276 research outputs found

    Automatic Renal Segmentation in DCE-MRI using Convolutional Neural Networks

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    Kidney function evaluation using dynamic contrast-enhanced MRI (DCE-MRI) images could help in diagnosis and treatment of kidney diseases of children. Automatic segmentation of renal parenchyma is an important step in this process. In this paper, we propose a time and memory efficient fully automated segmentation method which achieves high segmentation accuracy with running time in the order of seconds in both normal kidneys and kidneys with hydronephrosis. The proposed method is based on a cascaded application of two 3D convolutional neural networks that employs spatial and temporal information at the same time in order to learn the tasks of localization and segmentation of kidneys, respectively. Segmentation performance is evaluated on both normal and abnormal kidneys with varying levels of hydronephrosis. We achieved a mean dice coefficient of 91.4 and 83.6 for normal and abnormal kidneys of pediatric patients, respectively

    3D Deep Learning for Anatomical Structure Segmentation in Multiple Imaging Modalities

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    Accurate, automated quantitative segmentation of anatomical structures in radiological scans, such as Magnetic Resonance Imaging (MRI) and Computer Tomography (CT), can produce significant biomarkers and can be integrated into computer-aided diagnosis (CADx) systems to support the in- terpretation of medical images from multi-protocol scanners. However, there are serious challenges towards developing robust automated segmentation techniques, including high variations in anatomical structure and size, varying image spatial resolutions resulting from different scanner protocols, and the presence of blurring artefacts. This paper presents a novel computing ap- proach for automated organ and muscle segmentation in medical images from multiple modalities by harnessing the advantages of deep learning techniques in a two-part process. (1) a 3D encoder-decoder, Rb-UNet, builds a localisation model and a 3D Tiramisu network generates a boundary-preserving segmentation model for each target structure; (2) the fully trained Rb-UNet predicts a 3D bounding box encapsulating the target structure of interest, after which the fully trained Tiramisu model performs segmentation to reveal organ or muscle boundaries for every protrusion and indentation. The proposed approach is evaluated on six different datasets, including MRI, Dynamic Contrast Enhanced (DCE) MRI and CT scans targeting the pancreas, liver, kidneys and iliopsoas muscles. We achieve quantitative measures of mean Dice similarity coefficient (DSC) that surpasses or are comparable with the state-of-the-art and demonstrate statistical stability. A qualitative evaluation performed by two independent experts in radiology and radiography verified the preservation of detailed organ and muscle boundaries

    Automatic Quantification of Epidermis Curvature in H&E Stained Microscopic Skin Image of Mice

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    Changes in the curvature of the epidermis layer is often associated with many skin disorders, such as ichthyoses and generic effects of ageing. Therefore, methods to quantify changes in the curvature are of a scientific and clinical interest. Manual methods to determine curvature are both laborious and intractable to large scale investigations. This paper proposes an automatic algorithm to quantify curvature of microscope images of H&E-stained murine skin. The algorithm can be divided into three key stages. First, skin layers segmentation based on colour deconvolution to separate the original image into three channels of different representations to facilitate segmenting the image into multiple layers, namely epidermis, dermis and subcutaneous layers. The algorithm then further segments the epidermis layer into cornified and basal sub-layers. Secondly, it quantifies the curvature of the epidermis layer by measuring the difference between the epidermis edge and a straight line (theoretical reference line) connecting the two far sides of the epidermis edge. Finally, the curvature measurements extracted from a large number of images of mutant mice are used to identify a list of genes responsible for changes in the epidermis curvature. A dataset of 5714 H&E microscopic images of mutant and wild type mice were used to evaluate the effectiveness of the algorithm

