The Experts below are selected from a list of 37404 Experts worldwide ranked by ideXlab platform

Valerii V Tuchin - One of the best experts on this subject based on the ideXlab platform.

  • Visualisation of distribution of gold nanoparticles in Liver tissues ex vivo and in vitro using the method of optical coherence tomography
    Quantum Electronics, 2012
    Co-Authors: Elina A. Genina, Georgy S. Terentyuk, Boris N. Khlebtsov, Alexey N. Bashkatov, Valerii V Tuchin
    Abstract:

    The possibility of visualising the distribution of gold nanoparticles in Liver by means of the method of optical coherence tomography is studied experimentally in model samples of beef Liver in vitro and rat Liver ex vivo. In the experiments we used the gold nanoparticles in the form of nanocages with resonance absorption in the near-IR spectral region. In the model studies the suspension of nanoparticles was applied to the surface of the sample, which then was treated with ultrasound. In the ex vivo studies the suspension of nanoparticles was injected to the laboratory rats intravenously. The image contrast and the optical depth of detection of blood vessels and Liver Structure components are calculated, as well as the depth of Liver optical probing before and after the injection of nanoparticles. It was shown that the administration of the nanoparticle increases significantly the imaging contrast of Liver blood vessels owing to the localisation of the nanoparticles therein.

Kyung-sik Seo - One of the best experts on this subject based on the ideXlab platform.

  • ICCSA (4) - Automatic boundary tumor segmentation of a Liver
    Computational Science and Its Applications – ICCSA 2005, 2005
    Co-Authors: Kyung-sik Seo, Tae Woong Chung
    Abstract:

    This paper proposes automatic boundary tumor segmentation for the computer aided Liver diagnosis system. As pre-processing, the Liver Structure is first segmented using histogram transformation, multi-modal threshold, C-class maximum a posteriori decision, and binary morphological filtering. After binary transformation of the Liver Structure, the image based bounding box is created and convex deficiencies are segmented. Large convex deficiencies are selected by pixel area estimation and selected deficiencies are transformed to gray-level deficiencies. The boundary tumor is selected by estimating the variance of deficiencies. In order to test the proposed algorithm, 225 slices from nine patients were selected. Experimental results show that the proposed algorithm is very useful for diagnosis of the abnormal Liver with the boundary tumor.

  • Point-based Liver and hepatic tumor segmentation and estimation
    2004
    Co-Authors: Kyung-sik Seo, Lonnie C. Ludeman
    Abstract:

    Liver cancer is the fifth most common cancer in the world. Liver cancer is more serious in areas of western and central Africa and eastern and southeastern Asia. The average incidence of Liver cancer in these areas is 20 per 100,000, and Liver cancer is the third highest death cause from cancer. Roughly 20,000 new cases of Liver cancer are diagnosed every year in the USA. If a very small lump tumor is found by early detection, treatment and curing may be easy, and human life can be prolonged. In this dissertation, point-based Liver and hepatic tumor segmentation and estimation are presented in contrast enhanced (CE)-computed tomography (CT) images. Without having a reference image and training data, fully automatic segmentation of the Liver Structure and tumors using a reference point based on the spine is processed. Segmentation of the Liver Structure and tumors is performed regardless of pixel variation of CE-CT images involved by contrast agent. After obtaining CE-CT images, pre-processing such as histogram transformation and adaptive multi-modal threshold is performed. In order to process fully automatic segmentation for the Liver Structure and tumors, a reference point from the spine is defined. Liver segmentation using C-class maximum a posteriori decision and binary morphological filtering is processed. Partial histogram threshold algorithms are proposed in order to perform better Liver segmentation. Finally, an inner small tumor is found, and large inner tumors using two statistical optimal thresholds are segmented. Boundary tumors of the Liver are extracted by the bounding box and convex hull. Segmented tumors are evaluated by four basic possibilities, such as true negative, false positive, false negative, and true positive. As the evaluation measure, sensitivity, specificity, and accuracy are calculated.

  • Automatic Liver Segmentation of a Contrast Enhanced CT Image Using a Partial Histogram Threshold Algorithm
    2004
    Co-Authors: Kyung-sik Seo, Seung-jin Park, Jong An Park
    Abstract:

    Pixel values of contrast enhanced computed tomography (CE-CT) images are randomly changed. Also, the middle Liver part has a problem to segregate the Liver Structure because of similar gray-level values of a pancreas in the abdomen. In this paper, an automatic Liver segmentation method using a partial histogram threshold (PHT) algorithm is proposed for overcoming randomness of CE-CT images and removing the pancreas. After histogram transformation, adaptive multi-modal threshold is used to find the range of gray-level values of the Liver Structure. Also, the PHT algorithm is performed for removing the pancreas. Then, morphological filtering is processed for removing of unnecessary objects and smoothing of the boundary. Four CE-CT slices of eight patients were selected to evaluate the proposed method. As the average of normalized average area of the automatic segmented method II (ASM II) using the PHT and manual segmented method (MSM) are 0.1671 and 0.1711, these two method shows very small differences. Also, the average area error rate between the ASM II and MSM is 6.8339 ％. From the results of experiments, the proposed method has similar performance as the MSM by medical Doctor.

