processing" (15.6%). Overall, participants had higher level of knowledge about CBCT than DR. An inverse correlation was noted between age and work experience with the number of correct answers. However, no significant difference was noted in the knowledge level of males and females regarding CBCT or DR (p = 0.233 and p = 0.227, respectively). Conclusions: further education seem imperative for dentists in this respect for more efficient diagnosis and treatment planning, minimize patient radiation dose and save time and cost. (AU)

Objetivos: Avaliar o nível de conhecimento de dentistas iranianos sobre radiografia digital (RD) e tomografia computadorizada de feixe cônico (TCFC). Materiais e métodos: Neste estudo transversal, um questionário, elaborado por pesquisadores, foi aplicado a 180 dentistas clínicos geral e especialistas. O questionário tinha três domínios principais de informação demográfica, quinze questões sobre conhecimento de RD (vantagens, desvantagens, propriedades físicas) e vinte e seis questões sobre conhecimento de CBCT (indicações, aplicações, vantagens, protocolo de aquisição). Os dados foram analisados por meio de estatística descritiva, teste t e coeficiente de correlação de Pearson. Resultados: Dos 180 participantes, 76 (42,2%) eram do sexo feminino. Os escores mínimo, máximo e média ± desvio padrão obtidos na RD foram 4, 14 e 9,031 ± 1,85 e na CBCT foram 0, 26 e 18,56 ± 4,81, respectivamente. No domínio CBCT, os participantes tinham conhecimento máximo sobre "baixa dose de radiação" (72,8%) e conhecimento mínimo sobre o "papel da CBCT na determinação da densidade óssea" (45%). No domínio RD, os participantes possuíam conhecimento máximo sobre "não há necessidade de filmes radiográficos" (75,6%) e conhecimento mínimo sobre "não requer processamento manual" (15,6%). No geral, os participantes tinham maior nível de conhecimento sobre CBCT do que RD. Foi observado correlação inversa entre idade e experiência de trabalho com o número de acertos. No entanto, nenhuma diferença significativa foi observada no nível de conhecimento de homens e mulheres sobre TCFC ou RD (p = 0,233 e p = 0,227 respectivamente). Conclusão: Parece imperativo para os dentistas iranianos, mais educação nesse aspecto para diagnóstico e planejamento de tratamento mais eficientes, minimizar a dose de radiação para paciente, economizar tempo e custos. (AU)

Knowledge, Attitude, and Practice, about Digital and Conventional Radiographs among General Dentists and Specialists in Kanchipuram District

Radiographs are an important tool in maximizing oral health care. During initial years, the film based radiographic images were used, as technological advancements progressed, digital radiographic imaging has become an indispensable tool in diagnosis. The aim of the present study is to evaluate the practice of digital and conventional radiographs, and radiation safety among dental practitioners. METHODSA questionnaire descriptive study was conducted, including general dental practitioners and dental specialists in Kanchipuram district. The questionnaire comprised of 12 questions that were distributed through Google forms, email and responses were collected. The questions were based on their preference about digital or conventional radiographs, reason for their preference, satisfaction with diagnostic quality, patient compliance, and their radiation protection practice. RESULTSA total of 200 dental practitioners in Kanchipuram district was given questionnaires. All of them answered the questionnaire. 148 were males and 52 were females. The age distribution was between 26 - 33 years. 65 % of the practitioners answered that they use digital radiographs often owing to less time consumption and ease of storage, 90 % of them answered that their diagnostic quality is improved by using digital radiographs, of which 51 % use radiation protection and 39 % of their patients use radiation protection during exposure. CONCLUSIONSThis era is moving towards digital radiography, among the ones who are using it, most of them are satisfied with it. Attitude towards radiation protection and hazards has to be improved amongst dental practitioners. The use of digital radiography is increasing among dental practitioners due to its less radiation exposure, improved diagnostic quality, ease of access and as it is less time consuming. The need for availability of standard improved quality of care equally raises the point for cost effective methods for the developing technologies.

