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Background.Anecdotal reports are appearing in the scientific literature about cases of brain tumors in interventional physicians who are exposed to ionizing radiation. In response to this alarm, several designs of leaded caps have been made commercially available. However, the results reported on their efficacy are discordant.Objective.To synthesize, by means of a systematic review of the literature, the capacity of decreasing radiation levels conferred by radiation attenuating devices (RADs) at the cerebral level of interventional physicians.Methodology.A systematic review was performed including the following databases: MEDLINE, SCOPUS, EBSCO, Science Direct, Cochrane Controlled Trials Register (CENTRAL), WOS, WHO International Clinical Trials Register, Scielo and Google Scholar, considering original studies that evaluated the efficacy of RAD in experimental or clinical contexts from January 1990 to May 2023. Data selection and extraction were performed in triplicate, with a fourth author resolving discrepancies.Results.Twenty articles were included in the review from a total of 373 studies initially selected from the databases. From these, twelve studies were performed under clinical conditions encompassing 3801 fluoroscopically guided procedures, ten studies were performed under experimental conditions with phantoms, with a total of 88 procedures, four studies were performed using numerical calculations with a total of 63 procedures. The attenuation and effectiveness of provided by the caps analyzed in the present review varying from 12.3% to 99.9%, and 4.9% to 91% respectively.Conclusion.RAD were found to potentially provide radiation protection, but a high heterogeneity in the shielding afforded was found. This indicates the need for local assessment of cap efficiency according to the practice.

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OBJECTIVES: The aim of this systematic review was to verify the accuracy of linear measurements performed on low-dose CBCT protocols for implant planning, in comparison with those performed on standard and high-resolution CBCT protocols. METHODS: The literature search included four databases (Pubmed, Web of Science, Embase, and Scopus). Two reviewers independently screened titles/abstracts and full texts according to eligibility criteria, extracted the data, and examined the methodological quality. Risk of bias assessment was performed using the Quality Assessment Tool For In Vitro Studies. Random-effects meta-analysis was used for pooling measurement error data. RESULTS: The initial search yielded 4684 titles. In total, 13 studies were included in the systematic review, representing a total of 81 samples, while 9 studies were included in the meta-analysis. The risk of bias ranged from medium to low. The main results across the studies indicate a strong consistency in linear measurements performed on low-dose images in relation to the reference methods. The overall pooled planning measurement error from low-dose CBCT protocols was -0.24 mm (95% CI, -0.52 to 0.04) with a high level of heterogeneity, showing a tendency for underestimation of real values. Various studies found no significant differences in measurements across different protocols (eg, voxel sizes, mA settings, or dose levels), regions (incisor, premolar, molar) and types (height vs. width). Some studies, however, noted exceptions in measurements performed on the posterior mandible. CONCLUSION: Low-dose CBCT protocols offer adequate precision and accuracy of linear measurements for implant planning. Nevertheless, diagnostic image quality needs must be taken into consideration when choosing a low-dose CBCT protocol.

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Introducción. Las radiografías continúan usándose ampliamente, subestimando los riesgos. Esto sucede, especialmente, en las unidades de cuidado neonatal, lo que implica que los neonatos reciben una dosis de radiación ionizante mayor que los adultos. Objetivo. Cuantificar las dosis de radiación recibidas al tomar radiografías y evaluar los posibles factores asociados con el aumento de la dosis. Materiales y métodos. Se llevó a cabo un estudio observacional de 160 neonatos de la Unidad de Recién Nacidos del Hospital Universitario San Ignacio, Bogotá, Colombia. Se consideró como variable dependiente la dosis de entrada en piel por cada radiografía. Se hizo la caracterización de los pacientes, seguida de un análisis multivariado con regresión lineal múltiple para identificar factores asociados. Resultados. Se analizaron 160 pacientes y 492 radiografías en total. Entre los hallazgos más frecuentes, se encuentran: pacientes de sexo masculino (n=87; 54,4 %), nacimiento por cesárea (n=122; 76,3 %) e indicación de toma de radiografías por dificultad respiratoria (n=123; 24,9 %). El 1,8 % (n=9) de los pacientes no tenían una indicación para la toma de la radiografía. La radiografía más frecuente fue la de tórax (n=322; 65,4 %). La mayoría de las radiografías se tomaron con el equipo computarizado (n=352; 71,5 %) y no con el digital (n=140, 28,4 %). La mediana de la dosis de entrada en piel con el equipo computarizado fue de 0,112 mGy (0,022; 0,134 mGy) y, con el equipo digital, de 0,020 mGy (0,019, 0,022 mGy). Conclusiones. Se cuantificaron las dosis de radiación absorbida en neonatos, general y específica, con el equipo computarizado y el digital. Se identificaron mayores dosis con el equipo computarizado. Se reconoció la interacción entre el equipo computarizado con menores edades gestacionales corregidas como principal factor para el aumento de la dosis. Además, se reconoció la relación entre el equipo computarizado y una menor edad gestacional corregida, como principal factor para una mayor dosis.

