2 resultados para exterior views
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo
Resumo:
Pesquisa documental, de caráter exploratório, que descreve e analisa os enfoques e resultados de um conjunto de estudos sobre a produção científica em Turismo no exterior e no Brasil, com base em levantamento bibliográfico e análise de conteúdo. Com o objetivo de discutir a relevância e o estágio evolutivo do conhecimento turístico, apresenta uma amostra de estudos referenciais sobre o tema no exterior e mapeia 24 estudos produzidos nessa temática no Brasil de 1993 a 2008, destacando diferentes objetivos, objetos de estudo, metodologias e resultados. A maioria das pesquisas no exterior apresenta-se como quantitativa, centra-se em periódicos científicos e destaca-se pelo referencial teórico e a metodologia adotada. No Brasil, embora a maioria das pesquisas privilegie as dissertações e teses acadêmicas enquanto objeto de estudo há maior diversidade deste; nota-se, porém, certo distanciamento em relação ao referencial teórico e metodológico dos estudos do exterior.
Resumo:
Objectives: The objective of this study is to compare subjective image quality and diagnostic validity of cone-beam CT (CBCT) panoramic reformatting with digital panoramic radiographs. Materials and methods: Four dry human skulls and two formalin-fixed human heads were scanned using nine different CBCTs, one multi-slice CT (MSCT) and one standard digital panoramic device. Panoramic views were generated from CBCTs in four slice thicknesses. Seven observers scored image quality and visibility of 14 anatomical structures. Four observers repeated the observation after 4 weeks. Results: Digital panoramic radiographs showed significantly better visualization of anatomical structures except for the condyle. Statistical analysis of image quality showed that the 3D imaging modalities (CBCTs and MSCT) were 7.3 times more likely to receive poor scores than the 2D modality. Yet, image quality from NewTom VGi® and 3D Accuitomo 170® was almost equivalent to that of digital panoramic radiographs with respective odds ratio estimates of 1.2 and 1.6 at 95% Wald confidence limits. A substantial overall agreement amongst observers was found. Intra-observer agreement was moderate to substantial. Conclusions: While 2D-panoramic images are significantly better for subjective diagnosis, 2/3 of the 3D-reformatted panoramic images are moderate or good for diagnostic purposes. Clinical relevance: Panoramic reformattings from particular CBCTs are comparable to digital panoramic images concerning the overall image quality and visualization of anatomical structures. This clinically implies that a 3D-derived panoramic view can be generated for diagnosis with a recommended 20-mm slice thickness, if CBCT data is a priori available for other purposes.