Effect of Clinician-directed Technical Specifications on Entrance Skin Doses in Neonates

Objectives: To compare the entrance skin doses (ESD) before and after implementation of a radiation safety policy in neonates (RSN), which focused on clinician-directed technical specifications on the digital X-ray machine. Methods: Prospective observations included two sets of X-rays: Before (BRSN) and after (ARSN) implementation of RSN (documented indication for Xray/expected posttest findings, settings of 40 kVp, 0.5 mAs, film-focus distance 100 cm, gonadal-shield, optimal collimation, and post-shoot image-enhancement). Results: 33 and 32 X-rays were analyzed in respective groups. Mean (SD) of calculated and machine-quantified ESD (µGy/m2) was higher in BRSN group as compared to ARSN group (P <0.001). All ARSN X-rays were interpretable for expected post-test findings. Conclusion: Clinicians’ cognizance of ability to make consequential bedside technical specifications, can reduce ESD without affecting interpretability. These single observations could have a larger impact in sick neonates, where multiple X-rays are done.

Computed tomography with low-dose radiation versus standard-dose radiation for diagnosing fractures: systematic review and meta-analysis

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.

Estudo da dose nos exames de tomografia computadorizada abdominal em um equipamento de 6 cortes / Dosimetry in abdominal imaging by 6-slice computed tomography

OBJETIVO: Determinar a dose efetiva recebida nos exames de tomografia computadorizada abdominal e estudar a influência das características dos pacientes na dose recebida. MATERIAIS E MÉTODOS: Foram realizadas medições dos valores de dose com uma câmara de ionização em objetos simuladores, de forma a verificar se os valores obtidos estavam de acordo com os valores apresentados pelo equipamento de tomografia computadorizada e se estes não ultrapassavam os níveis de referência de dose recomendados. Posteriormente, foram medidos os valores de dose recebida pelos pacientes, com autonomia física, nos exames de tomografia computadorizada abdominal (n = 100) e a relação existente com as suas características antropométricas. Por último, foi simulada a dose nos órgãos por meio do método de Monte Carlo utilizando o software de simulação CT-Expo V 1.5, e estudado o efeito do controle automático de exposição nestes exames. RESULTADOS: As principiais características com influência direta na dose são a massa corporal, o perímetro abdominal e o índice de massa corporal do paciente, cuja relação é linear e positiva. CONCLUSÃO: A dose de radiação recebida nos exames abdominais depende de algumas características dos pacientes, sendo importante ajustar os parâmetros de aquisição às suas dimensões.

OBJECTIVE: To determine the effective dose in abdominal computed tomography imaging and to study the influence of patients' characteristics on the received dose. MATERIALS AND METHODOS: Dose values measurements were performed with an ionization chamber on phantoms to check the agreement between dose values and those presented by the computed tomography apparatus, besides their compliance with the recommended reference dose levels. Later, values of dose received by physically able patients submitted to abdominal computed tomography (n = 100) were measured and correlated with their anthropometric characteristics. Finally, the dose to organs was simulated with the Monte Carlo method using the CT-Expo V 1.5 software, and the effect of automatic exposure control on such examinations. RESULTS: The main characteristics directly influencing the dose include the patients' body mass, abdominal perimeter and body mass index, whose correlation is linear and positive. CONCLUSION: The radiation dose received from abdominal CT scans depends on some patient's characteristics, and it is important to adjust the acquisition parameters to their dimensions.

Os efeitos da radiação diagnóstica / The effects of diagnostic radiation / Los efectos de la radiación diagnóstica

Após haver a exposição à bomba atômica no Japão, calcula-se que, em aproximadamente 100 mSv, a radiação produz danos no organismo, entre os quais estão os cânceres radioinduzidos. A radiação de diagnóstico tem uma categoria de dose abaixo de 100 mSv. Os efeitos da radiação a essas doses são baseados em estimativas; contudo, deve-se levar em consideração que as doses são acumulativas. Neste artigo, comenta-se sobre os riscos da radiação de diagnóstico e chama-se a atenção à racionalização do uso das pesquisas radiológicas e à aplicação dos critérios ALARA (as low as reasonably achievable).

