10 documents found, page 1 of 1
Striatal dopamine D2-like receptors availability in obesity and its modulation ...
Ribeiro, Gabriela; Maia, Ana; Cotovio, Gonçalo; Oliveira, Francisco P. M.; Costa, Durval C.; Oliveira-Maia, Albino J.There is significant evidence linking a 'reward deficiency syndrome' (RDS), comprising decreased availability of striatal dopamine D2-like receptors (DD2lR) and addiction-like behaviors underlying substance use disorders and obesity. Regarding obesity, a systematic review of the literature with a meta-analysis of such data is lacking. Following a systematic review of the literature, we performed random-effects ...
Evaluation of the attenuation correction on myocardial perfusion imaging: a pha...
Machado, Marisa; Oliveira, Francisco P. M.; Vieira, Lina Oliveira; Costa, Durval C.Myocardial perfusion imaging (MPI) with single-photon emission computed tomography (SPECT) is important for risk stratification of coronary artery disease. MPI quantification obtained from available images may not be accurate due to several potential sources of error, being photon attenuation, especially in overweight patients, a significant problem. Attenuation maps derived from X-ray computed tomography (CT) ...
Imobilização da região da cabeça por prototipagem rápida para fins de diagnósti...
Craveiro, D. S.; Loja, M. A.; Vieira, Lina; Sousa, Eva; Costa, Durval C.; Parafita, Rui; Rodrigues, J. A.Objetivo do estudo: Modelar e testar, por procedimentos de prototipagem rápida, máscaras de imobilização da cabeça através da imagem médica. Conclusões: Dispositivos de imobilização construídos por prototipagem rápida têm características favoráveis para aplicação em imobilização em diagnóstico e terapia. Para dispositivos de imobilização da cabeça as diferenças encontradas na análise estática realizada foram mí...
Comparison between 3D laser scanning and computed tomography on the modelling o...
Sousa, Eva; Vieira, Lina; Costa, D. M.; Costa, Durval C.; Parafita, R.; Loja, M. A.The measurement of people physical parameters and proportions constitutes an important field of science, the anthropometry since it is related to the characterization of the human size and constitution; it allows improving the design and sizing of systems and devices to human use. To enable these measurements, different direct and indirect methodologies may be used depending on the particular aim of a specific ...
The influence of number of counts in the myocardium in the determination of rep...
Vieira, Lina; Costa, Durval C.; Almeida, PedroMyocardial perfusion gated-single photon emission computed tomography (gated-SPECT) imaging is used for the combined evaluation of myocardial perfusion and left ventricular (LV) function. The aim of this study is to analyze the influence of counts/pixel and concomitantly the total counts in the myocardium for the calculation of myocardial functional parameters. Material and methods: Gated-SPECT studies were per...
Monte Carlo simulation of the basic features of the GE Millennium MG single pho...
Vieira, Lina; Vaz, Tânia; Costa, Durval C.; Almeida, P.Objective - To describe and validate the simulation of the basic features of GE Millennium MG gamma camera using the GATE Monte Carlo platform. Material and methods - Crystal size and thickness, parallel-hole collimation and a realistic energy acquisition window were simulated in the GATE platform. GATE results were compared to experimental data in the following imaging conditions: a point source of 99mTc at di...
The influence of count's number in myocardium in the determination of reproduci...
Vaz, Tânia; Vieira, Lina; Sousa, Eva; Costa, Durval C.; Almeida, PedroMyocardial Perfusion Gated Single Photon Emission Tomography (Gated-SPET) imaging is used for the combined evaluation of myocardial perfusion and left ventricular (LV). The purpose of this study is to evaluate the influence of the total number of counts acquired from myocardium, in the calculation of myocardial functional parameters using routine software procedures. Methods: Gated-SPET studies were simulated u...
Image quality of myocardial perfusion-gated studies: effect of ingestion of dif...
Vieira, Lina; Almeida, Pedro; Costa, Durval C.Myocardial perfusion-gated-SPECT (MP-gated-SPECT) imaging often shows radiotracer uptake in abdominal organs. This accumulation interferes frequently with qualitative and quantitative assessment of the infero-septal region of myocardium. The objective of this study is to evaluate the effect of ingestion of different fat content on the reduction of extra-myocardial uptake and to improve MP-gated-SPECT image qual...
Study of the influence of count’s number in myocardium in the determination of ...
Vieira, Lina; Sousa, Eva; Vaz, Tânia; Costa, Durval C.; Almeida, PedroMyocardial Perfusion Gated Single Photon Emission Tomography (Gated-SPET) imaging is used for the combined evaluation of myocardial perfusion and left ventricular (LV) function. But standard protocols of the Gated-SPECT studies require long acquisition times for each study. It is therefore important to reduce as much as possible the total duration of image acquisition. However, it is known that this reduction l...
Estudo da influência do número de ciclos por projecção no cálculo da fracção de...
Vieira, Lina; Faria, Diogo; Patrina, Joana; Nunes, Cátia; Sousa, Diogo; Ribeiro, Liliana; Almeida, Pedro; Costa, Durval C.Introdução - Gated-Single Photon Emission Computed Tomography (Gated-SPECT) do miocárdio usa-se cada vez mais na avaliação conjunta da perfusão do miocárdio e da função ventricular esquerda. O objectivo deste estudo é analisar a possível interferência do número de ciclos cardíacos (ciclos/projecção) e contagens totais por aquisição no cálculo da FEVE (fracção de ejecção do ventrículo esquerdo). Material e métod...