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1.
Arq. bras. cardiol ; 116(1): 100-105, Jan. 2021. tab
Article in English, Portuguese | LILACS | ID: biblio-1152972

ABSTRACT

Resumo Fundamento Qualidade de imagem e dose de radiação são otimizadas com uma frequência cardíaca (FC) lenta e estável na realização de imagens de artérias coronárias durante a angiografia cardíaca por tomografia computadorizada (CCTA, do inglês cardiac computed tomography angiography) A segurança, a eficácia e o protocolo para a redução da FC com medicamento betabloqueador ainda não foi bem descrita em uma população de pacientes pediátricos. Objetivo Oferecer um protocolo de dose de metoprolol eficiente a ser usado em pacientes pediátricos externos durante a CCTA. Métodos Realizamos uma revisão retrospectiva de todos os pacientes pediátricos externos que receberam o metoprolol durante a CCTA. As características demográficas e clínicas foram resumidas e a redução média em FC foi estimada utilizando-se um modelo de regressão linear multivariada. As imagens foram avaliadas em uma escala de 1 a 4 (1= ideal). Resultados Um total de 78 pacientes externos passaram a uma CCTA com o uso de metoprolol. A média de idade foi de 13 anos, a média de peso foi de 46 kg, e 36 pacientes (46%) eram do sexo masculino. As doses médias de metoprolol foram 1,5 (IQR 1,1; 1,8) mg/kg, e 0,4 (IQR 0,2; 0,7) mg/kg para administrações orais e intravenosas, respectivamente. O produto dose-comprimento por exame foi de 57 (IQR 30, 119) mGy*cm. A redução média da FC foi 19 (IQR 12, 26) batimentos por minuto, ou 23%. Não foram relatadas complicações ou eventos adversos. Conclusão O uso de metoprolol num cenário de pacientes pediátricos externos para redução da FC antes de uma CCTA é seguro e eficiente. Pode-se reproduzir um protocolo de dose de metoprolol quando for necessário atingir uma FC mais lenta, garantindo tempos de aquisição mais rápidos, imagens mais claras e redução na exposição à radiação nessa população. (Arq Bras Cardiol. 2021; 116(1):100-105)


Abstract Background Image quality and radiation dose are optimized with a slow, steady heart rate (HR) when imaging the coronary arteries during cardiac computed tomography angiography (CCTA). The safety, efficacy, and protocol for HR reduction with beta blocker medication is not well described in a pediatric patient population. Objective Provide a safe and efficient metoprolol dose protocol to be used in pediatric outpatients undergoing CCTA. Methods We conducted a retrospective review of all pediatric outpatients who received metoprolol during CCTA. Demographic and clinical characteristics were summarized and the average reduction in HR was estimated using a multivariate linear regression model. Images were evaluated on a 1-4 scale (1= optimal). Results Seventy-eight pediatric outpatients underwent a CCTA scan with the use of metoprolol. The median age was 13 years, median weight of 46 kg, and 36 (46%) were male. The median doses of metoprolol were 1.5 (IQR 1.1, 1.8) mg/kg and 0.4 (IQR 0.2, 0.7) mg/kg for oral and intravenous administrations, respectively. Procedural dose-length product was 57 (IQR 30, 119) mGy*cm. The average reduction in HR was 19 (IQR 12, 26) beats per minute, or 23%. No complications or adverse events were reported. Conclusion Use of metoprolol in a pediatric outpatient setting for HR reduction prior to CCTA is safe and effective. A metoprolol dose protocol can be reproduced when a slower HR is needed, ensuring faster acquisition times, clear images, and associated reduction in radiation exposure in this population. (Arq Bras Cardiol. 2021; 116(1):100-105)


Subject(s)
Humans , Male , Child , Adolescent , Coronary Artery Disease , Metoprolol/adverse effects , Outpatients , Radiation Dosage , Retrospective Studies , Coronary Angiography , Computed Tomography Angiography , Heart Rate
2.
Rev. Fac. Odontol. (B.Aires) ; 36(82): 49-55, 2021. ilus, tab
Article in Spanish | LILACS | ID: biblio-1291932

ABSTRACT

Objetivos: Mensurar los niveles de radiación de fuga y dispersión emanada a través de los blindajes y estructuras plomadas del tubo de rayos X de la unidad dental portátil NOMAD, controlando la retrodispersión con el uso del escudo protector de acrílico plomado adaptado en el extremo final del tubo localizador plomado. Se midieron las tasas de exposición dispersadas mediante un detector tipo Geiger-Müller y una cámara de ionización con respuesta en el rango de energías aportadas en diagnóstico por imágenes para la medición de la exposición directa y determinación posterior de las dosis. Se utilizó un fantomas diseñado para diagnóstico odontológico, sopesando la radiación en diferentes angulaciones de operación del equipo NOMAD, simulando los gestos posturales de odontólogos, radiólogos y sujetos a identificar. Se controlaron las tasas de exposición para determinar los valores de las dosis aportadas en las zonas significativas corporales más radiosensibles del operador del equipo. Se obtuvo como resultado que la retrodispersión en el cristalino del ojo del operador fue significativamente menor cuando el fantomas estaba acostado, mientras que a nivel de gónadas resultó más baja con el cuerpo sentado. La tasa de dosis máxima de radiación dispersa que impactó en los operadores fue de 350.8 micro Sieverts por hora (uSv/h) en la zona de gónadas, por cada radiografía tomada sin el uso del delantal de goma plomada, reduciéndose a 4.38 micro Sieverts por hora (uSv/h) al utilizarlo (AU)


