We attempted to obtain the three dimensional (3D) helical CT scans (3D-CT) of digestive tract by using the air as a contrast medium, and we assessed the usefulness of 3D-CT in the diagnosis of gastric and colorectal cancer. Gastrointestinal 3D-CT has several kinds of visualizing methods depending on the threshold and transparency setting of CT values. In abdominal study, gastrointestinal 3D-CT images enabled the visualization of cancer and its adjacent structures in versatile directions, including a view similar to endoscopic observation, the whole aspect of cancer, proximal aspect of narrowing and obstruction by tumor and also could get the information about invasive depth of the cancer. The characteristics of our method are that we can easily make an examination in a short time and with little dependence on expert technique. Also patients have little discomfort compared to that experienced during endoscopy and barium X-ray study. Important features are as follows; 1)long calculation time,2) insufficient air insufflation,3)fecal and indigested material in the patient's digestive tract,4) whole abdominal scan,5) spatial resolution. In the near future, a multi-slice CT scanner system will have come into wide use for gastrointestinal 3D-CT. In the present report we have explain the 3D-reconstruction method, clinical exam method and have also deal with the advantages and various problems in gastrointestinal 3D-CT examination as well as countermeasures.

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Imaging Diagnosis of bone and soft tissue tumor has shown a great improvement in these 20 years. Especially the appearence of MRI was epochmaking. However, because of the expensive cost, all patients complaining with mass should not be indicated to MRI. Screening of the case which really require MRI is important. In outpatient department, simple and economic examination is important to select the patient. As for bone tumor, plain XP is useful tool in screening. However, plain XP has only limited value in the diagnosis of soft tissue tumor. Computad radiography and ultrasonography were useful tools to diagnose hemangioma, ganglion and lipoma which are common benign tumor. And schwannoma was also diagnosed by the characteristic findings which were referred pain, intermuscular mass demonstrated by computed radiography and biphasic pattern on ultrasonography. If soft tissue tumor did not show above findings, needle biopsy was required and cytological findings showed that the tumor was malignant or benign. According to these findings the indication of CT scan and/or MRI should be decided.

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Abnormal interventricular septal wall motion has been observed in various heart diseases. To assess the regional contractility of interventricular septum precisely, DANTE tagging cine MRI of septal slices parallel to the vertical long axis of left ventricle were acquired in 6normal volunteers and in 12 patients with a variety of heart diseases. DANTE tags were generated at end diastole with a 8 mm grid with about 60 intersection points on septal slice. Quadrangle area as a basic unit was calculated at end systole (S_ES) and end diastole (S_ES). Percent area contraction (PAC) was derived from the following formula: PAC= [(S_ES-S_ES)/S_ED]×100%. In addition, a quantitative map of the PAC was made to estimate regional contractility easily by visual inspection. The PAC was 29.4±1.3% in normal volunteers and the map of the PAC showed a homogeneous pattern. In patient with anteroseptal myocardial infarction reduced PAC units were localized at anterior site of interventricular septum, and in patients with inferior myocardial infarction, decreased PAC units were observed in inferoposterior site of interventricular septum. In a patient with dilated cardiomyopathy, the map demonstrated a diffused focal distribution of decreased PAC units. In conclusion, the PAC derived from DANTE-tagging cine MRI is a very useful index to evaluate regional contractility of interventricular septum, and the map of PAC can reflect regional abnormal contractility in accordance with clinical settings.

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For the purpose of constructing a diagnosis support system in fundus images employing in mass screening, two new schemes for extracting blood vessels and for detecting their intersections were proposed. An examination was performed with 24 fundus images from 12screenees by using a double-ring-shape filter and a band-shape filter. As a result,78% of blood vessels were extracted correctly and 83% of the intersections were detected. It was concluded that our experimental methods were useful to develop a system that could be tested in clinical situations.

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In this paper, we proposed a novel method, which employed a genetic-algorithm (GA)based hierarchical neural network in order to establish a general-purpose region segmentation technique for gray scale images. We also applied the method to medical images. In the present study we used 6 texture features for segmentation. These features were basically obtained from a gray-level cooccurrence matrix. During the training phase, three GA operators, namely, selection, cross and mutation were applied. The training was repeated until the recognition rate for the boundary of two different regions reached 90%. Our preliminary results found that the proposed method is effective not only in the segmentation of conventional color images but also in x-ray CT images and MR images. Moreover, we noted that the use of different image features could improve the performance of image segmentation for medical images.

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Radiographic images using the screen-film system have various noise called quantum mottle, screen structure mottle and film granularity. It is well known that these noise affect the detection of the signal in the image. We have presented a random-dot model with triply Poisson Process(RDM-TPP) to explain statistical properties of radiographic image noise. In this study, we apply RDM-TPP to theoretical analysis of characteristics of screen speed and film granularity. By numerical calculations of Wiener Spectrum, we show that parameters of RDM-TPP can correspond to characteristics of screen speed and Wiener Spectrum of film granularity can be obtained by use of RDM-TPP. The theoretical results of numerical calculations show that there are some similarities of the shape between the practical Wiener spectrum and the theoretical Wiener spectrum.

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