Cardiac Cavity Segmentation in Echocardiography Using Triangle Equation

In this paper, cardiac cavity segmentation in echocardiography is proposed. The method uses triangle equation algorithms to detect and reconstruct the border. Prior to the application of both algorithms, some preprocessings have to be carried out. The first step is high boost filter to enhance high frequency component while still keeping the low frequency component. The second step is applying morphological and thresholding operations to eliminate noise and convert the image into binary image. The third step is negative laplacian filter to apply edge detector. The fourth step is region filter to eliminate small region. The last step is using triangle equation to detect and reconstruct the imprecise border. This technique is able to perform segmentation and detect border of cardiac cavity from echocardiographics sequences. Keywords: cardiac cavity, high boost filter, morphology, negative laplacian, region filter, and triangle equation

Development of Healthcare Kiosk for Checking Heart Health

The main problem encountered nowadays in the health field, especially in health care is the growing number of population and the decreasing health facilities. In this regard, healthcare kiosk is used as an alternative to the health care facilities. Heart disease is a dangerous one which could threaten human life. Many people have died due to heart disease and the surgery itself is still very expensive. To analyze heart diseases, doctor usually takes a video of the heart movement using ultrasound equipment to distinguish between normal and abnormal case. The results of analysis vary depending on the accuracy and experience of each doctor so it is difficult to determine the actual situation. Therefore, a method using healthcare kiosk to check the heart health is needed to help doctor and improve the health care facilities. The aim of this research is to develop healthcare kiosk which can be used to check the heart health. This research method is divided into three main parts: firstly, preprocessing to clarify the quality of the image.In this section, the writers propose a Median High Boost Filter method which is a combined method of Median Filtering and High Boost Filtering. Secondly, segmentation is used to obtain local cavities of the heart. In this part, the writers propose using Triangle Equation that is a new method to be developed. Thirdly, classification using Partial Monte Carlo method and artificial neural network method; these methods are used to measure the area of the heart cavity and discover the possibility of cardiac abnormalities. Methods for detecting heart health are placed in the kiosk. Therefore, it is expected to facilitate and improve the healthcare facilities.Keywords: Healthcare kiosk, heart health, reprocessing, segmentation, classification

Semi-automatic algorithm for construction of the left ventricular area variation curve over a complete cardiac cycle

<p>Abstract</p> <p>Background</p> <p>Two-dimensional echocardiography (2D-echo) allows the evaluation of cardiac structures and their movements. A wide range of clinical diagnoses are based on the performance of the left ventricle. The evaluation of myocardial function is typically performed by manual segmentation of the ventricular cavity in a series of dynamic images. This process is laborious and operator dependent. The automatic segmentation of the left ventricle in 4-chamber long-axis images during diastole is troublesome, because of the opening of the mitral valve.</p> <p>Methods</p> <p>This work presents a method for segmentation of the left ventricle in dynamic 2D-echo 4-chamber long-axis images over the complete cardiac cycle. The proposed algorithm is based on classic image processing techniques, including time-averaging and wavelet-based denoising, edge enhancement filtering, morphological operations, homotopy modification, and watershed segmentation. The proposed method is semi-automatic, requiring a single user intervention for identification of the position of the mitral valve in the first temporal frame of the video sequence. Image segmentation is performed on a set of dynamic 2D-echo images collected from an examination covering two consecutive cardiac cycles.</p> <p>Results</p> <p>The proposed method is demonstrated and evaluated on twelve healthy volunteers. The results are quantitatively evaluated using four different metrics, in a comparison with contours manually segmented by a specialist, and with four alternative methods from the literature. The method's intra- and inter-operator variabilities are also evaluated.</p> <p>Conclusions</p> <p>The proposed method allows the automatic construction of the area variation curve of the left ventricle corresponding to a complete cardiac cycle. This may potentially be used for the identification of several clinical parameters, including the area variation fraction. This parameter could potentially be used for evaluating the global systolic function of the left ventricle.</p

Traitement et exploration d'images TDM pour l'évaluation des bioprothèses valvulaires aortiques