Subject(s)
Humans , Male , Female , Radiography, Dental/methods , Technology, Dental , Dental Equipment , Forensic Dentistry , Patients , Argentina , Radiation Dosage , Radiation Protection , Scattering, Radiation , Diagnostic Imaging/methods , Victims Identification , Radiation Exposure Control , Equipment Design
3.
Article in Chinese | WPRIM | ID: wpr-887876

ABSTRACT

Objective To design a novel automatic dispensing and injecting system of positron radiopharmaceuticals,for precise dose dispensing,simplified operation,and reduction of occupational radiation exposure. Methods The automatic dispensing and injecting system was fabricated with tungsten alloy as the shielding material.The performance and radiation protection of the device were assessed. Results The total time of injection using the automatic dispensing and injecting system was about 60 s.The ratio of successful injection in stability test was 100%.The deviation of the dispensing dose with the system was ≤3%.With the tungsten alloy shield(40 mmPb of the cabinet,60 mmPb of the countertop,15 mmPb of the protective shield,and 50 mmPb of the inbuilt jar for radiopharmaceuticals),the average dose rate at 30 cm from the device was 1.44 μSv/h,and the radiation dose at the operator's extremity was reduced by 99%. Conclusions This automatic dispensing and injecting system of positron radiopharmaceuticals is easy to operate with precise dispensing dose.It is safe and meets the requirements of radiation protection.


Subject(s)
Electrons , Occupational Exposure/analysis , Radiation Dosage , Radiation Protection , Radiopharmaceuticals
4.
Article in English | WPRIM | ID: wpr-887726

ABSTRACT

Objective@#To obtain precise data on the changes in the levels of 29 cytokines in mice after high or low linear energy transfer (LET) irradiation and to develop an accurate model of radiation exposure based on the cytokine levels after irradiation.@*Methods@#Plasma samples harvested from mice at different time points after carbon-ion or X-ray irradiation were analyzed using meso-scale discovery (MSD), a high-throughput and sensitive electrochemiluminescence measurement technique. Dose estimation equations were set up using multiple linear regression analysis.@*Results@#The relative levels of IL-6 at 1 h, IL-5 and IL-6 at 24 h, and IL-5, IL-6 and IL-15 at 7 d after irradiation with two intensities increased dose-dependently. The minimum measured levels of IL-5, IL-6 and IL-15 were up to 4.0076 pg/mL, 16.4538 pg/mL and 0.4150 pg/mL, respectively. In addition, dose estimation models were established and verified.@*Conclusions@#The MSD assay can provide more accurate data regarding the changes in the levels of the cytokines IL-5, IL-6 and IL-15. These cytokines could meet the essential criteria for radiosensitive biomarkers and can be used as radiation indicators. Our prediction models can conveniently and accurately estimate the exposure dose in irradiated organism.


Subject(s)
Animals , Biological Assay , Biomarkers/blood , Carbon , Cytokines/blood , Female , Heavy Ions , Linear Energy Transfer , Linear Models , Mice , Radiation Dosage , Radiation, Ionizing
5.
Article in English | WPRIM | ID: wpr-880333

ABSTRACT

BACKGROUND@#Numerous studies have concentrated on high-dose radiation exposed accidentally or through therapy, and few involve low-dose occupational exposure, to investigate the correlation between low-dose ionizing radiation and changing hematological parameters among medical workers.@*METHODS@#Using a prospective cohort study design, we collected health examination reports and personal dose monitoring data from medical workers and used Poisson regression and restricted cubic spline models to assess the correlation between changing hematological parameters and cumulative radiation dose and determine the dose-response relationship.@*RESULTS@#We observed that changing platelet of 1265 medical workers followed up was statistically different among the cumulative dose groups (P = 0.010). Although the linear trend tested was not statistically significant (P@*CONCLUSION@#We concluded that although the exposure dose was below the limit, medical workers exposed to low-dose ionizing radiation for a short period of time might have increased first and then decreased platelets, and there was a dose-response relationship between the cumulative radiation dose and platelets changing.


Subject(s)
Adult , Aged , Blood Platelets/radiation effects , Female , Health Personnel/statistics & numerical data , Humans , Male , Middle Aged , Occupational Exposure/adverse effects , Prospective Studies , Radiation Dosage , Radiation Exposure/adverse effects , Radiation, Ionizing , Young Adult
6.
Int. j. odontostomatol. (Print) ; 14(4): 610-616, dic. 2020. tab
Article in Spanish | LILACS | ID: biblio-1134547

ABSTRACT

RESUMEN: Las exposiciones médicas con radiación ionizante son actualmente la principal fuente de exposición a la radiación artificial a nivel global, entre ellas, los exámenes dentales corresponden a uno de los más frecuentes. Para prevenir dosis innecesariamente altas a los pacientes durante estas exposiciones, la Comisión Internacional de Protección Radiológica (ICRP) recomienda la utilización de 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. Dado que la legislación de Chile aún no ha incorporado el uso de los DRLs, el presente trabajo de revisión tuvo como objetivo analizar la publicación N° 135 de la ICRP para generar un documento que sirva de guía para los odontólogos, explicando de manera didáctica y en un lenguaje sencillo, pero técnico, los principales aspectos a tener en cuenta para establecer los DRLs en procedimientos de radiología dental.