After the exposition to the atomic bomb in Japan, it is calculated that over 100 mSv are the quantity of damage produced by radiation in the organism, among which it can be found radio induced cancers. The diagnostic radiation has a doses average that is below 100 mSv. The radiation effects to these doses are based on estimations; however, one should know that the doses are accumulative. In this article, diagnostic radiation risks are commented and it calls the attention to rationalizing the use of radiological explorations and to applying ALARA criteria.

Tras la exposición a la bomba atómica en Japón, se ha calculado que, por encima de 100 mSv, la radiación produce daños en el organismo, entre los que se encuentran los cánceres radioinducidos. La radiación diagnóstica tiene un rango de dosis que está por debajo de 100 mSv. Los efectos de la radiación a esta dosis se basan en estimaciones; sin embargo, hay que tener en cuenta que las dosis son acumulativas. En este artículo, se comentan los riesgos de la radiación diagnóstica y se hace una llamada de atención a la racionalización del uso de las exploraciones radiológicas y a la aplicación de los criterios ALARA (as low as reasonably achievable).

Otimização da dose em exames de rotina em tomografia computadorizada: estudo de viabilidade em um Hospital Universitário / Radiation dose optimization in routine computed tomography: a study of feasibility in a University Hospital

OBJETIVO: Estudar a viabilidade de redução da dose de radiação em protocolos de aquisição de imagens de tomografia helicoidal em um hospital universitário. MATERIAIS E MÉTODOS: Foi realizado levantamento de dose de radiação de protocolos de tomografia com objetos simuladores e câmara de ionização. Foram propostas variações de kVp e mAs, determinando-se a média de ruído. Protocolos com valores de ruído menores ou iguais a 1 por cento foram submetidos à avaliação qualitativa de contraste e resolução espacial por três observadores. RESULTADOS: Foram realizados 22 testes de variações para o protocolo de crânio pediátrico, 26 para crânio adulto, 28 para abdome e 18 para tórax. A redução da dose conseguida variou entre 7,4-13 por cento para protocolo de crânio pediátrico, 3,8-25 por cento para crânio adulto, 9,6-34,3 por cento para abdome e 6,4-12 por cento para tórax. Notou-se também que a utilização de ferramentas de janelamento e zoom favoreceu o aceite das imagens pelos observadores. CONCLUSÃO: É possível reduzir os níveis de dose de radiação em até 34,4 por cento, comparativamente aos protocolos utilizados na rotina, mantendo-se o ruído em níveis aceitáveis. O uso de ferramentas de manipulação digital das imagens possibilitou a aceitação de imagens com níveis maiores de ruído, favorecendo o processo de redução de dose de radiação.

OBJECTIVE: To study the feasibility of reducing radiation dose in protocols for acquisition of helical computed tomography images in a University Hospital. MATERIALS AND METHODS: A survey of radiation doses in computed tomography protocols was performed with phantoms and ionization chamber. Changes in kVp and mAs were proposed, determining the average noise. Protocols with noise values 1 percent were submitted to qualitative assessment of contrast and spatial resolution by three observers. RESULTS: Tests of variations were performed with 22 protocols for pediatric skulls, 26 for adult skulls, 28 for abdomen, and 18 for chest. The reduction in dose achieved ranged between 7.4 percent and13 percent for pediatric skull, 3.8 percent and 25 percent for adult skull, 9.6 percent and 34.3 percent for abdomen, 6.4 percent and 12 percent for chest. It was also noted that the use of windowing and zoom tools supported the acceptance of images by the observers. CONCLUSION: Radiation dose levels can be reduced by up to 34.4 percent in comparison with routine protocols, keeping the noise at acceptable levels. The use of digital manipulation tools allowed the acceptance of images with higher noise levels, thus resulting in radiation dose reduction.

Radiation protection in dental clinic / 대한구강악안면방사선학회지

Although the diagnostic information provided by radiographs may be of definite benefit to the patients, the radiographic examination does carry the potential for harm from exposure to ionizing radiation. Therefore we should try to expose radiation as low as reasonably achievable and to give diagnostic information to patients as much as possible. All of dentists should have competence in radiation protection. I wish to deal with what we should do for the optimization of radiation protection in dental clinic.