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Biomedical subjects

J Toriwaki

Publications and source records attributed to J Toriwaki.

18 recordsLinked to original sources

Virtualized angioscopy of the thoracic aorta in a rabbit model of atherosclerosis.

The purpose of this study was to apply virtual reality technology to spiral computed tomographic (CT) angiogram images in a rabbit model of atherosclerosis and to correlate the images with histopathologic evaluation of the aorta. Image data were transferred to the virtual endoscope system in a graphics workstation. "Virtualized angioscopy" includes an interactive graphic user interface, which controls the viewpoint, the direction of the observation, and rendering and navigation functions. The virtual angioscopy system demonstrated irregularities of the luminal surface of the ascending aorta and a smooth luminal surface in the descending aorta. These observations were correlated with histopathologic findings. The results of this study indicate that the potential and real benefits of virtualized angioscopy far outweigh several technical limitations.

Angioscopy

[A hip joint surgical planning system using 3-D images].

This paper describes a hip joint surgical simulation system using a three-dimensional image (X-ray CT images). We developed this system in cooperation with surgeons, and we have already applied it to several clinical examples. According to a surgeon who used our system for actual surgical plannings, most of the hip joint surgeries operated at the present time can be simulated. Our system has useful functions in order to plan surgeries such as interference check in movement of a bone and display of the attached surface of bone. We show an actual surgical planning process performed by the surgeon with our system.

Computer Simulation

[Radiography].

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Humans

[Image processing].

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Electronic Data Processing

Automatic segmentation of head MRI images by knowledge guided thresholding.

In this paper we present a procedure which automatically extracts soft-tissue from multi-sliced head MRI images, and then displays three-dimensional shapes of the extracted soft-tissues. We use an iterative thresholding algorithm for segmentation in which an optimum threshold value is decided based on a goodness measure we proposed. This procedure can be used in a preliminary diagnosis in brain surgery without much effort of users, because of whole procedure including threshold selection and segmentation is performed automatically for rendering a three-dimensional image of soft-tissue's surface on a graphic terminal.

Adipose Tissue

Computer-aided interactive surgical simulation for craniofacial anomalies based on 3-D surface reconstruction CT images.

We developed a computer-aided interactive surgical simulation system for craniofacial anomalies based on three-dimensional (3-D) surface reconstruction CT imaging. This system has four functions: 1) 3-D surface reconstruction display with an accelerated projection method; 2) Surgical simulation to cut, move, rotate, and reverse bone-blocks over the reference 3-D image on the CRT screen; 3) 3-D display of the simulated image in arbitrary views; and 4) Prediction of postoperative skin surface features displayed as 3-D images in arbitrary views. Retrospective surgical simulation has been performed on three patients who underwent the fronto-orbital advancement procedures for brachycephaly and two who underwent the reconstructive procedure for scaphocephaly. The predicted configurations of the cranium and skin surface were well simulated when compared to the postoperative images in 3-D arbitrary views. In practical use, this software might be used for an on-line system connected to a large scale general-purpose computer.

Computer Graphics