OBJETIVO: Avaliar a dose efetiva recebida pelos trabalhadores envolvidos na realização de procedimentos de hemodinâmica, de forma a estabelecer parâmetros comparativos entre os dados obtidos com uma câmara de ionização e pelos dosímetros usados para monitoração individual. MATERIAIS E MÉTODOS: A avaliação foi desenvolvida em um serviço de hemodinâmica, sendo que os testes constaram da medida do taxa de kerma no ar no ambiente real de trabalho, na posição ocupada por médicos e enfermeiros, com e sem a utilização de barreira plumbífera de proteção. Foi levado em consideração o número de exames realizados no serviço e foram selecionados as projeções e parâmetros radiográficos mais utilizados. Para a estimativa da dose efetiva foram utilizados fatores de conversão encontrados na literatura. RESULTADOS: Os valores encontrados em dose efetiva e de dosimetria são consistentes. Observou-se, ainda, que o uso da barreira protetora plumbífera reduz em até 97% a dose recebida pelo profissional, devendo esta ser utilizada na rotina de exames. CONCLUSÃO: Os valores apresentados são representativos, não podendo ser assumidos como reprodução das condições de monitoração individual, mas são válidos para comparações e orientação na otimização das doses.

OBJECTIVE: This study aims to evaluate the effective ionizing radiation dose received by staff involved in interventional vascular procedures to establish parameters for comparison between the data obtained with an ionization chamber and with the dosimeters used for individual monitoring. MATERIALS AND METHODS: The evaluation was performed in a cardiac catheter laboratory and air kerma rate was measured in a real working environment, in the positions occupied by physicians and nurses, with and without the lead glass shield. The number of tests performed in the laboratory was taken into consideration and most common projections and radiographic parameters were selected. Conversion factors founded in the literature were applied for the effective dose estimation. RESULTS: The values found in the effective dose and in the dosimetry report were rather consistent. Additionally, it was observed that the use of the lead glass shield reduces in up to 97% the doses received by the professional and therefore it must be routinely used. CONCLUSION: The reported values are representative but cannot be assumed as a reproduction of individual monitoring conditions, although they are valid for comparison purposes and as a guidance for dosing optimization.

Recent development and studies of physical and chemical properties of the conducting polymers have been calling the interest of many scientists. Among this group of materials, the polyaniline (PANI) deserves special attention because of its high chemical and thermal stability under normal conditions, simple process of polymerization and low cost. This polymer is also known due to its strongly pronounced and well studied electrochemical characteristics. In the present work, the variations of the electrical resistance of polyaniline caused by X-rays radiation have been studied. The polymer has been synthesized by electrochemical method in stainless steel and graphite electrodes. The data concerning the electrical resistance of PANI were measured just after the synthesis. This has been performed in the water solution of sulfuric acid within monomer of aniline where the polyaniline has been submitted to the applied voltages in the range from 200mV to 600mV. Polymeric samples have been irradiated using the X-rays with the energy 50keV and 100keV. After the irradiation, the electrical measurements have been repeated. The whole experimental procedure was performed several times. The obtained results have clearly shown the potential of polyaniline as a dose sensitive material that could be applied as a radiation sensor.

The use of protons instead of X-rays for computerized tomography (CT) studies has potential advantages, especially for medical applications in proton treatment planning. However, the spatial resolution of proton CT is limited by multiple Coulomb scattering (MCS). We used the Monte Carlo simulation tool GEANT4 to study the resolution achievable with different experimental arrangements of a proton CT scanner. The passage of a parallel 200MeV proton beam through a virtual cylindrical aluminum phantom with 50mm external diameter was simulated. In our study, the phantom contained a set of cylindrical holes with diameters ranging from 4mm to 0.5mm. The GEANT4 simulation consisted of a series of 180 projections at 2 degree intervals with 350 proton track histories for each one. The fi ltered back projection algorithm was used to reconstruct a 2D tomographic image of phantom.

Este trabalho apresenta o resultado do estudo para elaboração de um programa computacional para avaliação e controle de serviços de radiologia médica de médio porte, de acordo com as recentes diretrizes de proteção radiológica do Ministério da Saúde. A rotina do Departamento de Radiologia do Hospital São Vicente de Paulo, Passo Fundo, RS, foi analisada, e a partir desta análise foi desenvolvido um programa computacional utilizando-se ferramentas de computação padrão Windows. O programa, chamado de "Sistema Radiológico", foi implementado e testado com dados e medições, ficando comprovado que a metodologia permite o acompanhamento dos requisitos da Portaria nº 453 do Ministério da Saúde e possibilita ganho de eficiência em diversas atividades.

We present the results of a study for the development of a computational program for the evaluation and control of medium size medical radiological facilities in agreement with the recent guidelines of radiological protection of the Brazilian Ministry of Health. The routine procedures of the Radiology Department of Hospital São Vicente de Paulo, Passo Fundo, RS, Brazil, were analyzed and a computer program was developed using Windows tools. The program named "Sistema Radiológico" (Radiological System) was implemented and tested with data and measurements. The results proved that the methodology employed allows fulfillment of the requirements of the Directive nº 453 of the Brazilian Ministry of Health, and moreover, increases the efficiency of several other activities in the radiology department.