Fig 12 - uploaded by Karl Heinz Höhne
Content may be subject to copyright.
Leonardo da Vinci's famous drawings of a skull in comparison to analogous aspects of a 2600-year-old Egyptian mummy generated from 200 computer tomograms
Source publication
Multi-slice images obtained from computer tomography and magnetic resonance imaging represent a 3D image volume. For its visualization we use a raycasting algorithm working on a gray-scale voxel data model. This model is extended by additional attributes such as membership to an organ or a second imaging modality (“generalized voxel model”). It is...
Similar publications
This paper presents a novel approach to support students to learn a comprehensive domain-specific terminology and to understand textual descriptions of complex-shaped objects. We implemented an experimen- tal system where learners can interactively explore textual descriptions and 3D visualizations. We propose a method for hierarchical content repr...
Citations
... Each extracted voxel expresses the attenuation coefficients, also known as "raw data". The raw data volumetric group is mathematically reconstructed, thereby obtaining a pixelated image [4,5]. All data obtained are strongly related between the size and number of voxels, the resolution of the image acquisition, and the volumetric reconstruction of the object in a pixelated and multiplanar image associated with the loss of the data; for a definitive evaluation, they are introduced as errors within the system [5]. ...
The primary purpose of this study was to determine the accuracy of micro-computed tomography (micro-CT) as a novel tool for the 3D analysis of bone density around dental implants in tibia rabbits. Six male New Zealand rabbits were used in our evaluation. One Copa SKY® (Bredent Medical GmbH & Co. K.G.) with a 3.5 mm diameter by 8.0 mm in length was placed within 12 tibia rabbits divided into two experimental groups: Group A (crestal placement) and Group B (sub-crestal placement). The animals were sacrificed at four weeks. Micro-CT evaluations showed a high amount of bone around all implants in the tibia rabbit bone. There was an increased formation of bone around the Copa SKY implants, mainly in the implants that were placed crestally. The most frequent density found in most implants was a medullary bone formation surrounding the implant; the density three (D3) was the most common type in all implants. The 3D model analysis revealed a mean bone volume (B.V.) of 31.24 ± 1.24% in crestal implants compared with the 43.12 ± 0.43% in sub-crestal implants. The mean actual contact implant to bone (B.I.C.) in the sub-crestal group was 51.76 ± 0.86%, compared to the 42.63 ± 0.75% in the crestal group. Compared to crestal implants, the Copa Sky implant placed sub-crestally allows for the formation of bone on top of the neck, thereby stimulating bone growth in tibia rabbits.
... Traditional 3D data models can be generalized into three types according to the different modeling ideas and methods which have been adopted: 3D vector data models (Bishr 1998), which are based on 3D topological relations; volumetric data models (Höhne et al. 1990); and mixed data models, which combine different models (Wu 2004). Moreover, managing data through symbolization or layering by using maps as templates tends to lead to overlays of 2D geometric representations (Perrin, Beauvais, and Puppo 2001) and crossed attributes of multiple factors. ...
The unified management and planning of national or provincial natural resources distributed both aboveground and underground have become increasingly important. Accurate depictions of natural resource elements and their interactions are key to achieving integrated and systematic management of natural resources. However, current spatiotemporal data models are based only on data descriptions, attribute records, and other model knowledge of a more general basis, without intuitively describing relationships between these elements and natural resources. This paper, therefore, proposes an integrated data-model-knowledge representation model to explicitly describe the time, space, and interaction of natural resource entities through an integrated knowledge graph. First, this study constructs a conceptual model using the aspects of semantics, scale, and data-model-knowledge, thereby explicitly describing the relationships of natural resources. Second, a logical model of natural resource representation is proposed, that is integrated with time, space, attributes, and relationships. Finally, taking the management of water resources as an example, this paper realizes the meticulous presentation of the levels of detail and rich semantic relations of natural resource entities. The findings of this study lay the foundation for a more efficient, precise, and lucid perception of the distribution laws and complicated interactional relationships of natural resources, both aboveground and underground.
... The visualization of voxel models has been intensively studied recently [4,5,6,7,8,9,10]. Multiple approaches has been proposed to improve the visualization performance. ...
... So great part of studies on voxel model visualization was carried out on medical data. Form the first works, researchers tried to find techniques for fast and realistic visualization [4,5]. The Far Voxels [6] method, that integrates visibility culling and out-of-core data management with a level-of-detail framework, allowed to improve the efficiency and generality of very large arbitrary surface models. ...