Introduction. Radiographs are still widely used, underestimating the risks. This situation is frequent in neonatal care units, generating radiation doses than in adults. Objective. To quantify the received radiation doses when performing radiographs on neonates and the possible factors associated with higher doses. Materials and methods. We performed an observational study of 160 neonates from the newborn unit of the Hospital Universitario San Ignacio, Bogotá, Colombia. We considered the input dose of each radiograph as the dependent variable. Patients were characterized and a multivariate analysis with multiple linear regression was performed to identify associated factors. Results. We analyzed 160 newborns and 492 radiographs. The most frequent findings were male patients (n=87, 54.4%), cesarean delivery (n=122, 76.3%), and radiograph indication for respiratory distress (n=123, 24.9%). One-point eight percent of the patients (n=9) did not have radiograph indication. The most frequently taken radiograph was chest (322, 65.4%). Most radiographs were taken with a computerized equipment (n=352, 71.5%), compared to a digital one (n=140, 28.4%). The median input dose with computerized equipment was 0.112 mGy (0.022, 0.134 mGy), and with the digital equipment was 0.020 mGy (0.019, 0.022 mGy). Conclusions. The general and specific absorbed radiation doses were measured in neonates with a computerized and a digital equipment. We identified higher doses with the computerized equipment. In addition, it was recognized the correlation between computerized radiography equipment with lower corrected gestational ages as the main factor for dose increase.

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In dental practice, the use of imaging has increased over the years, generating an increase in the radiation dose for the dental patient. One factor under discussion is the amount of dose used in patients, men, women and children, at different stages of their life, due to the scientific evidence of the harmful effects of ionizing radiation. This review of the literature analyzed the characteristics of radiation and its effects in relation to the doses administered, and its equivalences in dental practice in panoramic periapical radiographs and cone beam tomographies. A search of the literature was carried out in the main information sources such as Medline (via PubMed), SEVIER, SCIELO, and LILACS, using the search terms with a date limitation of the last 10 years. The selected articles had to include information regarding the keywords used, including "Dental Offices, Radiation Dose, X-Rays, Ambulatory Care."

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RESUMEN Fundamento: aún no existe una forma óptima para determinar la dosis absorbida por los tumores; este desconocimiento es la causa de que la dosis final del tratamiento sea impredecible. Por esta causa los pacientes pueden estar recibiendo dosis mayores que las mínimas requeridas para su correcto diagnóstico. Objetivo: crear un código fuente para un proyecto de aplicación del programa GATE en la simulación de la dosis absorbida en radioterapia molecular, por método Montecarlo, para un maniquí de Giap. Métodos: se realizó la simulación por método de Montecarlo a partir de modelar el maniquí de Giap, mediante la plataforma de simulación GATE. Se compararon los resultados obtenidos con la información reflejada en la bibliografía sobre las mejores prácticas estandarizadas. Resultados: se confeccionó un código fuente implementado en GATE para la determinación de la dosis absorbida en radioterapia molecular. Se obtuvo distribución no uniforme de dosis en un medio de actividad uniforme y un 2 % de incertidumbre aproximado (en buena correspondencia con los valores reportados en la literatura), los resultados permiten afirmar que la simulación de dosis por medio de la plataforma GATE es confiable, de poco gasto computacional y altamente recomendable. Conclusiones: es recomendable utilizar la plataforma GATE para la simulación del cálculo de la dosis absorbida por ser rápida, de bajo costo computacional y confiable.

