Computer-aided diagnosis (CAD) is a diagnosis made by a physician who takes into account the results of quantitative analysis of medical images by computer. The CAD systems, especially called as computer-aided detection (CAD) systems, are now commercially available at least in the two diagnostic fields, i.e., breast cancer diagnosis by mammograms (automated detections of masses and clustered microcalcifications) and thoracic cancer diagnosis by chest radiograms and X-ray CT images (automated nodule detection). Recent studies have indicated promising results in that the computer output can improve the performance of radiologists in detecting lesions on radiographic images. The CAD will make rapid progress to different modalities and various diagnostic regions. In this article, the latest information on mammography CAD for breast image diagnosis is mainly provided with a brief description on ultrasound CAD.

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This paper briefly overviews the virtual endoscopy system and its application to diagnosis of the bronchus. Ten years have passed from the initial reports of virtual endoscopy systems. Nowadays, virtual endoscopy systems are widely used in the medical field as one of the visualization methods of three-dimensional medical images. This paper briefly explains basic techniques for generating virtual endoscopic views and implementation of the virtual endoscopy system. Also, some of applications to diagnosis of the bronchus are shown. We introduce the VES that displays anatomical names of bronchial branches on virtual bronchoscopic views. Bronchoscope navigation system is explained with tracking results of the real bronchoscope. Clinical study, which employs VES as a guidance tool of real bronchoscopy, is also introduces. We show combination of VES and virtual reality devices as a technique that emphasizes immersion feelings. VES also can be used as a teaching tool of medical students. Several functions for education are presented. Virtual endoscopy inside the pulmonary alveolus is demonstrated as the future level of virtual endoscopy

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With the introduction of multislice CT technology, new-generation alternative techniques for colorectal cancer imaging have been reported. These new imaging techniques, such as 3 D-CT, virtual colonoscopy, and virtually stretched image of the colon can be used by commercially available image workstations. Three-dimensional CT image gives us easy understanding how running the colon in the abdomen and the status or the location of cancer viscerally. Virtual colonoscopy shows the endoscopic view of the colon that is almost same as the view of colonoscopy. Recent application provides more flexible navigation system. “One click” can setup the trace route of the entire colon automatically, which combines the views of the cross-sectional images give more accurate information. Virtually stretched image of the colon likes the features of surgically resected specimen. As for this method, the observation of the entire colon is speedy and easily. However interpretation of these images is time-consuming, if we apply these methods for screening of the colon. New developments such as tools of computer-aided diagnosis will be introduced near feature. At that time, current standard techniques for colorectal cancer screening including radiographic imaging (barium enema) and colonoscopy, may replace these new-generation techniques.

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A training system for central venous injection is proposed. Central venous injection is a part of central venous catheter (CVC) placement. In the CVC placement first, the needle is inserted to the vein. Then catheter is passed along the needle. During the insertion of the needle, pneumothorax and damages to the vein should be avoided. In proposed training system, we can virtually perform the injection to the human which is visually and haptically rendered. The 3D structure of human body was reconstructed from CT images using surface rendering technique. Using stereoscopic glasses, the life sized virtual human is displayed. Calculation method of haptic texure which defines the hardness at human surface is proposed. We realized virtual palpation by using haptic texture. Measurement method of the parameter used in haptic texture model is also proposed. PHANToM haptic device is used for recording and reproducing the sense of touch to cancel out the error each other. We also applied the calculation method of haptic texture to medical training system for the lumber puncture.

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This paper describes a surgical simulator based on shared virtual reality technique. The simulator enables users to share virtual surgical fields over information network and to perform collaborative virtual surgery within the shared virtual space. Thus, the simulator lets any person to experience surgical simulation under the guidance of expert doctors. Consequently, the simulator may promote social understandings for clinical and surgical works. The simulator evaluated under distributed surgical training for high school students and the results indicate that an experience under the developed simulator promotes interests about the clinical and surgical works.

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