SUMMARY: Currently exposure to ionizing radiation is currently the main source of exposure to artificial radiation worldwide, with dental examinations being one of the most frequent events. In order to prevent exposure of unnecessarily high doses in patients, the International Commission on Radiological Protection (ICRP) recommends the use of Diagnostic Reference Levels (DRLs), as an effective tool to help maximize protection from radiation during medical exposure of patients. Given that the Chilean legislation has not yet incorporated the use of DRLs, the purpose of this study was to analyze publication N° 135 of the ICRP to generate a document, to serve as a guide for dentists, didactically outlining in simple but technical language, the main aspects to consider when establishing DRLs in dental radiology procedures.


Subject(s)
Humans , Radiation Protection/standards , Radiography, Dental/methods , Radiation Dosage , Radiation Protection/methods , International Agencies , Practice Guideline , Radiation Exposure/prevention & control , Evaluation Studies as Topic
7.
Arq. bras. cardiol ; 115(6): 1154-1161, dez. 2020. tab, graf
Article in English, Portuguese | LILACS | ID: biblio-1152938

ABSTRACT

Resumo Fundamento Nos últimos anos, o recente aumento no número de procedimentos intervencionistas tem resultado em crescente preocupação em relação à exposição radiológica por pacientes e equipe médica. A avaliação da exposição dos níveis de radiação em crianças é difícil devido à grande variabilidade no peso corporal. Portanto, os valores de referência de radiação não estão bem definidos para essa população. Objetivos Avaliar e validar a razão do produto dose-área (DAP) em relação ao peso corporal como uma medida de referência de radiação em cateterismos cardíacos em crianças. Métodos Estudo multicêntrico observacional com dados do Registro Brasileiro de Cateterismo Cardíaco em Cardiopatias Congênitas (CHAIN) de março de 2013 a junho de 2014. Os critérios de inclusão foram: pacientes <18 anos submetidos a procedimentos hemodinâmicos para cardiopatia congênita, com DAP devidamente registrado. Foram considerados diferenças estatísticas significativas os valores de p < 0,05. Resultados Este estudo avaliou 429 pacientes com idade e peso medianos de 50 (10, 103) meses e 15 (7, 28) kg, respectivamente. O DAP mediano foi de 742,2 (288,8, 1.791,5) μGy.m2. Houve uma boa correlação entre o DAP e o produto peso/tempo de fluoroscopia (rs=0,66). Não foi observada diferença estatisticamente significativa na relação DAP/peso entre procedimentos terapêuticos e diagnósticos. Houve ampla variação da relação DAP/peso entre os procedimentos terapêuticos (p<0.001). Conclusões A proporção DAP/peso é a medida mais simples e aplicável para avaliar a exposição radiológica em uma população pediátrica. Apesar da escassa literatura disponível, as doses obtidas no presente estudo foram semelhantes àquelas encontradas anteriormente. Estudos de validação e comparação são importantes na avaliação do impacto de estratégias para redução da exposição radiológica nessa população. (Arq Bras Cardiol. 2020; [online].ahead print, PP.0-0)


Abstract Background In recent years the increasing number of interventional procedures has resulted in growing concerns regarding radiation exposure for patients and staff. The evaluation of radiation exposure in children is difficult due to the great variability in body weight. Therefore, reference levels of radiation are not well defined for this population. Objectives To study and validate the ratio of dose-area product (DAP) to patient weight as a reference measurement of radiation for hemodynamic congenital heart disease procedures in children. Methods This observational multicenter study uses data obtained from a Brazilian registry of cardiac catheterization for congenital heart disease from March 2013 to June 2014. Inclusion criteria were all patients aged <18 years old undergoing hemodynamic procedures for congenital heart disease, with recorded DAP doses. P-value < 0.05 was considered as statistically significant. Results This study evaluated 429 patients with median age and weight of 50 (10, 103) months and 15 (7, 28) kg, respectively. Median DAP was 742.2 (288.8, 1,791.5) μGy.m2. There was a good correlation between DAP and weight-fluoroscopic time product(rs=0.66). No statistically significant difference was observed in DAP/weight ratio between therapeutic and diagnostic procedures. There was a wide variation in the DAP/weight ratio among the therapeutic procedures (p<0.001). Conclusions The DAP/weight ratio is the simplest and most applicable measurement to evaluate radiation exposure in a pediatric population. Although there is limited literature available, the doses obtained in the present study were similar to those previously found. Ongoing research is important to evaluate the impact of strategies to reduce radiation exposure in this population (Arq Bras Cardiol. 2020; [online].ahead print, PP.0-0)


Subject(s)
Humans , Child, Preschool , Child , Adolescent , Aged , Radiation Exposure/adverse effects , Heart Defects, Congenital , Radiation Dosage , Brazil , Fluoroscopy , Cardiac Catheterization/adverse effects , Radiography, Interventional , Registries
8.
Rev. chil. cardiol ; 39(2): 105-113, ago. 2020. tab, graf
Article in Spanish | LILACS | ID: biblio-1138523