ABSTRACT Background: there is still no optimal way to determine the dose absorbed by tumors; this lack of knowledge is the reason why the final dose of treatment is unpredictable. For this reason, patients may be receiving doses greater than the minimum required for their correct diagnosis. Objective: to create a source code for an application project of the GATE program in the simulation of absorbed dose in molecular radiotherapy, by Monte Carlo method, for a Giap phantom. Methods: the simulation was carried out by the Montecarlo method from modeling the Giap phantom, using the GATE simulation platform. The results obtained were compared with the information reflected in the bibliography on standardized best practices. Results: a source code implemented in GATE was prepared for the determination of the absorbed dose in molecular radiotherapy. Non-uniform distribution of doses was obtained in a medium with uniform activity and an approximate 2% uncertainty (in correspondence with the values reported in the literature), the results allow to affirm that the dose simulation through the GATE platform is reliable, of little computational expense and highly recommended. Conclusions: it is advisable to use the GATE platform for the simulation of the calculation of the absorbed dose because it is fast, of low computational cost and reliable.

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RESUMEN Fundamento: los estudios híbridos producen una dosis total de radiación que es resultado de la dosis proveniente del radiofármaco y la emitida por la tomografía computarizada, por eso la optimización es indispensable. Objetivo: evaluar la relación de la dosis de tomografía computarizada con algunos parámetros de calidad de la imagen en protocolos de estudios híbridos. Métodos: para evaluar la calidad de la imagen se emplearon los maniquíes de Catphan y de Livermore en 12 protocolos preestablecidos de un equipo de tomografía por emisión del fotón único Mediso. Los datos de los descriptores de dosis de cada estudio se obtuvieron del cabezal DICOM. Se compararon los parámetros de calidad de imagen clásicos como ruido y la MTF 50 % para el maniquí de Catphan, y otros como la relación contraste ruido, el promedio de números de Hounsfield y su desviación estándar en las regiones de interés de los órganos correspondientes, en el maniquí de Livermore. Se analizó la relación de estos parámetros de calidad con los descriptores de dosis de los diferentes protocolos. Resultados: los parámetros relacionados con la calidad en el maniquí de Catphan no mostraron diferencias significativas (p<0,05) entre los diferentes protocolos para estudios híbridos. Se encontraron diferencias significativas entre los protocolos clínicos con diferentes calidades y el protocolo clínico estándar, para el maniquí antropomórfico, en la desviación estándar de los números de Hounsfield y en la relación contraste ruido (p<0,05). Conclusiones: el estudio de la relación contraste ruido y la desviación de los números de tomografía computarizada en las regiones de interés pueden servir de parámetro cuantitativo para la optimización de dosis en escenario clínico.

ABSTRACT Background: hybrid studies produce a total radiation dose that is the result of the dose imparted by the radiopharmaceutical and that emitted by the computed tomography, therefore optimization is essential. Objective: to evaluate the relationship of the computed tomography dose with some image quality parameters in hybrid study protocols. Methods: to evaluate the image quality, the Catphan and Livermore Phantom were used in 12 pre-established protocols of a Mediso single photon emission tomography equipment. The data for the dose descriptors for each study were obtained from the DICOM head. The classic image quality parameters such as noise and the MTF 50% for the Catphan manikin, and others such as the contrast-noise ratio, the average of Hounsfield numbers and their standard deviation in the regions of interest of the corresponding organs were compared, in Livermore's mannequin. The relationship of these quality parameters with the dose descriptors of the different protocols was analyzed. Results: the quality-related parameters in the Catphan manikin did not show significant differences (p <0.05) between the different protocols for hybrid studies. Significant differences were found between the clinical protocols with different qualities and the standard clinical protocol, for the anthropomorphic manikin, in the standard deviation of the Hounsfield numbers and in the contrast-to-noise ratio (p <0.05). Conclusions: the study of the contrast noise ratio and the deviation of the computed tomography numbers in the regions of interest can serve as a quantitative parameter for the optimization of doses in the clinical setting.

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Objectives.To optimize the absorbed organ dose in relation to the field of view for temporomandibular joint examinations in four cone beam computed tomography devices.Methods.An anthropomorphic adult head and neck phantom, and 192 LiF dosimeters (TLD-100) were used. The dosimeters were placed in the region corresponding to the lens, parotid glands, submandibular glands, and thyroid. Small, medium and large FOVs were selected on Orthopantomograph OP300 Maxio, PaX-i3D Smart, ORTHOPHOS XG, and i-CAT Next Generation device when it was possible.Results.A wide range of absorbed dose values was recorded for all organs due to the different exposure parameters of each device. The radiosensitive organ with the highest dose was the parotid glands. The devices with 5 × 5 cm FOV recorded a lower dose in this protocol, while for the device without a small FOV (≤5 × 5 cm), the lowest dose was observed with the large FOV (6 × 16 cm).Conclusions.We recommend a double exposure with an FOV of 5 × 5 cm in the OP300 Maxio, PaX-i3D Smart, and ORTHOPHOS XG device, while in the i-CAT Next Generation device, a single exposure FOV of 6 × 16 cm is indicated.

