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1.
Chinese Journal of Medical Instrumentation ; (6): 157-162, 2009.
Artigo em Chinês | WPRIM | ID: wpr-329353

RESUMO

Ultrasound image has a lot of speckle noise, which brings great difficulties to the feature extraction, recognition and analysis. Especially in the edge extraction, the conventional extraction algorithms are difficult to achieve the desired results because of the speckle noise. To solve this problem, an algorithm based on the anisotropic diffusion equation is presented. The new algorithm combines the robust estimation and considers the characteristic of the speckle noise, so it can suppress the speckle noise effectively and be more robust, thus the edge details of the ultrasound image can be preserved even enhanced, which can provide effective safeguard for the following edge extraction. Furthermore, the paper proposes a new method to compute speckle scale coefficients automatically, which reduces the influence of the human beings, and enhances the stability of the algorithm.


Assuntos
Algoritmos , Artefatos , Interpretação de Imagem Assistida por Computador , Ultrassonografia , Métodos
2.
Chinese Journal of Medical Instrumentation ; (6): 186-189, 2008.
Artigo em Chinês | WPRIM | ID: wpr-309617

RESUMO

This paper proposes an algorithm of evaluating the compression depth, and then to extract four normalized mammary elasticity characteristic parameters with respect to the compression depth. The classification experiments show that these elasticity parameters have a good capability in determining whether the tumor is benign or malignant, and if combined with morphological parameters, the accuracy, sensitivity and specificity can be improved and increased to 95.19%, 98.82% and 92.16%, respectively.


Assuntos
Feminino , Humanos , Algoritmos , Neoplasias da Mama , Diagnóstico por Imagem , Técnicas de Imagem por Elasticidade , Sensibilidade e Especificidade , Ultrassonografia Mamária , Métodos
3.
Chinese Journal of Medical Instrumentation ; (6): 316-358, 2008.
Artigo em Chinês | WPRIM | ID: wpr-309587

RESUMO

In this paper, we propose that, the need of the costly re-initialization procedure can be completely eliminated by using the variation formulation, thus increasing the speed of computing operations. The edge detecting function in the geodesic active contour model is improved by incorporating a prior knowledge. The accuracy of the segmentation algorithm can be enhanced by using the minimal variance. Experimental results show that the proposed algorithm can segment the prostate ultrasound images effectively and avoid the problem of contour leakage.


Assuntos
Humanos , Masculino , Algoritmos , Interpretação de Imagem Assistida por Computador , Métodos , Reconhecimento Automatizado de Padrão , Métodos , Próstata , Diagnóstico por Imagem , Ultrassonografia , Métodos
4.
Chinese Journal of Medical Instrumentation ; (6): 323-327, 2008.
Artigo em Chinês | WPRIM | ID: wpr-309585

RESUMO

A filtering algorithm is proposed to deal with the medical ultrasonic image series in video format, which uses the relativity in spatial domain, gray value domain and temporal domain simultaneously. For each frame image, the relativity in spatial domain and gray value domain is utilized to construct the adaptive neighborhood first. Then the spatial weighted and gray value weighted filtering is performed in this neighborhood. Finally, the temporal relativity between the adjacent frames is used to perform the temporal weighted filtering. All the weighted filtering in the three domains uses Gaussian kernel, thus the filtering sensitivity resulting from the threshold selection is reduced, and the stability of the algorithm is enhanced. As it can be seen from the experimental results, the three-domains filtering algorithm can suppress the noise effectively, and the edge details can be reserved well. So it is useful for the feature extraction, recognition and analysis.


Assuntos
Algoritmos , Interpretação de Imagem Assistida por Computador , Métodos , Ultrassonografia , Métodos
5.
Chinese Journal of Medical Instrumentation ; (6): 398-401, 2008.
Artigo em Chinês | WPRIM | ID: wpr-309567

RESUMO

This paper presents a computer-aided diagnosis method for prostate cancer detection using Trans-rectal ultrasound(TRUS) images. Firstly, statistical texture analysis is implemented in every ROI in segmented prostate images. From each ROI, grey level difference vector features, edge-frequency features and texture features in frequency domain are constructed. Then, the number of features is reduced using ANOVA statistics to select the optimal feature subset. Finally, SVM is applied to the selected subset for detecting the cancer regions. Experimental results show that the proposed algorithm can recognize and detect the cancer images effectively so as to supply essential information for a diagnosis.


Assuntos
Humanos , Masculino , Algoritmos , Inteligência Artificial , Interpretação de Imagem Assistida por Computador , Métodos , Redes Neurais de Computação , Neoplasias da Próstata , Diagnóstico por Imagem , Processamento de Sinais Assistido por Computador , Ultrassonografia
6.
Chinese Journal of Medical Instrumentation ; (6): 239-241, 2007.
Artigo em Chinês | WPRIM | ID: wpr-323278

RESUMO

This paper proposes a tree-structured wavelet algorithm for brain CT texture feature extraction. This algorithm is used to analyse subimages automatically and to choose the optimum subimage for feature extraction. Experimental results show that this algorithm can improve the performance of brain CT texture feature extraction.


Assuntos
Humanos , Algoritmos , Encéfalo , Diagnóstico por Imagem , Processamento de Imagem Assistida por Computador , Tomografia Computadorizada por Raios X , Métodos
7.
Chinese Journal of Medical Instrumentation ; (6): 395-399, 2007.
Artigo em Chinês | WPRIM | ID: wpr-323248

RESUMO

This paper proposes an improved C-V model, which can avoid the step of re-initialization and simplify the formation of the initial level set function, thus the speed of segmentation can be accelerated greatly. Furthermore, based on the grayscale distribution characteristics of the breast tumor ultrasound images and on the hypothesis of piecewise constant in the C-V model, a semiautomatic segmentation flow has been presented, in which the rough contour is sketched first, and then a subimage would be obtained for the refined segmentation algorithm. This flow has improved not only the accuracy, but also the efficiency of the segmentation algorithm. The experiments show that the proposed algorithm could extract the contour of the breast tumor from the ultrasound images efficiently and accurately, which is fundamentally important for the following target feature extraction and analysis.


Assuntos
Feminino , Humanos , Algoritmos , Neoplasias da Mama , Diagnóstico por Imagem , Interpretação de Imagem Assistida por Computador , Métodos , Ultrassonografia Mamária , Métodos
8.
Chinese Journal of Medical Instrumentation ; (6): 316-320, 2005.
Artigo em Chinês | WPRIM | ID: wpr-232945

RESUMO

In this paper, a new, fully-automatic method for the quantification of brain atrophy based on CT volume data is put forward by taking advantage of the characteristics of cerebral CT images in combination with the prior medical knowledge. This algorithm has been verified through the calculation of 2388 cases of normal and brain atrophy subjects.


Assuntos
Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Humanos , Lactente , Pessoa de Meia-Idade , Adulto Jovem , Algoritmos , Autoanálise , Métodos , Encéfalo , Diagnóstico por Imagem , Doença de Pick , Diagnóstico por Imagem , Tomografia Computadorizada por Raios X , Métodos
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