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U Tiede

Publications and source records attributed to U Tiede.

10 recordsLinked to original sources
PubMed1997

Applications and perspectives in anatomical 3-dimensional modelling of the visible human with VOXEL-MAN.

Up to now computerized interactive 3-dimensional (3D) atlases of human anatomy have been based on radiological data or artificial geometric models as spatial descriptions of morphological structures. Besides the obvious advantages of this data (e.g. already in digital format, geometrical correctness) the lack of high resolution anatomical slices of larger regions of the human body has prevented the use of more realistic anatomical data so far. Now, the Visible Human Project offers high quality anatomical slices of complete cadavers. Therefore, on the one hand, new opportunities for realistic virtual 3D models of anatomy are open. On the other hand, just the major advantages of the visible human data (e.g. realistic colors and textures, high resolution) result in new demands on the image processing and visualization techniques. This paper describes experience, solutions and results with a volume-based approach for building realistic anatomical 3D models.

Anatomy, Cross-Sectional↗
PubMed1995

[New kinds of 3-dimensional atlases of the anatomy and function of the human body].

It is a drawback of classical multimedia programs for the visualization of spatial knowledge, that they are based on a limited number of predefined views. This paper describes a model that combines pictorial and symbolic knowledge about spatial structures in a way that allows arbitrary views of the scene and the interrogation of the model in the context of the actual view. The style of the pictorial presentation only depends on the objective and the phantasy of the user. The functionality of the approach is demonstrated with the example of the human head. It is furthermore shown that the model potentially allows the simulation or generation of all classical visual teaching aids for anatomy.

Anatomy, Artistic↗
PubMed1994

A new method for practicing exploration, dissection, and simulation with a complete computerized three-dimensional model of the brain and skull.

In current practice, anatomical atlases are based on a collection of planar images presented in a book or, recently, stored on digital media. We present a new kind of interactive true three-dimensional (3D) anatomical atlases based on a volume model derived from MRI and CT. The model has a two-layer structure. The lower level is a volume model with a set of semantic attributes connected to each voxel. The semantic attributes are assigned by an anatomist using a volume editor. THe upper level represents a set of relations between these attributes. Interactive visualization tools such as multiple surface display, preparation of transparent material and cutting are provided. It is shown that the combination of this model with advanced tools for volume visualization provides the 'look and feel' of real dissection. The system therefore represents a bridge between real dissection of a cadaver and textbooks and classical atlases of anatomy. First tests have shown that the atlas system may be used successfully for teaching anatomy, but also as a reference for radiologists or surgeons. The powerful underlying data structure potentially includes all classical visual teaching aids. As a replacement of classical atlases, however, spatial resolution has still to be improved.

Anatomy↗
PubMed1992

[3-D visualization of dose distributions in CT image volumes].

The 3D-visualization of the entire spatial radiation dosage in cooperation with the 3D-radiation volume requires several data volumes. The structure of the interface between the 3D-treatment planning program "ProPlan" and the 3D-imaging system "VOXEL-MAN" is explained. The first results in the radiological application point out the possibilities of the complex registration of dose distributions and the critical examination of the irradiation technique.

Female↗
PubMed1991

Improvement of 3D acquisition and visualization in MRI.

Three-dimensional (3D) visualization techniques are becoming an ever more important aid in the interpretation of tomographic data. Up to now, however, they have not received widespread use in MRI, because both acquisition and visualization techniques have been inadequate. In this paper we describe new 3D acquisition techniques which can acquire up to 128 slices with a resolution of 256 x 256 pixels in from 8 to 20 min. These techniques produce 3D data sets with excellent contrast and few motion artifacts, which are very well suited for 3D visualization techniques. For the visualization we investigate several rendering techniques, describe some improvements and compare their results. We found that there is no single method which renders all objects equally well. We show which shading method is best suited for different objects and why the other methods fail. Our studies suggest that in a 3D view with several objects each object should be rendered with a separate shading method. In so doing, 3D views can be generated which look like the real human anatomy.

Data Display↗
PubMed1991

[3D displays for craniofacial surgery].

3D visualisation from tomographic image sequences has turned out to be a useful addition to diagnosis and surgical planning in craniofacial surgery. However, its clinical use still suffers from the very large variety of different methods and parameters from which the surgeon may choose. This is true not only of the data acquisition but also for of documentation of the results. Furthermore, there is no standardisation of procedures according to classes of malformations. This paper presents a systematic investigation of these problems. It proposes a standardisation of craniofacial malformations and describes an optimisation of the procedure of 3D visualisation. The procedure described has become a standard tool for craniofacial surgery in our hospital.

Cleft Lip↗
PubMed1986

[3-dimensional display of computed tomographic studies of craniofacial anomalies].

Craniofacial anomalies are conventionally investigated by cephalometry using ordinary radiographs and by computed tomography. Both methods have the major disadvantage of trying to demonstrate a complex three-dimensional structure, such as the skull, in two dimensions and they therefore cannot display a true spatial image. We present the principle underlying a three-dimensional display derived from computer tomographic studies and discuss the clinical application in the diagnosis of craniofacial anomalies.

Adolescent↗
PubMedDate not supplied

A computerized three-dimensional atlas of the human skull and brain.

PURPOSE: To develop an anatomic atlas of the human head based on a volume model derived from MR and CT. METHODS: Every voxel of this model was labeled by a neuroanatomist concerning its membership to a structural and/or functional region. A computer program was written that, instead of displaying precomputed images, allows the user to choose and compose arbitrary views. RESULTS: The user can subtract parts and ask for annotations just by using the mouse. Conversely, one can compose images by choosing objects from the list of anatomical constituents which is displayed on the screen. A set of dissection tools allows a "look and feel" that comes near to a true dissection. Operations that are not possible in a real dissection, such as reassembly or filling cavities, can be performed. CONCLUSION: The authors have developed a computerized model that can be used for anatomy teaching and also as a reference for radiologists or surgeons. To replace classical atlases, the spatial resolution must be improved and speed must approach real time. Functional imaging data (position emission tomography and single photon emission CT) can be added to the system. The system is mobile and can be situated in classrooms, operating rooms, reading rooms, and libraries.

Brain↗
PubMedDate not supplied

A new method for representing the human anatomy.

In current practice, anatomical atlases are based on a collection of planar images presented in a book or, recently, stored on digital media. We present a new method for generating interactive true three-dimensional (3D) anatomical atlases based on a volume model derived from MRI and CT. The model has a two layer structure. The lower level is a volume model with a set of semantic attributes connected to each voxel. The semantic attributes are assigned by an anatomist using a volume editor. The upper level is a set of relations between these attributes. Interactive visualization tools such as multiple surface display, transparent rendering, and cutting are provided. It is shown that the combination of this data structure with advanced volume visualization tools provides the "look and feel" of real dissection. First tests show that the atlas system cannot only be used successfully for anatomy teaching, but also as a reference for radiologists or surgeons. As a replacement of classical atlases, however, the spatial resolution has still to be improved.

Anatomy↗