    Three-Year Follow-up of 2-Dose Versus 3-Dose HPV Vaccine

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    BACKGROUND AND OBJECTIVES: Human papillomavirus (HPV) antibody responses to the 9-valent abstract human papillomavirus (9vHPV) vaccine among girls and boys (aged 9–14 years) receiving 2- dose regimens (months 0, 6 or 0, 12) were noninferior to a 3-dose regimen (months 0, 2, 6) in young women (aged 16–26 years) 4 weeks after last vaccination in an international, randomized, open-label trial (NCT01984697). We assessed response durability through month 36. METHODS: Girls received 2 (months 0 and 6 [0, 6]: n = 301; months 0 and 12 [0, 12]: n = 151) or 3 doses (months 0,2, and 6 [0, 2, 6]: n = 301); boys received 2 doses ([0, 6]: n = 301; [0, 12]: n = 150); and young women received 3 doses ([0, 2, 6]: n = 314) of 9vHPV vaccine. Anti-HPV geometric mean titers (GMTs) were assessed by competitive Luminex immunoassay (cLIA) and immunoglobulin G-Luminex immunoassay (IgG-LIA) through month 36. RESULTS: Anti-HPV GMTs were highest 1 month after the last 9vHPV vaccine regimen dose, decreased sharply during the subsequent 12 months, and then decreased more slowly. GMTs 2 to 2.5 years after the last regimen dose in girls and boys given 2 doses were generally similar to or greater than GMTs in young women given 3 doses. Across HPV types, most boys and girls who received 2 doses (cLIA: 81%–100%; IgG-LIA: 91%–100%) and young women who received 3 doses (cLIA: 78%–98%; IgG-LIA: 91%–100%) remained seropositive 2 to 2.5 years after the last regimen dose. CONCLUSIONS: Antibody responses persisted through 2 to 2.5 years after the last dose of a 2-dose 9vHPV vaccine regimen in girls and boys. In girls and boys, antibody responses generated by 2 doses administered 6 to 12 months apart may be sufficient to induce high-level protective efficacy through at least 2 years after the second dose.Medicin

    Status of Pandemic Influenza Vaccination and Factors Affecting It in Pregnant Women in Kahramanmaras, an Eastern Mediterranean City of Turkey

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    BACKGROUND: Pregnant women are a target group for receipt of influenza vaccine because there appears to be an elevated mortality and morbidity rate associated with influenza virus infection in pregnant women. The goal of this study is to determine the factors affecting the decisions of pregnant women in Turkey to be vaccinated or not for 2009 H1N1 influenza. METHODOLOGY: We enrolled 314 of 522 (60.2%) pregnant women who attended to the antenatal clinics of the Medical Faculty of Kahramanmaras Sutcuimam University's Department of Gynecology and Obstetrics between December 23, 2009, and February 1, 2010. We developed a 48-question survey which was completed in a face-to-face interview at the clinic with each pregnant woman. PRINCIPAL FINDINGS: Of the 314 pregnant women, 27.4% were in the first trimester, 33.8% were in the second trimester, and 38.8% were in the third trimester. Twenty-eight pregnant women (8.9%) got vaccinated. Of all the women interviewed, 68.5% stated that they were comfortable with their decisions about the vaccine, 7.3% stated they were not comfortable, and 24.2% stated that they were hesitant about their decisions. The probability of receiving the 2009 H1N1 vaccine was 3.46 times higher among working women than housewives, 1.85 times higher among women who have a child than those who do not, and 1.29 times higher among women with a high-school education or higher than those with only a secondary-school education and below. Correct knowledge about the minimal risks associated with receipt of influenza vaccine were associated with a significant increase in the probability of receiving the 2009 H1N1 vaccine. CONCLUSIONS/SIGNIFICANCE: The number of pregnant women in the study group who received the 2009 H1N1 vaccine was very low (8.9%) and two-thirds of them stated that they were comfortable with their decisions concerning the vaccine. Our results may have implications for public health measures to increase the currently low vaccination rate among pregnant women. Further studies are required to confirm whether our findings generalize to other influenza seasons and other settings

    Live Cell Imaging of Bone Marrow Stromal Cells on Nano-pitted and Polished Titanium Surfaces: A Micro-Incubator in vitro Approach

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    Current orthopedic implants are not conducive for optimal integration of the biomaterial with newly-formed tissue (osseointegration) inside a patient’s body. In this study, medical-rade Ti-6Al-4V was used as a substrate due to its biocompatibility and ability to facilitate cellular adhesion and proliferation. Live cell imaging was conducted on bone marrow stromal cells, genetically modified to express the green fluorescent protein (GFP), from the 24-96 hours growth period, with the first 24 hours of growth being held inside a lab-scale incubator. Periodic images were recorded on nanopitted anodized and polished Ti-6Al-4V substrates to study how substratestiffness influences adhesion and proliferation. Collected images were analyzed for mitosis, adhesion, and filopodia-stretchability using ImageJ, an image processing program. Images were enhanced in order to perform cell counts at 24, 48, 72, and 96 hours of growth. Continuous recordings were produced to account for the number of mitosis occurrences and cellular migration on each of the substrates. Based on the conducted experiments, it appears that polished Ti-6Al-4V has a higher cell adherence than “nanopitted” anodized surface and an improved rate of proliferation which may be because the cells once adhered on the nano-pitted surface have less ability to detach in-order to undergo mitosis.https://engagedscholarship.csuohio.edu/u_poster_2014/1004/thumbnail.jp

