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Kimori Y.,National Institutes of Natural science
Journal of Clinical Bioinformatics | Year: 2011

Background: Medical image processing is essential in many fields of medical research and clinical practice because it greatly facilitates early and accurate detection and diagnosis of diseases. In particular, contrast enhancement is important for optimal image quality and visibility. This paper proposes a new image processing method for enhancing morphological features of masses and other abnormalities in medical images.Method: The proposed method involves two steps: (1) selective extraction of target features by mathematical morphology and (2) enhancement of the extracted features by two contrast modification techniques.Results: The goal of the proposed method is to enable enhancement of fine morphological features of a lesion region with high suppression of surrounding tissues. The effectiveness of the method was evaluated in quantitative terms of the contrast improvement ratio. The results clearly show that the method outperforms five conventional contrast enhancement methods. The effectiveness and usefulness of the proposed method were further demonstrated by application to three types of medical images: a mammographic image, a chest radiographic image, and a retinal image.Conclusion: The proposed method enables specific extraction and enhancement of mass lesions, which is essential for clinical diagnosis based on medical image analysis. Thus, the method can be expected to achieve automatic recognition of lesion location and quantitative analysis of legion morphology. © 2011 Kimori; licensee BioMed Central Ltd. Source

Koizumi A.,National Institutes of Natural science
Brain and Nerve | Year: 2015

Retinal ganglion cells are projecting neurons that send visual information from the retina to the brain. They generate different patterns of action potentials in response to different kinds of visual information. In the retinas of mammals such as mice or rabbits, there are functionally and morphologically diverse retinal ganglion cells. However, in the primate retina, midget and parasol cells are believed to be dominant, and show less diversity. In this study, we performed organotypic culture of retinas and acute gene transfection of GFPs by gene-gun. We found more diverse retinal ganglion cells, including directional selective ganglion cells, than we expected, even in the retinas of primates such as common marmosets. Further, we found a third pathway from the retina to the brain via the thalamus, in addition to the magnocellular and parvocellular pathways. Source

Kimori Y.,National Institutes of Natural science
Journal of Synchrotron Radiation | Year: 2013

Image processing methods significantly contribute to visualization of images captured by biomedical modalities (such as mammography, X-ray computed tomography, magnetic resonance imaging, and light and electron microscopy). Quantitative interpretation of the deluge of complicated biomedical images, however, poses many research challenges, one of which is to enhance structural features that are scarcely perceptible to the human eye. This study introduces a contrast enhancement approach based on a new type of mathematical morphology called rotational morphological processing. The proposed method is applied to medical images for the enhancement of structural features. The effectiveness of the method is evaluated quantitatively by the contrast improvement ratio (CIR). The CIR of the proposed method is 12.1, versus 4.7 and 0.1 for two conventional contrast enhancement methods, clearly indicating the high contrasting capability of the method. Source

Kimura T.,National Institutes of Natural science
Journal of Cutaneous Medicine and Surgery | Year: 2011

Background/Objective: In previous studies, the author noticed hypertrophic scar formation in hairless dogs. The purpose of this study was to evaluate both grossly and histopathologically hypertrophic scars in hairless dogs to explore any similarities with hypertrophic scars in humans and to introduce these dogs as an appropriate model for further investigation on hypertrophic scarring. Methods: Full-thickness wounds were made on the dorsolumbar skin of hairless dogs. Hypertrophic scarring was examined with three methods: clinical observations, dihydroxyphenylalanine (DOPA)-positive melanocytes, and skin histopathology. Results: Hairless dogs clinically developed the formation of hyperpigmented and hypertrophic scars that did not extend beyond the original wound margins. In hypertrophic scars of hairless dogs, the split epidermal sheet showed an increased number of DOPA-positive melanocytes with well-developed dendrites exhibiting activated melanocytes. There were very few DOPA-positive melanocytes in the repaired skin of haired dogs. Histopathologic examinations demonstrated that hypertrophic scars were fully reepithelialized and granulation tissue formation was accompanied by inflammatory cell infiltration. There was remodeling of thick collagens and fine elastic fibers in the course of hypertrophic scar formation. Conclusion: Experimental hypertrophic scars produced in hairless dogs have morphologic properties similar to those of human hypertrophic scars. © 2011 Canadian Dermatology Association. Source

National Institutes Of Natural Science | Date: 2015-06-01

A kinematic support structure of a groove-groove-groove type that reduces friction between a first base and a second base is provided. In the kinematic support structure, a first base comprises three grooves and a second base comprises three other grooves. Balls are all movable with respect to the first base and the second base. Two grooves corresponding in the two bases face each other across respective one of the balls.

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