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BACKGROUND: Computed tomography (CT) accounts for 13% of all radiological examinations in the United States and 40-70% of the radiation that patients receive. Even with the advent of magnetic resonance imaging (MRI), CT continues to be the gold standard for diagnosing bone fractures. There is uncertainty as to whether CT with a low radiation dose has a fracture detection rate similar to that of standard-dose CT. OBJECTIVE: To determine the detection rate of low-dose radiation CT and standard-dose radiation CT for fractures, in patients with suspected fractures. DESIGN AND SETTING: Systematic review of comparative studies on diagnostic accuracy within the evidence-based health program at a federal university in São Paulo (SP), Brazil. METHODS: We searched the electronic databases Cochrane Library, MEDLINE, EMBASE and LILACS up to June 29, 2020, for studies evaluating the detection rates of low-dose CT and standard-dose CT for diagnosing bone fractures. The Research Triangle Institute (RTI) item bank tool was used for methodological quality evaluation. RESULTS: The fracture detection rate according to the number of bones evaluated, using CT with low-dose radiation was 20.3%, while with standard-dose radiation it was 19.2%, and the difference between the methods was not significant. The fracture detection rate according to the number of patients, using CT with low-dose radiation was 56.0%, while with standard-dose radiation it was 58.7%, and this difference between the methods was not significant, either. CONCLUSION: CT with low-dose radiation presented detection rates similar to those of CT with standard-dose radiation, regardless of the bones evaluated. REGISTRATION NUMBER: CRD42019148491 at the PROSPERO database.

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PURPOSE: Abnormally invasive placenta is an important cause of maternal morbidity, and its primary complication is massive bleeding. Strategies for preventing bleeding include arterial endovascular occlusion. One concern with the use of intra-arterial occlusion balloons is radiation exposure to the fetus, which occurs while determining balloon position. In this study, we sought to determine the radiation absorbed dose by the fetus during intra-aortic occlusion balloon placement in patients with abnormally invasive placenta. MATERIALS AND METHODS: We estimated the fetal absorbed dose and the entrance skin dose in the vaginal fundus and lumbar skin, respectively, using thermoluminescent dosimeter crystals, during intra-aortic balloon positioning using the mobile X-ray image intensifier system (C-arm) in digital radiography mode, directly in surgery room, without transfer to angiographic suite. We also performed a mannequin-based simulation to validate the entrance skin dose measurement technique. RESULTS: Ten women undergoing surgical management of an abnormally invasive placenta, in whom the location of the intra-aortic occlusion balloon was verified using plain radiography with C-arm in the surgery room, were included in the study. Following maternal and fetal radiation exposure, the entrance skin dose and radiation absorbed dose by the fetus were 1.31 ± 0.96 mGy and 0.27 ± 0.28 mGy, respectively, with radiation exposure durations of <1 s. CONCLUSIONS: There were no complications with the use of REBOA, the radiation absorbed dose by the fetus, entrance skin dose, and duration of radiation exposure during intra-aortic occlusion balloon placement were lower than those reported for other vascular occlusion techniques, being this a safe procedure.

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ABSTRACT Purpose This hybrid retrospective and prospective study performed on 200 consecutive patients undergoing renal CTA, investigates the opacification of renal vasculature, radiation dose, and reader confidence. Materials and Methods 100 patients were assigned retrospectively to protocol A and the other 100 were allocated prospectively to protocol B. Both protocols implemented a contrast material and saline flow rate of 4.5 mL/sec. Protocol A utilized a 100 mL of low-osmolar nonionic IV contrast material (Ioversol 350 mg I/mL) while protocol B employed a patient-tailored contrast media formula using iso-osmolar non-ionic (Iodixanol 320 mg I/mL). Results Arterial opacification in the abdominal aorta and in the bilateral main proximal renal arteries demonstrated no statistical significance (p>0.05). Only the main distal renal artery of the left kidney in protocol B was statistically significant (p<0.046). In the venous circulation, the IVC demonstrated a significant reduction in opacification in protocol B (59.39 HU ± 19.39) compared to A (87.74 HU ± 34.06) (p<0.001). Mean CNR for protocol A (22.68 HU ± 13.72) was significantly higher than that of protocol B (14.75 HU ± 5.76 p< 0.0001). Effective dose was significantly reduced in protocol B (2.46 ± 0.74 mSv) compared to A (3.07 ± 0.68 mSv) (p<0.001). Mean contrast media volume was reduced in protocol B (44.56 ± 14.32 mL) with lower iodine concentration. ROC analysis demonstrated significantly higher area under the ROC curve for protocol B (p< 0.0001), with inter-reader agreement increasing from moderate to excellent in renal arterial visualization. Conclusion Employing a patient-tailored contrast media injection protocol shows a significant refinement in the visualization of renal vasculature and reader confidence during renal CTA.