    Burden of rotavirus gastroenteritis in the Middle Eastern and North African pediatric population

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    <p>Abstract</p> <p>Background</p> <p>Rotavirus gastroenteritis (RVGE) is the most common cause of severe childhood diarrhea worldwide. Objectives were to estimate the burden of RVGE among children less than five years old in the Middle East (Bahrain, Iran, Iraq, Israel, Jordan, Kuwait, Oman, Qatar, Saudi Arabia, Syria, UAE, Yemen), North Africa (Algeria, Egypt, Libya, Morocco, Tunisia) and Turkey.</p> <p>Methods</p> <p>A comprehensive literature search was conducted in major databases on the epidemiology and burden of rotavirus among children less than five years old between 1999 and 2009. Data from each country was extracted and compared.</p> <p>Results</p> <p>The search identified 43 studies. RVGE was identified in 16-61% of all cases of acute gastroenteritis, with a peak in the winter. RVGE-related hospitalization rates ranged from 14% to 45%, compared to 14%-28% for non-RVGE. Annually, RVGE caused up to 112 fatalities per 100,000 in certain countries in the region. Hospitalization costs ranged from 1.8to1.8 to 4.6 million annually, depending on the country. The most recent literature available showed that G1P[8] was the most prevalent genotype combination in 8 countries (range 23%-56%). G2P[4] was most prevalent in 4 countries (26%-48%). G9P[8] and G4P[8] were also frequently detected.</p> <p>Conclusions</p> <p>RVGE is a common disease associated with significant morbidity, mortality, and economic burden. Given the variety and diverse rotavirus types in the region, use of a vaccine with broad and consistent serotype coverage would be important to help decrease the burden of RVGE in the Middle East and North Africa.</p

    The value of ultrahigh resolution OCT in dermatology - delineating the dermo-epidermal junction, capillaries in the dermal papillae and vellus hairs

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    Optical coherence tomography (OCT) imaging of the skin is gaining recognition and is increasingly applied to dermatological research. A key dermatological parameter inferred from an OCT image is the epidermal (Ep) thickness as a thickened Ep can be an indicator of a skin disease. Agreement in the literature on the signal characters of Ep and the subjacent skin layer, the dermis (D), is evident. Ambiguities of the OCT signal interpretation in the literatue is however seen for the transition region between the Ep and D, which from histology is known as the dermo-epidermal junction (DEJ); a distinct junction comprised of the lower surface of a single cell layer in epidermis (the stratum basale) connected to an even thinner membrane (the basement membrane). The basement membrane is attached to the underlying dermis. In this work, we investigate the impact of an improved axial and lateral resolution on the applicability of OCT for imaging of the skin. To this goal, OCT images are compared produced by a commercial OCT system (Vivosight from Michaelson Diagnostics) and by an in-house built ultrahigh resolution (UHR-) OCT system for dermatology. In 11 healthy volunteers, we investigate the DEJ signal characteristics. We perform a detailed analysis of the dark (low) signal band clearly seen for UHR-OCT in the DEJ region where we, by using a transition function, find the signal transition of axial sub-resolution character, which can be directly attributed to the exact location of DEJ, both in normal (thin/hairy) and glabrous (thick) skin. To our knowledge no detailed delineating of the DEJ in the UHR-OCT image has previously been reported, despite many publications within this field. For selected healthy volunteers, we investigate the dermal papillae and the vellus hairs and identify distinct features that only UHR-OCT can resolve. Differences are seen in tracing hairs of diameter below 20 ?m, and in imaging the dermal papillae where, when utilising the UHR-OCT, capillary structures are identified in the hand palm, not previously reported in OCT studies and specifically for glabrous skin not reported in any other in vivo optical imaging studies
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