140 research outputs found

    A Decision Support System (DSS) for Breast Cancer Detection Based on Invariant Feature Extraction, Classification, and Retrieval of Masses of Mammographic Images

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    This paper presents an integrated system for the breast cancer detection from mammograms based on automated mass detection, classification, and retrieval with a goal to support decision-making by retrieving and displaying the relevant past cases as well as predicting the images as benign or malignant. It is hypothesized that the proposed diagnostic aid would refresh the radiologist’s mental memory to guide them to a precise diagnosis with concrete visualizations instead of only suggesting a second diagnosis like many other CAD systems. Towards achieving this goal, a Graph-Based Visual Saliency (GBVS) method is used for automatic mass detection, invariant features are extracted based on using Non-Subsampled Contourlet transform (NSCT) and eigenvalues of the Hessian matrix in a histogram of oriented gradients (HOG), and finally classification and retrieval are performed based on using Support Vector Machines (SVM) and Extreme Learning Machines (ELM), and a linear combination-based similarity fusion approach. The image retrieval and classification performances are evaluated and compared in the benchmark Digital Database for Screening Mammography (DDSM) of 2604 cases by using both the precision-recall and classification accuracies. Experimental results demonstrate the effectiveness of the proposed system and show the viability of a real-time clinical application

    Feature Extraction and Classification of Automatically Segmented Lung Lesion Using Improved Toboggan Algorithm

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    The accurate detection of lung lesions from computed tomography (CT) scans is essential for clinical diagnosis. It provides valuable information for treatment of lung cancer. However, the process is exigent to achieve a fully automatic lesion detection. Here, a novel segmentation algorithm is proposed, it's an improved toboggan algorithm with a three-step framework, which includes automatic seed point selection, multi-constraints lesion extraction and the lesion refinement. Then, the features like local binary pattern (LBP), wavelet, contourlet, grey level co-occurence matrix (GLCM) are applied to each region of interest of the segmented lung lesion image to extract the texture features such as contrast, homogeneity, energy, entropy and statistical extraction like mean, variance, standard deviation, convolution of modulated and normal frequencies. Finally, support vector machine (SVM) and K-nearest neighbour (KNN) classifiers are applied to classify the abnormal region based on the performance of the extracted features and their performance is been compared. The accuracy of 97.8% is been obtained by using SVM classifier when compared to KNN classifier. This approach does not require any human interaction for lesion detection. Thus, the improved toboggan algorithm can achieve precise lung lesion segmentation in CT images. The features extracted also helps to classify the lesion region of lungs efficiently

    Hybrid Discrete Wavelet Transform and Gabor Filter Banks Processing for Features Extraction from Biomedical Images

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    A new methodology for automatic feature extraction from biomedical images and subsequent classification is presented. The approach exploits the spatial orientation of high-frequency textural features of the processed image as determined by a two-step process. First, the two-dimensional discrete wavelet transform(DWT) is applied to obtain the HH high-frequency subband image. Then, a Gabor filter bank is applied to the latter at different frequencies and spatial orientations to obtain new Gabor-filtered image whose entropy and uniformity are computed. Finally, the obtained statistics are fed to a support vector machine (SVM) binary classifier. The approach was validated on mammograms, retina, and brain magnetic resonance (MR) images.The obtained classification accuracies show better performance in comparison to common approaches that use only the DWT or Gabor filter banks for feature extraction

    Medical image processing: applications in ophthalmology and total hip replacement

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    Medical imaging tools technologically supported by the recent advances in the areas of computer vision can provide systems that aid medical professionals to carry out their expert diagnostics and investigations more effectively and efficiently. Two medical application domains that can benefit by such tools are ophthalmology and Total Hip Replacement (THR). Although a literature review conducted within the research context of this thesis revealed a number of existing solutions these are either very much limited by their application scope, robustness or scope of the extensiveness of the functionality made available. Therefore this thesis focuses on initially investigating a number of requirements defined by leading experts in the respective specialisms and providing practical solutions, well supported by the theoretical advances of computer vision and pattern recognition. This thesis provides three novel algorithms/systems for use within image analysis in the areas of Ophthalmology and THR. The first approach uses Contourlet Transform to analyse and quantify corneal neovascularization. Experimental results are provided to prove that the proposed approach provides improved robustness in the presence of noise, non-uniform illumination and reflections, common problems that exist in captured corneal images. The second approach uses a colour based segmentation approach to segment, measure and analyse corneal ulcers using the HVS colour space. Literature review conducted within the research context of this thesis revealed that there is no such system available for analysis and measurement of corneal ulcers. Finally the thesis provides a robust approach towards detecting and analysing possible dislocations and misalignments in THR X-ray images. The algorithm uses localised histogram equalisation to enhance the quality of X-ray images first prior to using Hough Transforms and filtered back projections to locate and recognise key points of the THR x-ray images. These key points are then used to measure the possible presence of dislocations and misalignments. The thesis further highlights possible extensions and improvements to the proposed algorithms and systems

    MEME KANSERİ TANISI İÇİN DERİN ÖZNİTELİK TABANLI KARAR DESTEK SİSTEMİ

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    Meme kanseri, akciğer kanserinden sonra kadınlarda kanser ölümlerinin ikinci önemli sebebidir. Erken tanı, meme kanseri tedavisinde oldukça önemlidir. Mamografi, meme kanserinin erken teşhisinde en çok kullanılan görüntüleme tekniğidir. Yapılan araştırmalar, 50 yaşın üstünde düzenli mamografi çektirmenin kadınlar için ölüm oranını %30 oranında azaltabileceğini göstermektedir. Ancak, mamogramların yorumlanması genellikle özneldir.Bu çalışmada, göğüs kitlelerinin otomatik tespiti, sınıflandırılması ve içerik tabanlı erişimi için entegre bir sistem sunulmuştur. Bu kapsamda, hekimlerin kitle hakkındaki kararları, üst düzey derin öznitelikler ve düşük seviye öznitelik seti ile ifade edilmiştir. Önerilen sistemde düşük seviyeli öznitelikleri elde etmek için, kitle tespitinde graf tabanlı görsel çıkıntı yöntemi kullanılmış ve öznitelik çıkarımı için örneklemesiz contourlet dönüşümü ve eig(Hess)-HOG yöntemleri kullanılmıştır. Ayrıca, yüksek seviyeli evrişimsel sinir ağı öznitelikleri kullanılmıştır. Ardından, test görüntülerinin kategorisini tahmin etmek için yukarıda bahsedilen özniteliklere dayalı iki aşırı öğrenme makinesi (AÖM) sınıflandırıcısı kullanılmıştır. Farklı özniteliklere dayalı sınıflandırıcıların sonuçları, test görüntülerinin türünü belirlemek için analiz edilmiştir. Görüntü erişimi ve sınıflandırma performansları, hem kesinlik-duyarlılık hem de sınıflandırma doğrulukları kullanarak IRMA mammographic patches veri setinde değerlendirilip ve karşılaştırılmıştır. Deneysel sonuçlar, önerilen sistemin etkililiğini ve gerçek zamanlı klinik uygulamalardaki kullanılabilirliğini göstermektedir
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