ABSTRACT

ANTECEDENTES: Las unidades de Cardiología intervencional han evidenciado un número creciente de procedimientos, cada vez más variados y complejos, lo cual podría eventualmente generar daños a los profesionales ocupacionalmente expuestos a radiaciones ionizantes (POEs) de no contar con los adecuados elementos de radioprotección y un uso correcto de ellos. OBJETIVO: Caracterizar la disponibilidad y utilización de los elementos de radioprotección y dosimetría de unidades de cardiología intervencionista de centros Sudamericanos. MATERIAL Y MÉTODOS: Se realizó una encuesta autoaplicada a 139 POEs, de ambos sexos de 7 países, a través de una plataforma on-line, se les consultó sobre características demográficas, dosimétricas y de radioprotección. RESULTADOS: Los elementos de radioprotección más tradicionales; delantales y cuellos plomados se utilizaron un 99,5 % y 98,4 % respectivamente, aquellos elementos más recientes como gafas, gorros y paños plomados solo alcanzaron un 36,8 %, 6,8 % y 34,2%, de utilización respectivamente, en cuanto a la utilización de los dosímetros, solo un 7,9 % lo hace apegado a las normas de la Organización Internacional de Energía Atómica (OIEA). CONCLUSIÓN: Se constató en la muestra analizada una falta de elementos de radioprotección y un uso inadecuado de ellos, urge realizar intervenciones educativas y técnicas para mejorar estos datos.


BACKGROUND: Due to the increasing number of interventional cardiology procedures currently performed, health professionals (POE) are exposed to ionizing radiation unless adequate protective elements are used. AIM: to describe the use of radioprotection elements and dosimetry in interventional cardiology laboratories in South America. METHODS: A self-administered survey was performed on 139 POE of both sexes and 7 countries using an online platform. Demographic data, dosimetry and characteristics of radioprotection analyzed. RESULTS: Commonly used radioprotective elements (lead aprons and collars) were used in 99.5% and 98% respectively. Recently introduced protection elements like lead goggles, caps and drapery were used in 36.8, 6.8 and 34.2% , respectively. Dosimetry according to the International Atomic Energy Commission (OIAE) was performed in only 7.9% of the procedures. CONCLUSION: there is a severe lack of adequate radioprotection during interventional cardiology procedures. Urgent measures, including technical implementation and educational interventions are needed to improve radioprotection in interventional cardiology.


Subject(s)
Humans , Male , Female , Adult , Radiation Protection/methods , Radiography, Interventional/adverse effects , Occupational Exposure/prevention & control , Cardiology Service, Hospital , Radiation Dosage , Radiation, Ionizing , Radiation Protection/instrumentation , Radiation Protection/statistics & numerical data , South America , Pilot Projects , Surveys and Questionnaires , Self Report , Personal Protective Equipment
9.
Rev. chil. radiol ; 26(2): 40-45, jun. 2020. graf
Article in Spanish | LILACS | ID: biblio-1126192

ABSTRACT

Resumen: La protección gonadal ha sido durante largo tiempo un importante factor para abordar el requisito "tan bajo como sea razonablemente posible" ALARA. El presente artículo realiza una revisión sistemática sobre la utilidad de la protección gonadal en la radiografía de pelvis en la cual se han destacado los factores que tienen que ver con su realización diaria, es decir, la dosis de radiación involucrada, la radiosensibilidad de las gónadas, la posición del protector gonadal y el factor psicológico de la población en relación con su uso. La incorporación de equipamientos modernos, con dosis y protocolo optimizados, transforma el beneficio de la protección en un tema al menos debatible. Mientras algunos siguen respaldando la medida, otros organismos y autores ya no la respaldan. Es necesario reconsiderar prácticas actuales fundadas en consensos científicos que pueden estar obsoletos y considerar el factor de cambio cultural basados en estos nuevos consensos para su implementación, sin generar mayor preocupación en la población.


Abstract: Gonadal protection has long been an important factor in addressing the ALARA "as low as reasonably possible" requirement. This article performs a systematic review on the usefulness of gonadal protection in pelvic radiography, in which the factors that have to do with its daily performance have been highlighted, that is, radiation dose involved, the radiosensitivity of the gonads, the position of the gonadal shielding and the psychological factor of the population in relation to its use. The incorporation of modern equipment, with optimized dose and protocols, transforms the benefit of gonad shielding into an issue that is at least debatable. While some continue to support the measure, other agencies and authors no longer support it. It is necessary to reconsider current practices based on scientific consensus that may be obsolete and consider the factor of cultural change based on these new consensus for its implementation, without generating major concern in the population.