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PURPOSE: This hybrid retrospective and prospective study performed on 200 consecutive patients undergoing renal CTA, investigates the opacification of renal vasculature, radiation dose, and reader confidence. MATERIALS AND METHODS: 100 patients were assigned retrospectively to protocol A and the other 100 were allocated prospectively to protocol B. Both protocols implemented a contrast material and saline flow rate of 4.5 mL/sec. Protocol A utilized a 100 mL of low-osmolar nonionic IV contrast material (Ioversol 350 mg I/mL) while protocol B employed a patient-tailored contrast media formula using iso-osmolar non-ionic (Iodixanol 320 mg I/mL). RESULTS: Arterial opacification in the abdominal aorta and in the bilateral main proximal renal arteries demonstrated no statistical significance (p>0.05). Only the main distal renal artery of the left kidney in protocol B was statistically significant (p<0.046). In the venous circulation, the IVC demonstrated a significant reduction in opacification in protocol B (59.39 HU ± 19.39) compared to A (87.74 HU ± 34.06) (p<0.001). Mean CNR for protocol A (22.68 HU ± 13.72) was significantly higher than that of protocol B (14.75 HU ± 5.76 p<0.0001). Effective dose was significantly reduced in protocol B (2.46 ± 0.74 mSv) compared to A (3.07 ± 0.68 mSv) (p<0.001). Mean contrast media volume was reduced in protocol B (44.56 ± 14.32 mL) with lower iodine concentration. ROC analysis demonstrated significantly higher area under the ROC curve for protocol B (p<0.0001), with inter-reader agreement increasing from moderate to excellent in renal arterial visualization. CONCLUSION: Employing a patient-tailored contrast media injection protocol shows a significant refinement in the visualization of renal vasculature and reader confidence during renal CTA.

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Se sabe que las exposiciones médicas con radiaciones ionizantes son actualmente la principal fuente de exposición a la radiación artificial a nivel global. Para prevenir dosis innecesariamente altas durante estas exposiciones a los pacientes, la Comisión Internacional de Protección Radiológica (ICRP) recomienda la utilización de los Niveles de Referencia para Diagnóstico (DRLs), como una herramienta efectiva de ayuda a la optimización de la protección radiológica en la exposición médica de pacientes para diagnóstico y procedimientos de intervención. Dado que la legislación chilena no tiene incorporado aún su uso, el presente trabajo de revisión tiene como objetivo, elaborar un documento guía para los profesionales de la salud y áreas afines, que contenga de manera sucinta y con recomendaciones prácticas, los principales aspectos a tener en cuenta para establecer los DRLs en procedimientos de radiodiagnóstico, intervencionismo y medicina nuclear, basados esencialmente en la publicación N° 135 de la ICRP sobre DRLs.

It is known that medical exposition with ionizing radiation is currently the main exposition source to artificial radiation at global level. To prevent unnecessarily high doses during these patient expositions, the International Commission on Radiological Protection (ICRP) recommends the use of Diagnostic Reference Levels (DRLs), as an effective tool to support the optimization of radiological protection for patient medical exposure for diagnosis and interventional procedures. Since that the Chilean legislation does not have its use incorporated yet, the present revision work aims to elaborate a guiding document for health professionals and related fields, that succinctly and with practical recommendations, the main aspects to consider for establishing DRLs in procedures for radiodiagnostic, intervention, and nuclear medicine, mainly based in N° 135 ICRP publication about DRLs.

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OBJECTIVE: To evaluate the radiation dose received by staff in spine surgeries, including those who are not considered occupationally exposed workers. METHODS: All spinal surgeries performed in the same department during a period of 12 months were evaluated with regard to the exposure of surgeons, scrub nurses, and auxiliary personnel working in the operating room to radiation from C-arm fluoroscopy. Radiation was measured by 15 film badge dosimeters placed on the professionals' lapels, gloves, and room standardized sites. The films were analyzed in the dosimetry laboratory by collections per period. RESULTS: During the 12 months, 81 spinal surgeries were performed by the same team, with surgical times ranging from 1 to 6 hours. The total radiation dose ranged from 0.16 mSv to 2.29 mSv depending on the dosimetry site. The most exposed site was the wrist of the main surgeon. CONCLUSION: The results showed that in the spinal surgeries in our setting, the radiation doses are low and within legal limits. Nevertheless, constant training of professionals is essential for radiation protection of medical staff and patients. Level of evidence I/b, exploratory cohort study.

