RESUMO
A system has been developed for the three-dimensional (3D) visualization of the face and skull using data obtained from a purpose-built no-contact laser scanning system and from a series of scans produced by X-ray computerized tomography. Features developed allow the simulation, planning and prediction of maxillo-facial surgery. Realistic skeletal and facial images with a solid 3D appearance are produced from these two datasets using computer graphics techniques. The images can be sectioned for diagnostic purposes or parts can be repositioned for the simulation of surgery. 3D measurements can be made on the images for pre- and post-surgical analysis. An example of the clinical use of the system in the planning of surgery and the prediction of post-surgical facial appearance is given.
Assuntos
Simulação por Computador , Face/cirurgia , Lasers , Procedimentos Cirúrgicos Ortognáticos , Tomografia Computadorizada por Raios X , Gráficos por Computador , Face/diagnóstico por imagem , Humanos , Processamento de Imagem Assistida por Computador , Arcada Osseodentária/diagnóstico por imagem , Minicomputadores , Planejamento de Assistência ao Paciente , Cuidados Pré-OperatóriosRESUMO
Many different data representations are possible in computer graphics. Originally, in the medical field, simplified methods were used in order to reduce computation times on small computer systems. Currently a wider range of techniques is developing as costs of hardware continue to fall. In this paper we review a number of possible representations and explain the advantage of one that is greyscale, volumetric and random access. Different segmentation techniques can be used, as well as shading algorithms that give greatly improved appearances. A quantitative analysis of shading methods is derived in terms of the degree of sampling of the 'pseudo-normal' vectors that estimate the direction of the tangent to a surface. The application to a study of multiple sclerosis lesions in the brain using nuclear magnetic resonance data is shown.
Assuntos
Gráficos por Computador , Interpretação de Imagem Assistida por Computador , Encéfalo/patologia , Humanos , Imageamento por Ressonância Magnética , Esclerose Múltipla/diagnósticoRESUMO
A computer system has been developed for the simulation of facial surgery with interactive three-dimensional graphic techniques and data derived from computed tomographic scans and a purpose-built laser scanning system. The simulation includes the surgery on the hard tissues, and modeling of the soft tissue for prediction of the postoperative facial appearance. The facilities available are described and an example of their use is given.