Le but de cette étude est d évaluer la faisabilité de l analyse tomodensitométrique 3D des bioprothèses aortiques pour faciliter leur évaluation morphologique durant le suivi et d aider la sélection de cas et améliorer la planification d une procédure valvein-valve. Le challenge était représenté par le rehaussement des feuillets valvulaires, en raison d images très bruitées. Un angio-scanner synchronisé était réalisé chez des patients porteurs d une bioprotèses aortique dégénérée avant réintervention (images in-vivo). Différentes méthodes pour la réduction du bruit étaient proposées. La reconstruction tridimensionnelle des bioprothèses était réalisée en utilisant des méthodes de segmentation de régions par "sticks". Après réopération ces méthodes étaient appliquées aux images scanner des bioprothèses explantées (images ex-vivo) et utilisées comme référence. La réduction du bruit obtenue par le filtre stick modifié montrait meilleurs résultats en rapport signal/bruit en comparaison aux filtres de diffusion anisotropique. Toutes les méthodes de segmentation ont permis une reconstruction 3D des feuillets. L analyse qualitative a montré une bonne concordance entre les images obtenues in-vivo et les altérations des bioprothèses. Les résultats des différentes méthodes étaient comparés par critères volumétriques et discutés. Les bases d'une première approche de visualisation spatio-temporelle d'images TDM 3D+T de la prothèse valvulaire ont été proposés. Elle implique des techniques de rendu volumique et de compensation de mouvement. Son application à la valve native a aussi été envisagée. Les images scanner des bioprothèses aortiques nécessitent un traitement de débruitage et de réduction des artéfacts de façon à permettre le rehaussement des feuillets prothétiques. Les méthodes basées sticks semblent constituer une approche pertinente pour caractériser morphologiquement la dégénérescence des bioprothèses.The aim of the study was to assess the feasibility of CT based 3D analysis of degenerated aortic bioprostheses to make easier their morphological assessment. This could be helpful during regular follow-up and for case selection, improved planning and mapping of valve-in-valve procedure. The challenge was represented by leaflets enhancement because of highly noised CT images. Contrast-enhanced ECG-gated CT scan was performed in patients with degenerated aortic bioprostheses before reoperation (in-vivo images). Different methods for noise reduction were tested and proposed. 3D reconstruction of bioprostheses components was achieved using stick based region segmentation methods. After reoperation, segmentation methods were applied to CT images of the explanted prostheses (exvivo images). Noise reduction obtained by improved stick filter showed best results in terms of signal to noise ratio comparing to anisotropic diffusion filters. All segmentation methods applied to the best phase of in-vivo images allowed 3D bioprosthetic leaflets reconstruction. Explanted bioprostheses CT images were also processed and used as reference. Qualitative analysis revealed a good concordance between the in-vivo images and the bioprostheses alterations. Results from different methods were compared by means of volumetric criteria and discussed. A first approach for spatiotemporal visualization of 3D+T images of valve bioprosthesis has been proposed. Volume rendering and motion compensation techniques were applied to visualize different phases of CT data. Native valve was also considered. ECG-gated CT images of aortic bioprostheses need a preprocessing to reduce noise and artifacts in order to enhance prosthetic leaflets. Stick based methods seems to provide an interesting approach for the morphological characterization of degenerated bioprostheses.RENNES1-Bibl. électronique (352382106) / SudocSudocFranceF

Traitement et exploration d'images TDM pour l'évaluation des bioprothèses valvulaires aortiques

