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Rikio Kato

Publications and source records attributed to Rikio Kato.

2 recordsLinked to original sources

An abnormal accumulation of fluorine-18-FDG PET in cytomegalovirus enteritis--a case report.

The source of a fever of unknown origin (FUO) and watery diarrhea in a 63-yr-old female with a history of disturbance of consciousness due to moyamoya disease was examined. Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET), colonoscopy, blood analysis, and determination of cytomegalovirus (CMV) antigenemia were performed. FDG was found to be accumulated in the wall of a dilated colon, and extended from the transverse to sigmoid colon. Colonoscopy revealed edematous, inflammatory, and punched out lesions in accordance with the areas of abnormal FDG uptake. A biopsy specimen showed the antibody of CMV in the colonic mucosa, and CMV antigenemia was detected by an immunohistochemical assay using a monoclonal antibody for CMV pp65 antigen. From these findings, we strongly suspected CMV enteritis.

Cytomegalovirus↗

Development of a practical image-based scatter correction method for brain perfusion SPECT: comparison with the TEW method.

PURPOSE: An image-based scatter correction (IBSC) method was developed to convert scatter-uncorrected into scatter-corrected SPECT images. The purpose of this study was to validate this method by means of phantom simulations and human studies with 99mTc-labeled tracers, based on comparison with the conventional triple energy window (TEW) method. METHODS: The IBSC method corrects scatter on the reconstructed image I(mub)AC with Chang's attenuation correction factor. The scatter component image is estimated by convolving I(mub)AC with a scatter function followed by multiplication with an image-based scatter fraction function. The IBSC method was evaluated with Monte Carlo simulations and 99mTc-ethyl cysteinate dimer SPECT human brain perfusion studies obtained from five volunteers. The image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were compared. RESULTS: Using data obtained from the simulations, the image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were found to be nearly identical for both gray and white matter. In human brain images, no significant differences in image contrast were observed between the IBSC and TEW methods. CONCLUSION: The IBSC method is a simple scatter correction technique feasible for use in clinical routine.

Algorithms↗