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Computed tomography has played a key role in bone structure imaging for over two decades. However, when a metal implant present in the sample, the reconstructions are seriously distorted by artefacts, and no method has successfully met the clinical demands. This paper presents a new method for partial reconstruction in computed tomography. The metal implant is reconstructed separately and the correspondence...
In order to optimize the position of oral implants and make the best possible use of the available bone volume in the oral implant therapy, a computer-aided oral implantology system including the framework, modeling, preoperative 3D planning, registration method, optical tracking systems and real-time navigation is introduced in this study. With the support of this system, the precision achieved in...
While focusing at accurate 3D joint kinematics, this paper explores the problem of how to perform a robust rigid registration for a sequence of object surfaces observed using standard 3D medical imaging techniques. Each object instance is assumed to give access to a polyhedral encoding of its boundary. We consider the case where object instances are noised with significant truncations and segmentation...
In order to study the biomechanical mechanism properties of intervertebral disc herniation, combining the CT and MRI data-based anatomical structure of spine. A three-dimensional geometric model of the lumber disk was constructed. Based on the geometric model, a three-dimensional finite element modeling (FEM) for biomechanical analysis has been created. The FEM will represents a promising tool in...
An algorithm to determine the human brain (gray matter (GM) and white matter (WM)) from computed tomography (CT) head volumes with large slice thickness is proposed based on thresholding and brain mask propagation. Firstly, a 2D reference image is chosen to represent the intensity characteristics of the original 3D data set. Secondly, the region of interest of the reference image is determined as...
Accurate segmentation is critical in many advanced imaging applications such as volume determination, radiation therapy, 3D rendering, and surgery planning. However, due to the complex anatomical structure of tissue and organs, as well as artifacts caused by patient motion, beam hardening, and partial volume effect in CT image, the boundaries between different regions are smeared. In addition, the...
This paper describes a surgical navigation system for anterior cruciate ligament (ACL) reconstruction using an autostereoscopic image overlay technique. We superimpose a real three-dimensional (3-D) image onto the patient for image-guided therapy. The images are created by employing an animated visualization of integral videography (IV). IV records and reproduces 3-D images using a micro convex lens...
Traditional techniques for analyzing tortuous anatomical structures (e.g. arteries, colon, spine) in the coordinate system of the 3D image generally do not provide sufficient or qualitative enough diagnostic information, because planar cross-sections do not follow curved paths along the structures. To overcome this shortcoming, images in the coordinate system of the structure must be created. We propose...
Though interactive direct volume rendering produces meaningful images with high quality, it cannot display separate inner ear labyrinth or cochlea only by adjusting imaging parameters to suppress the surrounding structures. Novel semi-automatic segmentation methods were presented to extract the cochlea and inner ear from spiral CT images. The cochlea was separated from the medical image volume by...
Although there are many medical image processing and virtual surgery systems that provide rather consummate 3D-visualization and data manipulation techniques, few of them can export the volume data for engineering analyze. The thesis presents an interface implementing IGES (initial graphics exchange specification). Volume data such as bones, skins and other tissues can be exported as IGES files to...
The anatomical human structure recognition is very important and necessary during the development of computer-aided diagnosis (CAD) system. In this paper, we propose an image processing scheme that can recognize the general structure of human torso by identifying the human torso region from CT images automatically and separating it into 7 parts: skin, subcutaneous fat, muscle, bone, diaphragm, thoracic...
Computer-assisted surgery is the process of using medical images, such as CT scans, X-ray fluoroscopy, or 3D ultrasound, to improve patient care. A typical surgical procedure begins by acquiring and processing a CT scan with specially developed image-analysis software. A surgeon then performs a "virtual surgery" on the patient to develop a preoperative plan. In the operating room the medical...
This paper addresses the problem of surface reconstruction from partial data consisting of digitized landmarks and surface points that are obtained intra-operatively. The surface is derived by deforming a template so that the reconstructed surface matches the digitized points. Two techniques are employed to address such an ill-posed problem. First, a patient-specific template is used, which is computed...
Trabecular bone structure and bone density contribute to the strength of bone and are important in the study of osteoporosis. Wavelets are a powerful tool to characterize and quantify texture in an image. In this study the thickness of trabecular bone was analyzed in 8 cylindrical cores of the vertebral spine. Images were obtained from 3 Tesla (T) magnetic resonance imaging (MRI) and micro-computed...
A three-dimensional accurate foot model including bones, cartilages, ligaments and tendons was developed from 3D reconstruction of CT images. The model was used to analyze stress-strain of the joint between the first metatarsal and the medial cuneiform and to study the relationship of the range of motion of the first ray and hallux valgus
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