Subject(s)
Humans , Child , Pelvis/diagnostic imaging , Radiation Protection/methods , Gonads/radiation effects , Radiation Dosage , X-Rays , Radiography
10.
Rev. bras. anestesiol ; 70(3): 233-239, May-June 2020. tab, graf
Article in English, Portuguese | LILACS | ID: biblio-1137183

ABSTRACT

Abstract Background: The primary objective of this study was to investigate the effect of low dose ionizing radiation exposure on thiol/disulfide homeostasis and ischemia modified albumin levels. The secondary objective is to compare thiol/disulfide homeostasis and ischemia modified albumin levels among the personnel exposed to low dose ionizing radiation in anesthesia application areas, in and out of the operation room. Methods: The study included a total of 90 volunteers aged between 18 and 65 years old, with 45 personnel working in a setting with potential for radiation exposure (Exposed Group) and 45 personnel in a setting without radiation exposure (Control Group). Their native thiol, total thiol, disulphide, albumine and IMA levels were measured. Exposed group included personnel who were exposed to radiation outside the operating room - Operation room (−) Group and inside the operating room - Operation room (+) Group. Results: Albumin, native and total thiol levels were significantly lower in the participants exposed to radiation in the anesthesia application area; no statistically significant difference was found in terms of disulfide and ischemia modified albumin levels. In the Operation room (−) Group exposed to radiation, native thiol and total thiol values were significantly lower compared to the Operation room (+) Group. Conclusion: Awareness of being in danger of oxidative stress should be established in personnel exposed to radiation in the anesthesia application area following low dose ionizing radiation exposure, and the necessary measures should be taken.


Resumo Justificativa: O objetivo principal do estudo foi investigar o efeito de exposição à radiação ionizante de baixa dose nos níveis de homeostase tiol/dissulfeto e de albumina modificada por isquemia. O objetivo secundário foi comparar os níveis de homeostase tiol/dissulfeto e albumina modificada por isquemia entre indivíduos expostos à radiação ionizante de baixa dose nas áreas de procedimentos anestésicos, dentro e fora da sala de cirurgia. Método: O estudo incluiu um total de 90 voluntários com idades entre 18 e 65 anos, 45 profissionais que trabalhavam em ambiente de exposição potencial a radiação (Grupo Exposto) e 45 profissionais que trabalhavam em ambiente sem exposição à radiação (Grupo Controle). Foram medidos os níveis de tiol nativo, tiol total, dissulfeto, albumina e albumina modificada por isquemia. O Grupo Exposto era constituído por profissionais expostos a radiação fora da sala de cirurgia - Grupo sala de cirurgia (-) e na sala de cirurgia - Grupo sala de cirurgia (+). Resultados: Os níveis de albumina, tiol nativo e total foram significantemente mais baixos nos participantes expostos à radiação em área de realização de anestesia, e nenhuma diferença estatisticamente significante foi encontrada para os níveis de dissulfeto e albumina modificada por isquemia. No Grupo exposto sala de cirurgia (-), os valores de tiol nativo e tiol total foram significantemente mais baixos quando comparados ao Grupo sala de cirurgia (+). Conclusões: Os profissionais expostos à radiação em área de realização de anestesia devem ser conscientizados quanto ao perigo do estresse oxidativo após exposição à radiação ionizante de baixa dose e medidas cabíveis devem ser instituídas.


Subject(s)
Humans , Male , Female , Adolescent , Adult , Aged , Young Adult , Radiation Dosage , Radiation, Ionizing , Sulfhydryl Compounds/radiation effects , Sulfhydryl Compounds/blood , Occupational Exposure , Radiation Exposure , Disulfides/radiation effects , Disulfides/blood , Serum Albumin, Human/radiation effects , Homeostasis/radiation effects , Operating Rooms , Biomarkers/blood , Prospective Studies , Middle Aged
11.
Diagn. tratamento ; 25(2): 01-06, abr.-jun. 2020. graf, tab
Article in Portuguese | LILACS | ID: biblio-1115997

ABSTRACT

Contexto: A tomografia computadorizada revolucionou os estudos radiológicos convencionais. Porém, tal avanço se deu associado com o aumento das doses de radiação ionizante. A tomografia computadorizada representa 15% de todos os exames de imagem e contribui com 75% de radiação para a população. Objetivo: Estimar a dose efetiva de radiação imprimida aos pacientes durante os exames de tomografia computadorizada. Desenho e local: Estudo retrospectivo e descritivo em instituição hospitalar de nível terciário no Rio de Janeiro. Métodos: Foram selecionados 1.476 pacientes que realizaram exames de tomografia computadorizada de crânio, tórax e abdome/pelve, sem contraste endovenoso, no serviço de radiodiagnóstico do hospital no período de 1 de janeiro a 31 de março de 2018 para os exames de tórax, e no período de 1 de janeiro a 28 de fevereiro de 2018 para os exames de crânio e de abdome/pelve. Os dados foram coletados a partir do Picture Archivingand Communication System (PACS) da instituição para avaliar a dose de radiação utilizada por cada tipo de exame, por meio do cálculo das doses efetivas médias em cada tipo de exame. Resultados: As médias das doses efetivas encontradas foram de 1,57 mSv, 8,37 mSv e 12,28 mSv para os exames de crânio, tórax e abdome/pelve, respectivamente. Conclusão: O estudo verificou que os exames de crânio e abdome/pelve foram realizados com as médias das doses efetivas dentro dos valores típicos preconizados, enquanto nos exames de tórax as doses efetivas estavam acima da faixa fornecida pela Associação Americana de Física Médica (American Association of Physicists in Medicine, AAPM) (relatório # 96).