Osteocondromatosis múltiple. Caso clínico / Multiple osteochondromatosis. Clinical case / Osteocondromatose múltipla. Caso clínico

RESUMEN Introducción: la osteocondromatosis múltiple hereditaria, entidad autosómica dominante, que se caracteriza por el crecimiento de múltiples tumores benignos llamados osteocondromas. Presentación del caso: paciente femenina de 12 años de edad, que acude a consulta refiriendo dolor constante en rodilla derecha, más acentuado con la marcha. Examen físico SOMA: Aumento de volumen de rodilla derecha hacia sus caras externas e internas con dolor a la palpación, se palpa masa dura, no movible, de bordes irregulares. También se constatan tumoraciones de similares características en ambos hombros y rodillas. Discusión: se le realizan radiografías, observando lesiones óseas en la metáfisis proximal de ambos húmeros a predominio derecho. Exostosis a nivel de metáfisis proximal y distal de ambos fémures, en tibia y peroné bilateral. En rodilla derecha se observa crecimiento hacia la línea media de la tumoración del peroné desplazando en valgo la metáfisis proximal de la tibia. Conclusiones: se plantea una exostosis múltiple como diagnóstico. Se realizó tratamiento quirúrgico escisión tumoral del extremo proximal del peroné de la rodilla derecha y de la cara interna de la metáfisis proximal de la tibia y biopsia que confirmó el diagnóstico.

ABSTRACT Introduction: hereditary multiple osteochondromatosis, an autosomal dominant entity, characterized by the growth of multiple benign tumors called osteochondromas. Case presentation: 12-year-old female patient, who comes to the consultation referring to constant pain in the right knee, more accentuated with the gait. PHYSICAL exam SOMA: Increase of volume of right knee towards their outer and inner faces with pain to palpation, it palps hard mass, not movable, of irregular edges. Tumors of similar characteristics are also found in both shoulders and knees. Discussion: X-rays are performed, observing bone lesions in the proximal metaphysis of both humeruses to right predominance. Exostosis at the level of proximal and distal metaphysis of both femurs, in tibia and bilateral fibula. In the right knee, growth is observed towards the midline of the fibula tumor displacing the proximal metaphysis of the tibia in valgo. Conclusions: Multiple exostosis is raised as a diagnosis. Surgical treatment was performed tumor excision of the proximal end of the fibula of the right knee and the inner face of the proximal metaphysis of the tibia and biopsy that confirmed the diagnosis.

RESUMO Introdução: osteocondromatose múltipla hereditária, uma entidade autossômica dominante, caracterizada pelo crescimento de múltiplos tumores benignos chamados osteochondromas. Apresentação do caso: paciente do sexo feminino de 12 anos, que chega à consulta referindo-se a dores constantes no joelho direito, mais acentuadas com a marcha. Exame FÍSICO SOMA: Aumento do volume do joelho direito em direção aos seus rostos externos e internos com dor à palpação, palpa massa dura, não móvel, de bordas irregulares. Tumores de características semelhantes também são encontrados em ambos os ombros e joelhos. Discussão: São realizados raios-X, observando lesões ósseas na metafise proximal de ambos os úmeros à predominância direita. Exostose ao nível de metafísica proximal e distal de ambos os fêmures, natíbia e fíbula bilateral. No joelho direito, observa-se crescimento para a linha média do tumor de fíbula deslocando a metafísica proximal da tíbia em valgo. Conclusões: A exostose múltipla é levantada como diagnóstico. Foi realizado tratamento cirúrgico excisão tumoral da extremidade proximal da fíbula do joelho direito e da face interna da metafise proximal da tíbia e biópsia que confirmou o diagnóstico.

