128 research outputs found

    Automatic delineation of malignancy in histopathological head and neck slides

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    <p>Abstract</p> <p>Background</p> <p>Histopathology, which is one of the most important routines of all laboratory procedures used in pathology, is decisive for the diagnosis of cancer. Experienced histopathologists review the histological slides acquired from biopsy specimen in order to outline malignant areas. Recently, improvements in imaging technologies in terms of histological image analysis led to the discovery of virtual histological slides. In this technique, a computerized microscope scans a glass slide and generates virtual slides at a resolution of 0.25 ÎŒm/pixel. As the recognition of intrinsic cancer areas is time consuming and error prone, in this study we develop a novel method to tackle automatic squamous cell carcinoma of the head and neck detection problem in high-resolution, wholly-scanned histopathological slides.</p> <p>Results</p> <p>A density-based clustering algorithm improved for this study plays a key role in the determination of the corrupted cell nuclei. Using the Support Vector Machines (SVMs) Classifier, experimental results on seven head and neck slides show that the proposed algorithm performs well, obtaining an average of 96% classification accuracy.</p> <p>Conclusion</p> <p>Recent advances in imaging technology enable us to investigate cancer tissue at cellular level. In this study we focus on wholly-scanned histopathological slides of head and neck tissues. In the context of computer-aided diagnosis, delineation of malignant regions is achieved using a powerful classification algorithm, which heavily depends on the features extracted by aid of a newly proposed cell nuclei clustering technique. The preliminary experimental results demonstrate a high accuracy of the proposed method.</p

    Treatment Using a Long Pulsed Nd:Yag Laser with a Pulsed Dye Laser for Four Cases of Blebbed Port Wine Stains

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    Port wine stains (PWS) are congenital capillary malformations consisting of ectasia of capillaries and venules. At birth,lesions are flat and relatively uniform in color, but evolve with age to become raised, thickened, irregularly surfaced, and deeply colored. Therefore, it is considered optimal to begin treatment of patients at an early age. Conventional treatment modalities, such as electrocautery or excision, require considerable effort and may be cosmetically unsatisfactory. We have performed treatment of blebbed PWS of four patients using a 1,064 nm long pulsed Nd:YAG laser with a contact cooling device. According to their size, most blebs required three or fewer treatment sessions at 8-week intervals. Treatments were well tolerated by all subjects and patients showed moderate to good improvement of blebs. A 1,064 nm long pulsed Nd:YAG laser with contact cooling may be considered as a promising therapeutic option for treatment of blebbed PWS

    Interstitial Photodynamic Therapy—A Focused Review

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    Multiple clinical studies have shown that interstitial photodynamic therapy (I-PDT) is a promising modality in the treatment of locally-advanced cancerous tumors. However, the utilization of I-PDT has been limited to several centers. The objective of this focused review is to highlight the different approaches employed to administer I-PDT with photosensitizers that are either approved or in clinical studies for the treatment of prostate cancer, pancreatic cancer, head and neck cancer, and brain cancer. Our review suggests that I-PDT is a promising treatment in patients with large-volume or thick tumors. Image-based treatment planning and real-time dosimetry are required to optimize and further advance the utilization of I-PDT. In addition, pre- and post-imaging using computed tomography (CT) with contrast may be utilized to assess the response

    Modelling Millimetre Wave Propagation and Absorption in a High Resolution Skin Model: The Effect of Sweat Glands

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    The aim of this work was to investigate the potential effect of sweat gland ducts (SGD) on specific absorption rate (SAR) and temperature distributions during mm-wave irradiation. High resolution electromagnetic and bio-heat transfer models of human skin with SGD were developed using a commercially available simulation software package (SEMCAD Xℱ). The skin model consisted of a 30 ÎŒm stratum corneum, 350 ÎŒm epidermis and papillary dermis (EPD) and 1000 ÎŒm dermis. Five SGD of 60 ÎŒm radius and 300 ÎŒm height were embedded linearly with 370 ÎŒm separation. A WR-10 waveguide positioned 20 ÎŒm from the skin surface and delivering 94 GHz electromagnetic radiation was included in the model. Saline conductivity was assigned inside SGD. SAR and temperatures were computed with and without SGD. Despite their small scale, SAR was significantly higher within SGD than in the EPD without SGD. Without SGD, SAR and temperature maxima were in the dermis near EPD. With SGD, SAR maximum was inside SGD while temperature maximum moved to the EPD/stratum-corneum junction. Since the EPD participates actively in perception, the effect of SGD should be taken into account in nociceptive studies involving mm-waves. This research represents a significant step towards higher spatial resolution numerical modelling of the skin and shows that microstructures can play a significant role in mm-wave absorption and induced temperature distributions

    The indentation response of GaAs-AlAs heterostructures

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    Low-load indentation has been used to investigate the deformation behaviour of a submicron layer of AlAs on a GaAs substrate. High-resolution scanning electron microscopy of cross-sections through the deformed regions under indentations into this structure reveals that the softer AlAs layer is not penetrated by the indenter and that unusual lateral cracking originates during the unloading phase. Data of intendation load against depth demonstrates the effect of the layer through the increase in composite hardness and elastic modulus with increasing load
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