Subject(s)
Radiation Dosage , Radiation, Ionizing , Radiation Protection , Tomography, X-Ray Computed , Dosimetry
12.
Rev. chil. cardiol ; 39(1): 8-15, abr. 2020. tab, graf
Article in Spanish | LILACS | ID: biblio-1115444

ABSTRACT

ANTECEDENTES: Un número creciente de artículos está llamando la atención en forma consistente sobre la eventual asociación que existe entre los denominados trabajadores ocupacionalmente expuestos a bajos niveles de radiación ionizante (POEs) y una mayor frecuencia de aberraciones cromosómicas, a nivel Sudamericano estos estudios son escasos. OBJETIVO: Evaluar la frecuencia de aberraciones cromosómicas en linfocitos de sangre periférica de POEs de un hospital y de sujetos sanos. Adicionalmente, se realizó una revisión exhaustiva de los artículos que a la fecha abordaron este tema. MATERIAL Y MÉTODO: Se condujo un análisis citogenético destinado a cuantificar las aberraciones cromosómicas en sangre periférica de linfocitos de 6 POEs de la unidad de Cardiología Intervencional y, como controles, 6 muestras de sujetos de la población general fueron analizadas. RESULTADOS: Se observó un importante contraste en el número de aberraciones cromosómicas presentadas en los POEs versus la población general no expuesta a radiaciones ionizantes, siendo esta de una relación de 6:1, respectivamente. CONCLUSIÓN: Los resultados preliminares indican una mayor frecuencia de aberraciones cromosómicas en los POEs versus la población general, sin embargo, se deberá esperar los resultados de la segunda fase de investigación, donde al ampliar la muestra en análisis se podrán obtener conclusiones estadísticamente significativas.


BACKGROUND: There is growing evidence of an increased number of chromosomes aberrations in subjects exposed to low levels of ionizing radiation (POEs). There are few studies on this subject in Latin America AIM: To evaluate the frequency of chromosome aberrations in lymphocytes obtained from peripheral blood in subjects working in laboratories where low levels of ionizing radiation are present and to compare these findings to those of unexposed subjects. METHODS: A cytogenic analysis to quantify chromosome aberrations was performed in 6 POs subjects from a cardiology invasive laboratory and 6 controls from a general unexposed population. RESULTS: Compared to controls, an approximately 6-fold increase in the number of chromosome aberrations was observed.in subjects exposed to ionizing radiation CONCLUSION: These preliminary results indicate that there is an increased number of chromosome aberrations in subjects exposed to low levels of ionizing radiation, as occurs in people working in a cardiology interventional laboratory. Studies in large numbers of subjects and preferably followed prospectively are needed to evaluate more precisely this effect.


Subject(s)
Humans , Male , Female , Personnel, Hospital , Radiation, Ionizing , Chromosome Aberrations/radiation effects , Cardiology Service, Hospital , Radiation Dosage , Lymphocytes/radiation effects , Chile , Pilot Projects , Occupational Exposure , Chromosome Aberrations/statistics & numerical data , Chromosomes, Human/radiation effects , Cytogenetic Analysis
13.
Rev. chil. radiol ; 26(1): 25-31, mar. 2020. tab
Article in Spanish | LILACS | ID: biblio-1115522

ABSTRACT

Resumen: Debido al aumento en el uso de la Tomografía Computada (TC), y en consecuencia, la probabilidad de generar un incremento progresivo de la dosis recibida por los paciente y su relación en el potencial riesgo de los efectos de las radiaciones ionizantes, es importante implementar el uso de niveles de referencia diagnóstico (DRLs) en TC, como herramienta fundamental dentro de un programa de control de calidad que permita la evaluación y optimización de las dosis entregadas a los pacientes según la tarea clínica deseada. Con el objetivo de establecer valores típicos de dosis en TC de cerebro en Clínica Bupa Reñaca, se estudió una muestra de 73 informes dosimétricos generados en un equipo TC Toshiba Aquilion 64, en términos de indicadores de dosis para TC: Índice de dosis en TC por volumen (CTDIvol) y Producto dosis longitud (DLP). Con los datos obtenidos, se estimó el valor del percentil 50 (p50) para cada indicador de dosis, y se determinaron los valores típicos de dosis en cada grupo estudiado según sexo, edad e indicación clínica. Se logró definir y establecer una metodología que permitió la obtención de los valores típicos de dosis para TC de cerebro, optimizando las dosis sin producir una disminución en la calidad de la imagen necesaria para nuestro propósito clínico.


Abstract: Due to the increase in the use of Computed Tomography (CT), and consequently, the probability of generating a progressive increase in the dose received by the patient and its relationship in the potential risk of the effects of ionizing radiation, it is important to implement the use of diagnostic reference levels (DRLs) in CT, as a fundamental tool within a quality control program that allows the evaluation and optimization of the doses delivered to patients according to the desired clinical task. In order to establish typical dose values in brain CT at Bupa Reñaca Clinic, a sample of 73 dosimetric reports generated on a Toshiba Aquilion 64 CT unit was studied, in terms of dose indicators for CT: Dose rate on CT by volume (CTDIvol) and Dose Length Product (DLP). With the data obtained, the value of the 50th percentile (p50) for each dose indicator was estimated, and typical dose values were determined in each group studied according to sex, age and clinical indication. It was possible to define and establish a methodology that allowed obtaining typical dose values for brain CT, optimizing the doses without producing a decrease in the image quality necessary for our clinical purpose.