Single-image 3D scene reconstruction is required in multiple challenging tasks including mobile robotics, industrial monitoring and reconstruction of lost cultural heritage. While modern models demonstrate robust resolution of scene in real time with resolution up to 128 x 128 x 128 voxels, visualization of such detailed of a such detailed voxel model is challenging. A model with 128<sup>3</sup> voxels contains 2097152 simple cubes 16M vertices. It is unfeasible for modern hardware to perform visualization of such voxel models in real-time. Hence a voxel model simplification technique is required to demonstrate reconstruction results in real-time. In this paper, we propose a new algorithm for voxel model simplification using predefined camera views. The algorithm reduces a rigid-body voxel model to a shell voxel model. It keeps only the voxels that are visible from the required view. We demonstrate the effectiveness of the proposed algorithm using a case study with a mobile robot and a state-of-the-art SSZ single-photo 3D reconstruction neural network. We generated a real and a virtual scene with various objects including a statue. We use a mobile robot equipped with a single camera to collect real and synthetic data. We train the SSZ model using the collected data. We developed a dedicated visualization software that implements our algorithm. The comparison of the visualization performance for the full model and its reduced version demonstrates that our algorithm allows to increase the performance by 420 times.
... From each voxel, a data set of attenuation coefficients is extracted, being known as "raw data". This volumetric set of raw data is mathematically reconstructed (iterative reconstruction, filtered retro projection algorithms) to obtain a pixelated image [4,5]. ...
The aim of the study is to determine the existing correlation between high-resolution 3D imaging technique obtained through Micro Computed Tomography (mCT) and histological-histomorphometric images to determine in vivo bone osteogenic behavior of bioceramic scaffolds. A Ca-SiP scaffold ceramic doped and non-doped (control) with a natural demineralized bone matrix (DBM) were implanted in rabbit tibias for 1, 3, and 5 months. A progressive disorganization and disintegration of scaffolds and bone neoformation occurs, from the periphery to the center of the implants, without any differences between histomorphometric and radiological analysis. However, significant differences (p < 0.05) between DMB-doped and non-doped materials where only detected through mathematical analysis of mCT. In this way, average attenuation coefficient for DMB-doped decreased from 0.99 ± 0.23 Hounsfield Unit (HU) (3 months) to 0.86 ± 0.32 HU (5 months). Average values for non-doped decreased from 0.86 ± 0.25 HU (3 months) to 0.66 ± 0.33 HU. Combination of radiological analysis and mathematical mCT seems to provide an adequate in vivo analysis of bone-implanted biomaterials after surgery, obtaining similar results to the one provided by histomorphometric analysis. Mathematical analysis of Computed Tomography (CT) would allow the conducting of long-term duration in vivo studies, without the need for animal sacrifice, and the subsequent reduction in variability.
... In order to achieve our goal, we chose Direct Volume Rendering (DVR) technique for 3D visualization. It helps to generate an interactive 3D model which can be altered to show surfaces having different intensities [9]. DVR methods generate images of a 3D volumetric data set without explicitly extracting geometric surfaces from the data. ...
The goal of 3D visualization is to provide the user with an intuitive interface which enables him to explore the 3D data in an interactive manner. The aim of the exploration is to identify and analyze anomalies or to give proof of the non-anomaly of the visualized organic structures. For 3D Medical Data, Magnetic Resonance Images (MRI) has been used. To create the 3D model, we used the Direct Volume Rendering technique. In the input 3D data, we have $x, y$ and $z$ coordinates and an intensity value for each voxel. The 3D data is used by Volume Ray Casting to compute 2D projections from 3D volumetric data sets. In ray casting, a ray of light is made to pass through the volume data. The interaction of each voxel with this ray is used to assign RGB and alpha values for every voxel in the volume. As a result, we are able to generate the 3D model of the region of interest using the 3D data. The 3D model is interactive, thus enabling us to visualize the different layers of the 3D volume by adjusting the transfer function.
... Voxel representation is one of the most effective ways to describe the spatial occupation of any object in the 3D world [30]. Comparing with the traditional model that is constructed with triangular meshes, the voxel representation is able to give a more general view of the object's shape, without much information about the detailed features on the surface. ...
Structure is one of the most important properties of man-made objects, and it is beneficial for a number of applications. In this paper, we propose an effective method to recognize the 3D building models’ compositional structures, which represent the basic knowledge of human beings on the shape formation of the models in 3D space. To overcome the shortcomings of the traditional algorithms that are focused on the detailed geometric features of the surface meshes, volumetric analysis is employed here to study the compositional structures of the building models from inside. To describe the general shape of a building model in 3D space, the model is voxelized, and layered distance maps are generated to record its volumetric characteristics at different places. With reference to the value variation of the layered distance maps in the horizontal and vertical directions, different structural parts are identified in the voxel space, and the valid voxels are classified accordingly to obtain the voxel representation of each part. Based on the volume decomposition result, an extended topological graph (ETG) is then constructed for description of the compositional structure of the building model. As the spatial relationships between different parts are analyzed from inside and the whole process is implemented in the voxel space, the method is immune to the complicated and confusing features on the surfaces of the building models, with the scale of the structure recognition determined by the discretizing resolution of the voxel space. In the experiments, three typical building models are chosen for discussion of the effectiveness and efficiency of the proposed approach, and some example applications are shown to demonstrate its potential usage in different fields.