OBJETIVO: Avaliar a dose de radiação recebida pela equipe cirúrgica em cirurgias de coluna, incluindo entre aqueles que não são considerados trabalhadores com exposição ocupacional. MÉTODO: Todas as cirurgias de coluna realizadas num mesmo departamento num período de 12 meses foram avaliadas quanto à exposição dos cirurgiões, enfermeiros/instrumentadores e auxiliares trabalhando na sala cirúrgica à radiação do fluoroscópio tipo "C-arm". A radiação foi medida por 15 dosímetros de filme posicionados nas lapelas, luvas dos profissionais e também em pontos padronizados da sala. Os filmes foram analisados no laboratório de dosimetria em coleções por período. RESULTADOS: Durante 12 meses, 81 cirurgias de coluna foram realizadas pela mesma equipe, e cada cirurgia durou entre 1 e 6 horas. A dose total de radiação variou de 0,16 mSv a 2,29 mSv dependendo do local de mensuração. O local com maior exposição foi o punho do cirurgião principal. CONCLUSÃO: Os resultados mostraram que nas cirurgias de coluna no nosso serviço, as doses de radiação foram baixas e dentro dos limites legais. Porém, o treinamento dos profissionais é essencial para a proteção contra a radiação dos profissionais de saúde e seus pacientes. Nível de evidência I/b, estudo de coorte exploratório.

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ABSTRACT Objective: To evaluate the radiation dose received by staff in spine surgeries, including those who are not considered occupationally exposed workers. Methods: All spinal surgeries performed in the same department during a period of 12 months were evaluated with regard to the exposure of surgeons, scrub nurses, and auxiliary personnel working in the operating room to radiation from C-arm fluoroscopy. Radiation was measured by 15 film badge dosimeters placed on the professionals' lapels, gloves, and room standardized sites. The films were analyzed in the dosimetry laboratory by collections per period. Results: During the 12 months, 81 spinal surgeries were performed by the same team, with surgical times ranging from 1 to 6 hours. The total radiation dose ranged from 0.16 mSv to 2.29 mSv depending on the dosimetry site. The most exposed site was the wrist of the main surgeon. Conclusion: The results showed that in the spinal surgeries in our setting, the radiation doses are low and within legal limits. Nevertheless, constant training of professionals is essential for radiation protection of medical staff and patients. Level of evidence I/b, exploratory cohort study.

RESUMO Objetivo: Avaliar a dose de radiação recebida pela equipe cirúrgica em cirurgias de coluna, incluindo entre aqueles que não são considerados trabalhadores com exposição ocupacional. Método: Todas as cirurgias de coluna realizadas num mesmo departamento num período de 12 meses foram avaliadas quanto à exposição dos cirurgiões, enfermeiros/instrumentadores e auxiliares trabalhando na sala cirúrgica à radiação do fluoroscópio tipo "C-arm". A radiação foi medida por 15 dosímetros de filme posicionados nas lapelas, luvas dos profissionais e também em pontos padronizados da sala. Os filmes foram analisados no laboratório de dosimetria em coleções por período. Resultados: Durante 12 meses, 81 cirurgias de coluna foram realizadas pela mesma equipe, e cada cirurgia durou entre 1 e 6 horas. A dose total de radiação variou de 0,16 mSv a 2,29 mSv dependendo do local de mensuração. O local com maior exposição foi o punho do cirurgião principal. Conclusão: Os resultados mostraram que nas cirurgias de coluna no nosso serviço, as doses de radiação foram baixas e dentro dos limites legais. Porém, o treinamento dos profissionais é essencial para a proteção contra a radiação dos profissionais de saúde e seus pacientes. Nível de evidência I/b, estudo de coorte exploratório.