Douglas L Schmucker - One of the best experts on this subject based on the ideXlab platform.

  • age related changes in Liver Structure and function implications for disease
    Experimental Gerontology, 2005
    Co-Authors: Douglas L Schmucker
    Abstract:

    The geriatric populations of many countries are growing rapidly and they present major problems to healthcare infraStructures from both medical and economic perspectives. The elderly are predisposed to a variety of diseases, which contribute to a marked increase in morbidity in this subpopulation. The incidence of Liver disease increases in the elderly, but the cellular and subcellular perturbations that underlie this suspected predisposition to pathology remain unresolved. Several age-related changes have been documented, including (a) a decline in Liver volume, (b) an increase in the hepatic dense body compartment (lipofuscin), (c) moderate declines in the Phase I metabolism of certain drugs, (d) shifts in the expression of a variety of proteins and (e) diminished hepatobiliary functions. Other more subtle changes (e.g., muted responses to oxidative stress, reduced expression of growth regulatory genes, diminished rates of DNA repair, telomere shortening) may contribute to reduced hepatic regenerative capacity, shorter post-Liver transplant survival and increased susceptibility to certain Liver diseases in the elderly.

  • Age-related changes in Liver Structure and function: Implications for disease ?
    Experimental gerontology, 2005
    Co-Authors: Douglas L Schmucker
    Abstract:

    The geriatric populations of many countries are growing rapidly and they present major problems to healthcare infraStructures from both medical and economic perspectives. The elderly are predisposed to a variety of diseases, which contribute to a marked increase in morbidity in this subpopulation. The incidence of Liver disease increases in the elderly, but the cellular and subcellular perturbations that underlie this suspected predisposition to pathology remain unresolved. Several age-related changes have been documented, including (a) a decline in Liver volume, (b) an increase in the hepatic dense body compartment (lipofuscin), (c) moderate declines in the Phase I metabolism of certain drugs, (d) shifts in the expression of a variety of proteins and (e) diminished hepatobiliary functions. Other more subtle changes (e.g., muted responses to oxidative stress, reduced expression of growth regulatory genes, diminished rates of DNA repair, telomere shortening) may contribute to reduced hepatic regenerative capacity, shorter post-Liver transplant survival and increased susceptibility to certain Liver diseases in the elderly.

Roderick H.j. Houwen - One of the best experts on this subject based on the ideXlab platform.

  • benign recurrent intrahepatic cholestasis progressing to progressive familial intrahepatic cholestasis low ggt cholestasis is a clinical continuum
    Journal of Hepatology, 2002
    Co-Authors: Nancy A M Van Ooteghem, Leo W. J. Klomp, Gerard P Van Bergehenegouwen, Roderick H.j. Houwen
    Abstract:

    Benign recurrent intrahepatic cholestasis (BRIC) is an autosomal recessive Liver disease, characterised by intermittent attacks of cholestasis, which can start at any age and last for several weeks to months. Characteristically serum GGT activity is low and normal Liver Structure is preserved. Progressive familial intrahepatic cholestasis (PFIC) is another Liver disease, characterised by severe cholestasis, starting almost invariably before 6 months of age. All patients progress to cirrhosis, Liver failure and death, unless a Liver transplantation is performed. We now identified four patients who presented in childhood with recurrent attacks of cholestasis, while in the course of the disease the cholestasis gradually became permanent. Although Liver biopsies performed in the early stages of the disease showed normal Liver architecture, late stage biopsies revealed evident fibrosis with porto-portal septa formation. In conclusion, the disease of these patients started with the clinical and histopathological characteristics of BRIC but progressed to PFIC.

Isamu Koyama - One of the best experts on this subject based on the ideXlab platform.

  • Effect of Continuous Application of Shear Stress on Liver Tissue: Continuous Application of Appropriate Shear Stress Has Advantage in Protection of Liver Tissue
    Transplantation proceedings, 2005
    Co-Authors: Takahiro Torii, Mitsuo Miyazawa, Isamu Koyama
    Abstract:

    Rapid blood flow changes occur in the Liver following a massive resection or in the grafted Liver following transplantation, under which shear stress (SS) change induced by the flow change may determine the postoperative results. We observed changes in Liver tissue Structure and Liver-specific function, and consequently assessed SS effect. The cultured Liver tissue exposed to continuous application of moderate SS was shown to express and maintain a long-term Liver-specific function. There was also evidence showing that destruction of the Liver Structure was inhibited. However, the cultured Liver tissue not exposed to SS or exposed to high SS was shown to lose Liver-specific function soon after expression. The Liver Structure was destroyed in the early stage of incubation. These results suggested that continuous application of appropriate SS has advantages over other types of stresses to protect Liver tissue.