Le but de cette étude est d évaluer la faisabilité de l analyse tomodensitométrique 3D des bioprothèses aortiques pour faciliter leur évaluation morphologique durant le suivi et d aider la sélection de cas et améliorer la planification d une procédure valvein-valve. Le challenge était représenté par le rehaussement des feuillets valvulaires, en raison d images très bruitées. Un angio-scanner synchronisé était réalisé chez des patients porteurs d une bioprotèses aortique dégénérée avant réintervention (images in-vivo). Différentes méthodes pour la réduction du bruit étaient proposées. La reconstruction tridimensionnelle des bioprothèses était réalisée en utilisant des méthodes de segmentation de régions par "sticks". Après réopération ces méthodes étaient appliquées aux images scanner des bioprothèses explantées (images ex-vivo) et utilisées comme référence. La réduction du bruit obtenue par le filtre stick modifié montrait meilleurs résultats en rapport signal/bruit en comparaison aux filtres de diffusion anisotropique. Toutes les méthodes de segmentation ont permis une reconstruction 3D des feuillets. L analyse qualitative a montré une bonne concordance entre les images obtenues in-vivo et les altérations des bioprothèses. Les résultats des différentes méthodes étaient comparés par critères volumétriques et discutés. Les bases d'une première approche de visualisation spatio-temporelle d'images TDM 3D+T de la prothèse valvulaire ont été proposés. Elle implique des techniques de rendu volumique et de compensation de mouvement. Son application à la valve native a aussi été envisagée. Les images scanner des bioprothèses aortiques nécessitent un traitement de débruitage et de réduction des artéfacts de façon à permettre le rehaussement des feuillets prothétiques. Les méthodes basées sticks semblent constituer une approche pertinente pour caractériser morphologiquement la dégénérescence des bioprothèses.The aim of the study was to assess the feasibility of CT based 3D analysis of degenerated aortic bioprostheses to make easier their morphological assessment. This could be helpful during regular follow-up and for case selection, improved planning and mapping of valve-in-valve procedure. The challenge was represented by leaflets enhancement because of highly noised CT images. Contrast-enhanced ECG-gated CT scan was performed in patients with degenerated aortic bioprostheses before reoperation (in-vivo images). Different methods for noise reduction were tested and proposed. 3D reconstruction of bioprostheses components was achieved using stick based region segmentation methods. After reoperation, segmentation methods were applied to CT images of the explanted prostheses (exvivo images). Noise reduction obtained by improved stick filter showed best results in terms of signal to noise ratio comparing to anisotropic diffusion filters. All segmentation methods applied to the best phase of in-vivo images allowed 3D bioprosthetic leaflets reconstruction. Explanted bioprostheses CT images were also processed and used as reference. Qualitative analysis revealed a good concordance between the in-vivo images and the bioprostheses alterations. Results from different methods were compared by means of volumetric criteria and discussed. A first approach for spatiotemporal visualization of 3D+T images of valve bioprosthesis has been proposed. Volume rendering and motion compensation techniques were applied to visualize different phases of CT data. Native valve was also considered. ECG-gated CT images of aortic bioprostheses need a preprocessing to reduce noise and artifacts in order to enhance prosthetic leaflets. Stick based methods seems to provide an interesting approach for the morphological characterization of degenerated bioprostheses.RENNES1-Bibl. électronique (352382106) / SudocSudocFranceF

Construction d'un modèle per-opératoire 3D du rachis pour la navigation en thoracoscopie.