Application of deep residual neural network in detecting small bowel obstruction by abdominal plain film / 西安交通大学学报(医学版)

Objective: To study whether a deep residual neural network can detect small bowel obstruction patterns on upright abdominal radiographs. Methods:The data of training set and test set used in this study were obtained from The First Affiliated Hospital of Xi'an Jiaotong University and No.215 Hospital of Shaanxi Nuclear Industry; the data of validation set came from No.215 Hospital of Shaanxi Nuclear Industry. Totally 3 298 clinical upright abdominal radiographs obtained from two hospitals were classified into obstructive and non-obstructive categories independently by two radiologists on the basis of the four signs on upright abdominal radiographs, who discussed and reached consensus when disagreements arose. Among them, 569(17.3%) images were found to be consistent with small bowel obstruction, and 2 729 (82.7%) images had no small bowel obstruction. A total of 2 305 training sets and 993 test sets (training set: test set = 2.3:1) were composed of data from the two groups, including 405 cases (17.6%) of small bowel obstruction, 1 900 cases (82.4%) of non-small bowel obstruction, 164 cases (16.5%) of small bowel obstruction, and 829 cases (83.5%) of non-small bowel obstruction. The diagnosis of small bowel obstruction in training and testing sets was based on experienced radiologists' evaluation. Totally 861 abdominal upright abdominal radiographs constituted the validation set (99 with small bowel obstruction and 762 with no small bowel obstruction); the surgical results and clinical diagnosis were set as the gold standard. In this study, the image 2012 large-scale visual recognition challenge data set (ILSVRC2012) was used for pre-training the deep residual neural network (ResNet38). The retraining of deep residual network (ResNet38) with training set data was used to establish the diagnostic model. The test set was mainly used in the learning algorithm process to adjust the algorithm parameters to modify the network, so as to make the network model more efficient. Results: After training, the deep residual neural network achieved an AUC of 0.83 on the test set (95% CI 0.82-0.92). The sensitivity of the system for small bowel obstruction was 84.1%, with a specificity of 65.0%. And on validation set it achieved an AUC of 0.87 (95% CI 0.82-0.92), the sensitivity of the system for small bowel obstruction was 89.9%, with a specificity of 68.0%. Conclusion: Transfer learning with deep residual neural network may be used to train a detector for small bowel obstruction on upright abdominal radiographs even with limited training data.

Application value of computer-aided diagnosis in diagnosing pneumoconiosis / 中国职业医学

OBJECTIVE: To explore the application value of computer-aided diagnosis technology based on deep residual network in the diagnosis of occupational pneumoconiosis(hereinafter referred to as pneumoconiosis). METHODS: A total of 5 424 digital radiography chest images were collected from occupational health examiners using a convenient sampling method.These images were used to establish a data set. After training with the data set, the pneumoconiosis computer-aided diagnosis system was used to independently diagnose the test set images(50 positive and negative cases each) and output a positive probability value. Six diagnostic physicians with varied ages and different experiences performed independent diagnosis on the test set and assisted diagnosis with reference to computer results. The diagnostic accuracy was evaluated using the area under the receiver operating characteristic curve(AUC) value, sensitivity, and specificity.The Kappa consistency test was used to evaluate the diagnostic consistency. RESULTS: The AUC value, sensitivity, specificity, and Kappa value of pneumoconiosis diagnosis increased after using computer-aided diagnosis. The sensitivity increased from 0.74 to 0.85(P<0.05)and the Kappa value increased from 0.64 to 0.79(P<0.05). The AUC value increased from 0.90 to 0.95, and the specificity increased from 0.89 to 0.94, but there were no statistical difference(P<0.05). CONCLUSION: Computer-aided diagnosis can improve the sensitivity and consistency of pneumoconiosis screening and reduce the differences in diagnosis among physicians.

Radiopacidad de Cementos de Resina Compuesta Evaluados con Técnica Radiográfica Digital / "Radiopacity of Resin Cements Evaluated with Digital Radiographic Technique"

RESUMEN: Objetivo: comparar la radiopacidad de distintos cementos de resina y corroborar si cumplen con los requisitos de normativas ISO. Material y método: Se prepararon muestras de 1 mm de grosor de los cementos de resina: RelyX U200 (3M ESPE), Calibra (Dentsply Sirona), Calibra Universal (Dentsply Sirona) y Bifix SE (VOCO). Las muestras fueron radiografiadas junto a una cuña de aluminio escalonada. Las imágenes fueron analizadas para determinar el valor en escala de grises y su respectivo valor en mm de Al. Los datos fueron analizados para comparar la radiopacidad de los materiales entre sí y con los requisitos establecidos por normas ISO. Resultados: La radiopacidad equivalente en mm de Al en orden descendiente fue de 2,84 ± 0,18 para Calibra, 2,37 ± 0,15 para Bifix SE, 2,26 ± 0,14 para Calibra Universal y de 1,67 ± 0,07 para RelyX U200. Estos valores son todos mayores al mismo grosor de aluminio exigido por la norma ISO 4049. Se establecieron diferencias estadísticamente significativas entre los cementos. Conclusiones: Se determinó que existen diferencias en la radiopacidad entre los cementos de resina compuesta estudiados. Sin embargo, todos los cementos evaluados cumplen con la norma ISO-4049 de radiopacidad.