Subject(s)
Humans , Male , Female , Adolescent , Adult , Middle Aged , Young Adult , Radiation Dosage , Brain/diagnostic imaging , Tomography, X-Ray Computed/standards , Diagnostic Reference Levels , Quality Control , Radiation, Ionizing , Brain/radiation effects , Tomography, X-Ray Computed/methods , Cross-Sectional Studies , Process Optimization
15.
An. bras. dermatol ; 95(1): 46-51, Jan.-Feb. 2020. graf
Article in English | LILACS | ID: biblio-1088734

ABSTRACT

Abstract Background: Organoid cultures are primary cultures that maintain architectural characteristics and the relationships between cells, as well as the extracellular matrix. They are alternatives for pathophysiological or therapeutic investigation rather than animal and in vitro tests. Objective: Development of a cutaneous organoid culture model, aiming at the study of radiation-induced melanogenesis. Method: A validation study, which involved biopsies of the skin of the back of the adult ear. One sample was irradiated with different doses of UVB, UVA, or visible light (VL); the other was maintained in the dark for 72 h. The viability of the tissues was evaluated from the morphological and architectural parameters of the histology, and the expression of the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene, by real-time polymerase chain reaction (PCR). The radiation-induced melanin pigmentation was standardized according to the doses of each radiation and evaluated by digital image analysis (Fontana-Masson). Results: The primary skin culture was standardized at room temperature using DMEM medium. The doses of UVB, UVA, and VL (blue light) that induced differential melanogenesis were: 166 mJ/cm2, 1.524 J/cm2, and 40 J/cm2. The expression of the GAPHD constitutional gene did not differ between the sample of skin processed immediately after tissue collection and the sample cultured for 72 h in the standardized protocol. Study limitations: This was a preliminary study that evaluated only the viability and integrity of the melanogenic system, and the effect of the radiation alone. Conclusions: The standardized model maintained viable melanocytic function for 72 h at room temperature, allowing the investigation of melanogenesis induced by different forms of radiation.


Subject(s)
Humans , Adult , Ultraviolet Rays , Organoids/radiation effects , Cell Culture Techniques/standards , Light , Melanins/biosynthesis , Melanins/radiation effects , Radiation Dosage , Silver Nitrate , Time Factors , Biopsy , Skin Pigmentation/radiation effects , Gene Expression , Cells, Cultured , Reproducibility of Results , Real-Time Polymerase Chain Reaction
16.
Rev. colomb. radiol ; 31(2): 5328-5334, jun. 2020. imag, fig
Article in Spanish | LILACS, COLNAL | ID: biblio-1343284

ABSTRACT

Introducción: El uso de dosis adecuadas de radiación en pacientes pediátricos es un deber de los centros de diagnóstico médico debido a las características y retos que implica esta población. Por lo anterior, se han establecido unos niveles internacionales de referencia de dosis (DRL, del inglés dose reference level) para optimizar y comparar los protocolos de cada institución. En Colombia no se cuenta con estudios al respecto. Objetivo: Mostrar los DRL utilizados en un hospital universitario de alta complejidad en las modalidades de tomografía computarizada (TC), radiografía y fluoroscopia y compararlos con los estándares internacionales. Metodología: Estudio descriptivo retrospectivo realizado entre 2018 y 2019. Se analizaron datos de producto dosis longitud (DLP) para TC de cráneo, tórax, abdomen y TC de tórax de alta resolución (TACAR); y producto dosis área (DAP) para radiografía de tórax, abdomen, huesos y fluoroscopia por grupos etarios. Resultados: Se obtuvieron los datos de 780 pacientes: 360 radiografías, 100 de fluoroscopia y 320 tomografías. Se encontró que los niveles de referencia de dosis de radiación usados en el hospital son bajos, comparados con guías europeas de 2018 de niveles de referencia. Se describen DRL para cada estudio y grupo etario. Conclusión: Se demostró que en el hospital donde hizo el estudio los niveles de referencia de radiación en la población pediátrica son bajos. El presente trabajo puede servir como referente nacional.


Introduction: Due to the characteristics and challenges of the pediatric population regarding radiation, the use of adequate doses of radiation is a duty of medical diagnostic centers. For this reason, the Dose Reference Levels (DRL) have been established in many countries to optimize and monitor the protocols of each institution. In Colombia there are no studies in this subject. Objective: To show the DRLs used in a university hospital of high complexity in the modalities of computed tomography (CT), radiography and fluoroscopy and to compare them with international standards. Methodology: Retrospective descriptive trial between 2018 and 2019. We analyzed dose length product (DLP) data for skull, chest, abdomen, and high-resolution chest CT (HRCT); and dose area product (DAP) for chest, abdomen, bone, and fluoroscopy radiography by age groups. Results: Data were collected for a total of 780 patients. 360 x-rays, 100 fluoroscopy and 320 tomography scans. Reference levels of radiation dose used in the hospital were found to be low compared to European guidelines of 2018 reference levels. DRLs are described for each study and age group. Conclusion: It was demonstrated that at the hospital where the study was conducted, reference levels of radiation in the pediatric population are low. This work can serve as a national reference.