RÉSUMÉ: Lors de discectomie par thoracoscopie, les outils de visualisation procurent peu d’information de profondeur et le champ de visualisation de la caméra miniature insérée dans le patient est relativement restreint. Aussi, le mouvement simultané de la caméra et des instruments chirurgicaux peut provoquer une désorientation. Ainsi, la courbe d’apprentissage pour l’utilisation de cette technologie est très abrupte et un nombre restreint de chirurgiens choisissent l’intervention minimalement invasive malgré les avantages qu’elle peut procurer aux patients. En effet la discectomie par thoracoscopie réduit les pertes sanguines, le traumatisme des tissus entourant le disque afin d’accéder à la zone d’intérêt et le temps d’hospitalisation. Les discectomies sont prescrites à certains patients scoliotiques afin de redonner de la flexibilité à la colonne avant l’instrumentation (pose de vis et tige pour corriger la déformation). La résection du disque intervertébral est faite partiellement et la quantité du disque réséqué dépend du degré de flexibilité que le chirurgien désire redonner au patient. En effectuant la discectomie par thoracoscopie, il est impossible pour le chirurgien de visualiser rapidement la quantité de disque restant en plus d’avoir les désavantages de désorientation et de petit champ de vision de la caméra miniature insérée dans le patient. Il est donc pertinent de tenter de réduire les problèmes de visualisation rencontrés lors des thoracoscopies en procurant au chirurgien la possibilité d’examiner en 3D les structures anatomiques du patient pendant la chirurgie sans ajouter de radiations supplémentaires au patient. Ce système d’assistance permettrait également d’accroître la sécurité du patient et la qualité de la chirurgie en donnant aux chirurgiens la possibilité de localiser en 3D la moelle épinière et en leur donnant également la possibilité de visualiser la quantité de disque restant. Ainsi, l’intérêt de fusionner les images vidéo avec un modèle pré-opératoire 3D est alors tout indiqué.---------- ABSTRACT: Visualization tools available while doing thoracoscopic diskectomy do not show depth information and the field of view of the miniaturized camera inserted into the patient is small. Also, simultaneous movement of the camera and surgical tools may result in disorientation. The learning curve for the use of this technology is very steep and numbers of surgeons choose not to use minimally invasive surgery despite important advantages for the patients. Indeed, thoracoscopic diskectomy reduce blood loss, trauma of surrounding soft tissues to access intervertebral disks and hospitalization time. Diskectomy are prescribed to specific scoliotic patients to gain flexibility of the spine before instrumentation surgery (fixation of screws and rod to correct the deformation). The intervertebral disk is partly resected depending on the level of flexibility the patient has to gain according to the surgeon. During thoracoscopic diskectomy, it is impossible for the surgeon to rapidly visualize the remaining disk tissue and this further increase the disadvantages for the surgeons. Hence, it is relevant to try to reduce visualization problems encountered during thoracoscopic diskectomy by providing to the surgeons a 3D view of the whole spine during the surgery, without adding supplementary radiation to the patient. The computer assisted surgery system would also increase the security of the patient by allowing the surgeons to localize rapidly in 3D the spinal canal as well as the remaining disk. The fusion of the video images with 3D spine of the patient is of great interest for the surgeons

Técnicas imagiológicas para tele-ecografia assistida por robô

O objectivo deste trabalho consiste na reconstrução tridimensional (3D) de objectos a partir de um conjunto de imagens ecográficas obtidas a partir de movimentos de rotação de uma sonda ecográfica, acoplada na extremidade de um robô manipulador. A cada imagem adquirida foi extraída a sua matriz de transformação respectiva que dá a informação da sua posição e orientação relativamente à base do robô. O objecto de estudo foi um balão convencional em forma de coração, cheio de água que por sua vez foi mergulhado em água. Como estudo inicial, foi tida em conta informação acerca da manipulação robótica e controlo da sonda ecográfica no seu espaço de tarefa. Seguidamente, foram abordadas temáticas de processamento de imagem médica ecográfica, nomeadamente ecocardiográfica, e assim o levantamento das características e problemáticas que esse tipo de imagem implicava. Foram estudados vários métodos de segmentação de imagem bidimensional de ecocardiografia, entre eles, o método de level set de Chan e Vese e o método de Kass e Terzopoulos baseado em modelos de snakes. O modelo de Chan e Vese não foi completamente satisfatório para a segmentação das cavidades cardíacas, não fornecendo cavidades cardíacas fechadas. Por sua vez, o modelo snake funcionou muito bem na segmentação das imagens ecográficas do balão, induzindo uma reconstrução 3D offline de uma estrutura. Este trabalho passou também por um abrangente estudo científico que levou à implementação e simulação de um algoritmo de reconstrução 3D offline em linguagem Matlab2009b, fazendo uso das posições dos contornos obtidos da segmentação de Kass e Terzopoulos. Foram ainda realizados vários testes experimentais que validaram o método de reconstrução 3D proposto. Estes resultados abrem caminho para uma reconstrução 3D em tempo real de imagens ecográficas, utilizando um sistema robótic

Watershed-presegmented snake for boundary detection and tracking of left ventricle in echocardiographic images

In this paper,an automated method of boundary detection of the left ventricle (LV) is proposed. The method uses a watershed transform and morphological operation to locate the region containing the LV,then performs snake deformation with a multiscale directional edge map for the detection of the endocardial boundary of the LV.Accepted versio