ABSTRACT: Objective: Compare the radiopacity of different resin cements and verify their compliance with the requirements of ISO regulations. Material and method: Samples -10 mm in diameter and 1 mm thickness- of the resin cements RelyX U200 (3M ESPE), Calibra (Dentsply Sirona), Universal Calibra (Dentsply Sirona) and Bifix SE (VOCO) were prepared. Radiographies of the samples with a stepped aluminum wedge were obtained. For each sample, the grayscale and mm of Al values were calculated. The data were analyzed to compare the radiopacity of the materials and to contrast them with the requirements established by ISO standards. Results: The equivalent radiopacity in mm of Al in descending order was 2.84 ± 0.18 for Calibra, 2.37 ± 0.15 for Bifix SE, 2.26 ± 0.14 for Calibra Universal and 1.67 ± 0.07 for RelyX U200. These values exceed the value required by ISO 4049 standard. Statistically significant differences were established between the cements. Conclusion: There are differences in the radiopacity of the resin cements studied. However, all the cements complied with ISO 4049 radiopacity standards.

Myelography in calves: a comparative study between the contrast agents iopamidol and iohexol / Mielografia em bezerros: estudo comparativo entre os meios de contrastes iopamidol e ioexol

Due to the scarcity of myelogenous studies in cattle, the present study aimed to evaluate the efficacy and distribution of iopamidol and iohexol contrast agents in calves, in order to determine guidelines for obtaining diagnostic radiographs of spinal cord disorders in these animals. Ten healthy Holstein calves, seven days to two months of age, were divided into two groups, according to the contrast medium applied. Myelographic studies of the spine were performed with the calves in lateral recumbency, with radiographs repeated 20 times during a two-hour period. On the radiographs, the contrast medium was analyzed for opacity, detail of the image, distension of the medullary canal, and progression of the contrast line. After seven days, the myelographic studies were repeated, with the contrast media exchanged between the groups. There were no significant differences in the quality of the images and speed of the spinal column filling between the two contrast media. Furthermore, the best quality radiographic images were obtained six to eight minutes after injection of the contrast in the cervical spinal segment, 80 minutes in the thoracic, and 20 minutes in the lumbar, sacral, and cauda equina segments.(AU)

Devido à escassez de estudos mielográficos em bovinos e relatos de complicações no procedimento, o presente estudo teve por objetivo avaliar a eficácia e a distribuição dos meios de contraste iopamidol e ioexol em bezerros, a fim de nortear a melhor conduta para o diagnóstico de afecções vertebrais e medulares nesses animais. Foram utilizados 10 bezerros Holandeses, hígidos, com idade entre sete dias e dois meses, distribuídos em dois grupos, conforme o meio de contraste aplicado. O estudo mielográfico da coluna vertebral foi realizado na posição laterolateral, repetido em 20 momentos, durante o período de duas horas. Nas radiografias, analisou-se o meio de contraste quanto à opacidade, detalhes da imagem, distensão do canal medular e progressão da linha de contraste. Após sete dias, foi realizado o segundo período experimental, que compreendeu a troca do meio de contraste dentro de cada grupo. Não houve diferenças significativas em relação à qualidade da imagem e à velocidade do preenchimento da coluna medular entre os dois meios de contraste. A partir da administração dos meios de contraste, a obtenção de imagens radiográficas de melhor qualidade deu-se após seis a oito minutos no segmento medular cervical, 80 minutos no torácico e 20 minutos nos segmentos lombar, sacral e cauda equina.(AU)