... This multi-sliced image data provides three-dimensional information, so that it can be visualized in 3D space and offers rich and precise visual information. The volume rendering method is a representative illustration of 3D visualization of CT volume data by a generalized voxel model [9]. However, CT scan data has its limitation in terms of diagnosis of the whole leg condition. ...
X-ray imaging is the conventional method for diagnosing the orthopedic condition of a patient. Computerized Tomography(CT) scanning is another diagnostic method that provides patient’s 3D anatomical information. However, both methods have limitations when diagnosing the whole leg; X-ray imaging does not provide 3D information, and normal CT scanning cannot be performed with a standing posture. Obtaining 3D data regarding the whole leg in a standing posture is clinically important because it enables 3D analysis in the weight bearing condition. Based on these clinical needs, a hardware-based bi-plane X-ray imaging system has been developed; it uses two orthogonal X-ray images. However, such methods have not been made available in general clinics because of the hight cost. Therefore, we proposed a widely adaptive method for 2D X-ray image and 3D CT scan data. By this method, it is possible to threedimensionally analyze the whole leg in standing posture. The optimal position that generates the most similar image is the captured X-ray image. The algorithm verifies the similarity using the performance of the proposed method by simulation-based experiments. Then, we analyzed the internal-external rotation angle of the femur using real patient data. Approximately 10.55 degrees of internal rotations were found relative to the defined anterior-posterior direction. In this paper, we present a useful registration method using the conventional X-ray image and 3D CT scan data to analyze the whole leg in the weight-bearing condition.
... Three-dimensional image reconstruction has more extensive and mature application in medical image processing, mechanical manufacturing, computer animation, film and television design and many other fields [1] [2] [3]. In the meteorological field, owing to the weather objects in the entire detection space are discrete, irregular and uneven distributed, most of the visualization products are confined into the two-dimensional structure, as shown in Figure 1, the images reconstructed from the radar data with two elevation angles in Kunming Radar Station at 18:23 on July 18, 2013. ...
3D image reconstruction for weather radar data can not only help the wea-therman to improve the forecast efficiency and accuracy, but also help people to understand the weather conditions easily and quickly. Marching Cubes (MC) algorithm in the surface rendering has more excellent applicability in 3D reconstruction for the slice images; it may shorten the time to find and calculate the isosurface from raw volume data, reflect the shape structure more accurately. In this paper, we discuss a method to reconstruct the 3D weather cloud image by using the proposed Cube Weighting Interpolation (CWI) and MC algorithm. Firstly, we detail the steps of CWI, apply it to project the raw radar data into the cubes and obtain the equally spaced cloud slice images, then employ MC algorithm to draw the isosurface. Some experiments show that our method has a good effect and simple operation, which may provide an intuitive and effective reference for realizing the 3D surface reconstruction and meteorological image stereo visualization.
... Many researchers have put their efforts on the heterogeneous 3D printing especially for the mathematically modeling of heterogeneous bio-model. The methods for the heterogeneous 3D model construction include modeling with voxel [12][13][14][15] and representing with traditional boundary. The advantages of the voxel modeling method are that the unit density is controllable and the local geometrical features are adaptive, and it can accurately express the material distribution characteristic of the 3D heterogeneous material model, especially for the three-dimensional entity with inhomogeneous material distribution. ...
A kind of digitally designing and manufacturing system for the gradient heterogeneous 3D printing was designed. The molar model of PLY format was composed based on the CT images, and a novel method for the gradient heterogeneous material model designing based on the material distribution control function and the sliced edge rings was proposed. The point color slicing algorithm based on the topological structure was achieved. Based on the system, a gradient heterogeneous dental model was prepared. The algorithm used for constructing and slicing of the molar model could store the geometry and material information effectively, and maintain the compatibility for the heterogeneous 3D printer. The system supplied a fast and integrating method for the heterogeneous 3D Bio-model printing.
... Selection of an appropriate approach to a segmentation problem can therefore be a difficult dilemma. Hohne et al. [5] used ray casting algorithm working on a gray scale voxel data. Shen et al. [6] presented a deformable model for automatically segmenting brain structures from volumetric MR images and obtaining point correspondences using geometric and statistical information in a hierarchical scheme. ...
Most of the current radiation therapy planning systems, which are based on pre-treatment Computer Tomography (CT) images, assume that the tumor geometry does not change during the course of treatment. However, tumor geometry is shown to be changing over time. We propose a methodology to monitor and predict daily size changes of head and neck cancer tumors during the entire radiation therapy period. Using collected patients' CT scan data, MATLAB routines are developed to quantify the progressive geometric changes occurring in patients during radiation therapy. Regression analysis is implemented to develop predictive models for tumor size changes through entire period. The generated models are validated using leave-one-out cross validation. The proposed method will increase the accuracy of therapy and improve patient's safety and quality of life by reducing the number of harmful unnecessary CT scans.
