Collimators
Mostrando 1-12 de 12 artigos, teses e dissertações.
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1. Evaluation of the scattered radiation components produced in a gamma camera using Monte Carlo method
INTRODUCTION: This paper presents a simulation for evaluation of the scattered radiation components produced in a gamma camera PARK using Monte Carlo code SIMIND. It simulates a whole body study with MDP (Methylene Diphosphonate) radiopharmaceutical based on Zubal anthropomorphic phantom, with some spinal lesions. METHODS: The simulation was done by comparin
Rev. Bras. Eng. Bioméd.. Publicado em: 2014-06
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2. Performance assessment of the single photon emission microscope: high spatial resolution SPECT imaging of small animal organs
The single photon emission microscope (SPEM) is an instrument developed to obtain high spatial resolution single photon emission computed tomography (SPECT) images of small structures inside the mouse brain. SPEM consists of two independent imaging devices, which combine a multipinhole collimator, a high-resolution, thallium-doped cesium iodide [CsI(Tl)] col
Braz J Med Biol Res. Publicado em: 06/11/2013
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3. A clinical gamma camera-based pinhole collimated system for high resolution small animal SPECT imaging
The main objective of the present study was to upgrade a clinical gamma camera to obtain high resolution tomographic images of small animal organs. The system is based on a clinical gamma camera to which we have adapted a special-purpose pinhole collimator and a device for positioning and rotating the target based on a computer-controlled step motor. We deve
Brazilian Journal of Medical and Biological Research. Publicado em: 2010-12
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4. Methodological approaches to planar and volumetric scintigraphic imaging of small volume targets with high spatial resolution and sensitivity
Single-photon emission computed tomography (SPECT) is a non-invasive imaging technique, which provides information reporting the functional states of tissues. SPECT imaging has been used as a diagnostic tool in several human disorders and can be used in animal models of diseases for physiopathological, genomic and drug discovery studies. However, most of the
Brazilian Journal of Medical and Biological Research. Publicado em: 2009-08
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5. Implementação e aceite de sistema de radioterapia de feixe modulado dinâmico com o uso de colimador secundário de múltiplas folhas / Commisioning and implantation of the dynamic intensity modulated radiation therapy using secondary multi-leaf collimator (MLC)
A radioterapia de feixe de intensidade modulada (IMRT) no seu modo dinâmico é uma forma de radioterapia tri-dimensional (3D), na qual modula-se um feixe de forma a obter-se a irradiação com campos que possuem perfil variável. Os campos são gerados por um sistema de otimização matemático e transformado em seqüências de movimento ou abertura de lâm
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 14/10/2008
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6. Assessment of radiotherapic treatments with thermoluminescent dosimetry / Verificação de tratamentos radioterápicos diversos com dosimetria termoluminescente
The last decades noticed a massive improvement in radiotherapy techniques and the use of segmented beams produced by multileaf collimators. However, the dose radiation therapy planning systems (TPS) in use are characterized by the restriction of access to the calculation algorithms. The aim of this work was to compare dose values measured in an anthropomorph
Publicado em: 2007
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7. Intercomparação de colimadores de múltiplas lâminas para implementação de terapia de feixes de intensidade modulada / Multileaf collimator intercomparison for intensity modulated radiation therapy implementation
Neste trabalho é apresentada uma intercomparaçào das características dosimétricas entre três sistemas de colimadores multi-lâminas: Varian Millenium com 120 lâminas, mMLC m3 Brainlab e Varian Mark II ambos com 52 lâminas. A largura da projeção das lâminas no isocentro e na região central do campo é de 0,5 cm; 0,35 cm e 1,0 cm respectivamente. F
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 10/01/2006
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8. Proton CT setup at CV-28 of IEN/CNEN
Although the idea of proton Computed Tomography (pCT) is not new, it is currently not available. It is still unknown if the image quality of pCT is sufficient for localizing tumors and if the accuracy of proton range calculations surpass that of X-ray CT based range calculations without significantly increasing the patient exposure. The spatial resolution of
Brazilian Journal of Physics. Publicado em: 2005-09
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9. UtilizaÃÃo da sonda a cintilaÃÃo na captaÃÃo de 131I pela TireÃide / Use of gamma probe in 131I thyroid uptake studies
Evaluation of thyroid uptake by administration of radioactive iodine is a well-defined procedure to assess patient thyroid function. In general, nuclear medicine institutions use gamma cameras coupled to pinhole collimators to perform uptake studies. With the growing use of intraoperative gamma probes in the radioguided surgical techniques, several instituti
Publicado em: 2002
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10. Minitomografo de raio-X e raio-gama computadorizado para aplicações multidisciplinares
The main result of this thesis is the development, implementation and use of an X-ray and y-ray computerized minitomography scanner with possible applications in multidisciplinary fields particularly in soil physics. The hardware is basically a mechanical table with two step motors, one for rotation and another for translation motions, radioactive,source, co
Publicado em: 1987
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11. Collimation and surface counting in haematology
The effect on the results obtained in surface counting investigations of using a dual detector counting system and multihole collimators has been investigated. The use of the additional detector results in smoother curves for the uptake of the radionuclide and the use of multihole collimators increases the discrimination of the counting system against the ef
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12. Secondary neutron spectra from modern Varian, Siemens, and Elekta linacs with multileaf collimators
Neutrons are a by-product of high-energy x-ray radiation therapy (threshold for [γ,n] reactions in high-Z material ∼7 MeV). Neutron production varies depending on photon beam energy as well as on the manufacturer of the accelerator. Neutron production from modern linear accelerators (linacs) has not been extensively compared, particularly in terms of the
American Association of Physicists in Medicine.