ESS - RAD - Radiologia
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- Morphological Dynamic Study of Human Vocal TractPublication . Ventura, Sandra Rua; Freitas, Diamantino RuiMagnetic resonance imaging (MRI) has been successfully used in speech research, with the development of high B-value units and ultra-fast acquisition sequences, to obtain morphological and dynamic data of the vocal tract. This knowledge is useful for the understanding of speech mechanisms and can, in particular be employed for speech synthesis. The aim of our study was a combination of the morphological and dynamical characterizations of speech, resulting in the production of 3D articulatory models of some relevant Portuguese sounds and syllables. A set of static images in stacks and dynamic sequences were collected during the experiments from subjects that were instructed to vocalize during the acquisition, exploring the capabilities of the equipment. Analysis of the image stacks allowed the extraction of the vocal tract contours and a subsequent non-conventional 3D reconstruction by means of combination of orthogonal stacks allowed visualization and partial measurement of the sampled vocal tract shape.
- Morphological Dynamic Study of Human Vocal TractPublication . Ventura, Sandra Rua; Freitas, Diamantino RuiWith the development of high B-value units and ultra-fast acquisition sequences, magnetic resonance imaging (MRI) has been successfully used in speech research to obtain morphological and dynamic data of the vocal tract
- Modelos morfológicos tridimensionais por IRM do tracto vocal para as principais vogais do Português EuropeuPublication . Ventura, Sandra Moreira Rua; Freitas, Diamantino RuiO entendimento da produção da fala tem sido ampla mente procurado, recorrendo à imagem por ressonância magnética (IRM), mas não é totalmente conhecido, particularmente no que diz respeito aos sons do Português Europeu (PE). O principal objectivo deste estudo foi a caracterização das vogais do PE. Com base na IRM recolheram-se conjuntos de imagens bidimensionais, em cinco posições articulatórias distintas, durante a produção sustentada do som. Após extracção de contornos do tracto vocal procedeu-se à reconstrução tridimensional, constatando-se que a IRM fornece in formação morfológica útil e com considerável precisão acerca da posição e forma dos diferentes articuladores da fala.
- Three-dimensional modeling of tongue during speech using MRI dataPublication . Ventura, Sandra Moreira Rua; Freitas, Diamantino Rui; Tavares, João ManuelThe tongue is the most important and dynamic articulator for speech formation, because of its anatomic aspects (particularly, the large volume of this muscular organ comparatively to the surrounding organs of the vocal tract) and also due to the wide range of movements and flexibility that are involved. In speech communication research, a variety of techniques have been used for measuring the three-dimensional vocal tract shapes. More recently, magnetic resonance imaging (MRI) becomes common; mainly, because this technique allows the collection of a set of static and dynamic images that can represent the entire vocal tract along any orientation. Over the years, different anatomical organs of the vocal tract have been modelled; namely, 2D and 3D tongue models, using parametric or statistical modelling procedures. Our aims are to present and describe some 3D reconstructed models from MRI data, for one subject uttering sustained articulations of some typical Portuguese sounds. Thus, we present a 3D database of the tongue obtained by stack combinations with the subject articulating Portuguese vowels. This 3D knowledge of the speech organs could be very important; especially, for clinical purposes (for example, for the assessment of articulatory impairments followed by tongue surgery in speech rehabilitation), and also for a better understanding of acoustic theory in speech formation.
- Estudo do Stress nos Técnicos de RadiologiaPublication . Videira, Sara; Ventura, Sandra RuaO conceito de stress nem sempre foi consensual, no entanto, vários estudos têm documentado a relevância deste no contexto das diferentes profissões. O stress parece ser particularmente importante quando aplicado aos profissionais de saúde, estes estão frequentemente propensos ao burnout, termo que descreve o estado deexaustão prolongada e diminuição de interesse, especialmente em relação ao trabalho.
- Standards e Guidelines em RadiologiaPublication . Rodrigues, Anabela; Ventura, Sandra RuaPela diversidade da formação dos técnicos de Radiologia, torna-se útil o recurso a ferramentas próprias e específicas para cada estudo em particular, facilitando a sua realização e possibilitando a obtenção de informação com a qualidade diagnóstica esperada/necessária.
- Magnetic resonance imaging of the vocal tract: techniques and applicationsPublication . Ventura, Sandra Moreira Rua; Freitas, Diamantino Rui; Tavares, João ManuelMagnetic resonance (MR) imaging has been used to analyse and evaluate the vocal tract shape through different techniques and with promising results in several fields. Our purpose is to demonstrate the relevance of MR and image processing for the vocal tract study. The extraction of contours of the air cavities allowed the set - up of a number of 3D reconstruction image stacks by means of the combination of orthogonally oriented sets of slices for e ach articulatory gesture, as a new approach to solve the expected spatial under sampling of the imaging process. In result these models give improved information for the visualization of morphologic and anatomical aspects and are useful for partial measure ments of the vocal tract shape in different situations. Potential use can be found in Medical and therapeutic applications as well as in acoustic articulatory speech modelling.
- Application of MRI and Biomedical Engineering in Speech Production StudyPublication . Ventura, Sandra Moreira Rua; Freitas, Diamantino Rui; Tavares, João ManuelSpeech production has always been a subject of interest both at the morphological and acoustic levels. This knowledge is useful for a better understanding of all the involved mechanisms and for the construction of articulatory models. Magnetic resonance imaging (MRI) is a powerful technique that allows the study of the whole vocal tract, with good soft tissue contrast and resolution, and permits the calculation of area functions towards a better understanding of this mechanism. Thus, our aim is to demonstrate the value and application of MRI in speech production study and its relationship with engineering, namely with biomedical engineering. After vocal tract contours extraction, data were processed for 3D reconstruction culminating in model construction of some of the sounds of European Portuguese. MRI provides useful morphological data about the position and shape of the different speech articulators, and the biomedical engineering computational tools for its analysis.
- Analysis of tongue shape and motion in speech production using statistical modelingPublication . Vasconcelos, Maria João; Ventura, Sandra Moreira Rua; Tavares, João Manuel; Freitas, Diamantino RuiThe mechanisms of speech production are complex and have been raising attention from researchers of both medical and computer vision fields. In the speech production mechanism, the articulator’s study is a complex issue, since they have a high level of freedom along this process, namely the tongue, which instigates a problem in its control and observation. In this work it is automatically characterized the tongues shape during the articulation of the oral vowels of Portuguese European by using statistical modeling on MR-images. A point distribution model is built from a set of images collected during artificially sustained articulations of Portuguese European sounds, which can extract the main characteristics of the motion of the tongue. The model built in this work allows under standing more clearly the dynamic speech events involved during sustained articulations. The tongue shape model built can also be useful for speech rehabilitation purposes, specifically to recognize the compensatory movements of the articulators during speech production.
- The use and relevance of gonad protection shields in children during hips radiographyPublication . Silva, C. A.; Silva, P. N.; Ventura, Sandra Moreira RuaConsidering that ionizing radiation effects are cumulative and the gonads are particularly sensitive to these effects, and also the clinical importance of pelvic radiographs in children, the excess of radiation exposure to the gonads must be avoided. The purpose of this study is to demonstrate the relevance of the correct use of gonad protection shields and to evaluate their use on the hip radiographs performed in a reference clinical institution, through the retrospective analysis of pelvic radiographic images performed in children. According the image quality assessment, 20 (40%) patients were unprotected and gonads shields were incorrectly placed in 24 (80%) patients.