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INTRODUCTION: Due to potential impact of the effects of ionizing radiation used in medical and dental examinations on public health in recent years, many studies are being conducted to quantify the radiation dose values, evaluate scanners, and indicate factors that could influence or reduce radiation doses. OBJECTIVES: This study aimed to evaluate, by a systematic review, the factors that influence the effective radiation dose associated with cone beam computed tomography and respective effects, and compared the effective dose of different cone beam computed tomography (CBCT) scanners with similar exposure parameters. MATERIALS AND METHODS: A search was conducted on five databases from 2007 to 2015. RESULTS: The search identified 741 abstracts, among which 44 eligible articles were retrieved in full text. Twenty-three studies met the inclusion criteria and were included. Additional copper filter was evaluated in one study, patient size in 2 studies, region of interest in 1 study, use of a thyroid shield in 2 studies, scan angle in 3 studies, exposure time in 10 studies, FOV diameter in 17 studies, FOV height in 17 studies, kV in 16 studies, mA in 18 studies, mAs in 13 studies, voxel in 8 studies, and resolution in 3 studies. When similar exposure parameters were evaluated, it was observed that CBCT scanner with lower effective dose was Kodak® 9000C 3D (mean 21.2 µSv) in selected studies. CONCLUSIONS: Thirteen factors were related to changes in the effective dose emitted by different scanners. More studies are needed to identify the image quality requirements in addition to measure the radiation. CLINICAL RELEVANCE: Studies that give more information for professionals who request and interpret the exams and for technicians who perform 3D images about effective radiation dose associated with CBCT are necessary.

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Objetivo: avaliar caninos inclusos em tomografias computadorizadas multidetectores (TCMD) realizadas no Hospital Universitário de Santa Maria. Materiais e mé¬todo: foi realizado um estudo observacional transversal com imagens de um banco de dados de TCMD de baixa dose de radiação, solicitadas por indicações clínicas odontológicas. Os exames em formato digital imaging and communications in medicine foram avaliados por um examinador treinado, no software Weasis Medical Viewer. A avaliação dos exames compreendeu a observação das seguintes características: impactação do canino (uni ou bilateral), localização do canino (maxila ou mandíbula), localização da coroa do canino (vesti¬bular ou lingual/palatal), eixo de erupção, espessura do folículo pericoronário, presença de lesões associadas, presença de reabsorção nos dentes adjacentes e presença de agenesias dentárias ou de supranumerários. Os resultados foram avaliados de maneira descritiva, por meio de prevalência dos achados. Resultados: foram encontrados 21 caninos inclusos em 837 tomografias avaliadas (1,9%). Foi observado um predomínio de indivíduos do sexo feminino (71,4%), e a retenção do canino foi mais frequente na maxila (71,4%) e com impactação unilateral (61,9%). Quatro caninos apre¬sentaram folículo pericoronário, com espessura maior que 2 mm; 19% dos exames apresentaram reabsorção radicular externa em algum incisivo lateral. Apenas um canino apresentava lesão associada, sugerindo esclero-se óssea. Além dos caninos inclusos, foi possível avaliar alterações relacionadas às demais regiões e estruturas dentomaxilofaciais. Conclusão: apesar da amostra limitada de imagens, o presente estudo demonstrou a aplicabilidade clínica da TCMD com protocolo de baixa dose de radiação, para a avaliação dos caninos inclusos e características relacionadas a esses dentes, bem como de dentes e regiões adjacentes. (AU)

Objective: to evaluate impacted canines by tomographic exams performed at the University Hospital of Santa Maria. Materials and method: a cross-sectional observational study was performed with selected images from a database of low dose computed tomography (CT) scans requested by several dental indications. The DICOM files were evaluated by a trained examiner, using Weasis Medical Viewer software. The evaluation of each exam included the following characteristics: canine impaction (uni or bilateral), location of the canine (maxilla or mandible), location of the canine crown (buccal or lingual / palatal), shaft of canine eruption, thickness of the pericoronal follicle, presence of associated lesions, presence of external root resorption in adjacent teeth and presence of dental agenesis or supernumerary tooth. The results were evaluated in a descriptive way, through prevalence of the findings. Results: a total of 21 impacted canines were found in 837 CT scans evaluated (1,9%). A predominance of female patients was observed (71,4%); canine impaction was more frequent in the maxilla (71,4%), and unilateral (61,9%). In 19% of the exams, external root resorption occurred in some lateral incisor. Four dental elements presented pericoronal follicles thicker than 2 mm. In the evaluated sample, only one canine presented an associated lesion, suggesting bone sclerosis. Beyond the canine-related, other dental and maxillofacial changes were also evaluated. Conclusion: in spite of the limited sample, the present study demonstrated the clinical applicability of low dose CT for the evaluation of impacted canines, and characteristics related to these teeth, as well as to the adjacent teeth and regions. (AU)