Subject(s)
Multidetector Computed Tomography , Radiation Dosage , Radiation Protection
17.
Rev. chil. endocrinol. diabetes ; 13(4): 159-165, 2020. tab, graf
Article in Spanish | LILACS | ID: biblio-1123622

ABSTRACT

Introducción: El cáncer diferenciado de tiroides (CDT), es actualmente la neoplasia endocrina más frecuente. Su tratamiento estándar es la resolución quirúrgica, asociado a ablación con radioyodo (RI) según la clasificación propuesta por la American Thyroid Association (ATA). Las indicaciones y dosis de este último, han ido variando en los últimos años según avanzan las investigaciones en este ámbito. Objetivo: En el siguiente estudio se compararon las dosis de RI utilizadas previo y posterior a la implementación de las últimas guías de la ATA. Materiales y métodos: Estudio retrospectivo observacional de 70 pacientes con diagnóstico de CDT del Hospital Clínico de la Universidad de Chile entre 2012 y 2017. Se agruparon los pacientes en dos cohortes, los operados entre los años 2012-2015 y los 2016-2017 clasificándolos según riesgo ATA, TNM y riesgo de recurrencia. Se consignaron las dosis de RI utilizadas y se compararon entre las cohortes. Análisis estadístico: Mann Whithney. Resultados: Al comparar la dosis de RI entre ambas cohortes, según TNM y riesgo ATA, se obtuvo los siguientes resultados: los pacientes T1b de la cohorte 2012-2015 presentaron dosis de RI significativamente mayores que los de la cohorte 2016-2017; también se evidenció que en pacientes N0 hubo una diferencia estadísticamente significativa, mostrando una tendencia a disminuir la dosis de RI; además, en los pacientes de la cohorte 2012-2015 con riesgo ATA intermedio, se obtuvo que las dosis de RI fueron significativamente mayores que las utilizadas en la cohorte 2016-2017. Conclusión: Se concluye que las variaciones de las dosis de RI utilizadas en pacientes con CDT en un hospital universitario van acorde a las recomendaciones internacionales actuales, particularmente la publicación de la guía ATA 2015, aplicándose radioablación con menor dosis de RI. Dado este cambio, se ha evidenciado igualdad de efectos con dosis menores de RI y consecuentemente menos efectos adversos.


Introduction: Differentiated thyroid cancer (CDT) is currently the most frequent endocrine neoplasia. Its standard of care is surgical treatment, associated with radioiodine ablation (IR) according to the classification proposed by the American Thyroid Association (ATA). The indications and doses of the latter have changed in recent years as research in this area advances. Objective: In the following study, the doses of IR used before and after the implementation of the latest ATA guidelines were compared. Materials and methods: Retrospective observational study of 70 patients with a diagnosis of CDT from the Clinical Hospital of the University of Chile between 2012 and 2017. Patients were grouped into two cohorts, those surgically intervened between the years 2012-2015 and 2016-2017, classifying them according to ATA risk, TNM and recurrence risk. The IR doses used were reported and compared between the cohorts. Statistical analysis: Mann Whithney. Results: When comparing the IR dose between both cohorts, according to TNM and ATA risk, the following results were obtained: T1b patients in the 2012-2015 cohort had significantly higher IR doses than those in the 2016-2017 cohort; It was also evidenced that N0 patients showed a statistically significant tendency to decrease the IR dose; In addition, the 2012-2015 cohort with intermediate ATA risk, revealed IR doses significantly higher than those used in the 2016-2017 cohort. Conclusion: It is concluded that the variations in IR doses, used in patients with CDT in a university hospital, are in accordance with current international recommendations, particularly the publication of the ATA 2015 guidelines, applying radioablation with a lower dose of IR. Given this change, equality of effects has been evidenced with lower doses of IR and consequently fewer adverse effects.


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Radiation Dosage , Radiotherapy/standards , Thyroid Neoplasms/radiotherapy , Endocrinology/standards , Iodine Radioisotopes/administration & dosage , Thyroidectomy/methods , Thyroid Neoplasms/surgery , Retrospective Studies , Cohort Studies , Practice Guidelines as Topic , Risk Assessment , Radiotherapy, Adjuvant , Endocrinology/methods , Ablation Techniques/methods , Iodine Radioisotopes/adverse effects
20.
Article in Chinese | WPRIM | ID: wpr-828899

ABSTRACT

To explore a method for calculating water equivalent diameter () based on localizer CT images for calculation of the size specific dose estimates (SSDE).GE Revolution CT and LightSpeed VCT were used to scan CT dose index phantoms 16 cm and 32 cm in diameter at the tube voltages of 80, 100 and 120 kV to obtain the axial image and anteroposterior localizer radiograph. According to the definition of CT Hounsfield unit, the axial images were used to calculate the conversion factors that convert the phantom thickness to water equivalent thickness. The gray value of the localizer radiograph and the water equivalent thickness were calibrated with a linear equation, and the parameters of the calibration were used to calculate the water equivalent thickness. The method was verified using 2 CT dose index phantoms and in 22 patients undergoing chest and abdominal CT examination.Comparison of the water equivalent diameter () based on the localizer radiograph and axial image of the 2 phantoms showed that the percentage difference between from the axial images and from the localizer radiograph was below 3%. The trend of variations with location in the two methods was sonsistent. The difference in in intermediate region of interest between the axial image and the localizer radiograph from the 22 patients was below 6.6%. With the mean in the ROI, the maximum percentage difference was 7.5%.Calibration of the gray value of the localizer radiograph and the water equivalent thickness using the axial image and localizer radiograph of CT dose index phantoms allows quick calculation of the SSDE based on the parameters of calibration.


Subject(s)
Calibration , Humans , Phantoms, Imaging , Radiation Dosage , Tomography, X-Ray Computed , Water
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