Assuntos

RESUMO

OBJECTIVES: To compare reconstructed area and surface roughness of 3D models acquired using nine image acquisition protocols. Radiation dose was also compared among acquisition protocols. METHODS: A dry craniofacial specimen was scanned using three CT devices (a cone beam CT, a 16-channel fan beam CT, and a 64-channel fan beam CT), with three different acquisition protocols each. Nine 3D models were manufactured using polylactic acid. Surface roughness and reconstructed area were determined for each 3D model. The radiation dose during acquisitions was measured using lithium crystals. ANOVA was used to compare the data among the 3D models. Linear function optimization techniques based on stochastic variables were applied to identify the most suitable protocol for use. RESULTS: For surface roughness, statistically significant differences were observed among all 3D models and the specimen. For reconstructed area, CBCT and one CT-16 channel protocols originated 3D models statistically significant different from the specimen. Higher radiation doses were observed with fan beam CT acquisitions. CONCLUSIONS: All three CT devices were suitable for 3D printing when used at full resolution. The highest reconstruct area vs. radiation dose ratio was found for 64-channel CT devices.

RESUMO

AIMS: To compare the dosage of radiation the thyroid and gonad glands receive in pediatric patients undergoing chest X-rays, in distinct positions, towards the goal of developing of an X-ray tube positioning protocol. METHODS: A randomized controlled clinical trial was carried out in the Pediatric Intensive Care Unit (PICU) at the Institute of Cardiology/University Foundation of Cardiology of Rio Grande do Sul, Brazil from June 2014 to September 2016. Patients were divided into two groups. One group was positioned with the thyroid gland facing the anode end of an X-ray tube, and in the other group the thyroid gland faced the cathode end. Radiographs were evaluated by five observers, following criteria recommended by the Commission of the European Communities (CEC). RESULTS: Forty-eight pediatric patients, with a mean age of 2.0 ±â€¯1.3 years, participated in this study. Based on the evaluation of 48 images, it was determined that the thyroid and gonad glands facing the cathode were exposed to 13.3 ±â€¯3.1 µGy and 13.5 ±â€¯4.1 µGy of radiation, respectively (p = 0.008). Additionally, the thyroid and gonad glands facing the anode were exposed to 11.7 ±â€¯3.1 µGy and 12.7 ±â€¯3.1 µGy of radiation, respectively (p = 0.007). The mean input dose in the center of the chest was 20.8 ±â€¯9.6 µGy in both positions. DISCUSSION: The proximity of the thyroid gland to the cathode end of the X-ray tube appears to be related to the dosage of ionizing radiation. Adverse effects associated with exposure to ionizing radiation could be minimized by positioning the thyroid gland to the anodic end of the X-ray tube. CONCLUSION: Patients should be placed facing the anode end of the X-ray tube when taking thoracic X-rays, in order to reduce radiation exposure to the thyroid and gonad glands.ClinicalTrials.gov Identifier: NCT02925936.

RESUMO

PURPOSE: To analyze cone-beam computed tomography (CBCT) use, indications, and exposure parameters in San José, Costa Rica. MATERIALS AND METHODS: A cross-sectional study was performed. All CBCT examinations over a period of 6 months at 2 radiological centers in San José, Costa Rica were evaluated. The examinations were performed with Veraview EPOC X550 and Veraviewepocs 3D R100 equipment. The patients' age and sex, clinical indication for CBCT, region of interest (ROI), repeat examinations, specialty of the referring dentist, field-of-view (FOV), tube voltage (kV), tube current (mA), and radiation dose (µGy) were evaluated. Patients were classified by age as children (≤12 years), adolescents (13-18 years), and adults (≥19 years). RESULTS: The mean age of the 526 patients was 49.4 years. The main indications were implant dentistry and dental trauma. The most frequent ROIs were posterior, while anterior ROIs were much less common. The highest percentage of repeat examinations was in children. Fifty-six percent of the referring dentists were specialists. The most commonly used FOV was small. The mean tube voltage and current were 79.8 kV and 7.4 mA for Veraview EPOC X550 and 89.9 kV and 6 mA for Veraviewepocs 3D R100, respectively. The mean doses for children, adolescents, and adults were 6.9 µGy, 8.4 µGy, and 7.8 µGy, respectively. CONCLUSION: Although CBCT was most commonly used in adults for implant dentistry, most repeat examinations were in children, and the highest mean dose was in adolescents. Additional dose optimization efforts should be made by introducing low-dose protocols for children and adolescents.