Pub Date : 2001-06-10DOI: 10.1109/MIAR.2001.930278
I. Maros, K. Thielemans
Ultimately, positron emission tomography (PET) image reconstruction boils down to solving an overdetermined system of linear equations with nonnegative variables. The latter requirement gets a natural treatment if the problem is reformulated as an optimization problem. The deviation /spl par/Ax-b/spl par/ can be measured by different vector norms leading to different optimization problems. In the paper we give some preliminary results of our investigations about the usefulness of advanced optimization techniques for the solution of different formulations of the problem.
{"title":"PET image reconstruction by vector norm optimization","authors":"I. Maros, K. Thielemans","doi":"10.1109/MIAR.2001.930278","DOIUrl":"https://doi.org/10.1109/MIAR.2001.930278","url":null,"abstract":"Ultimately, positron emission tomography (PET) image reconstruction boils down to solving an overdetermined system of linear equations with nonnegative variables. The latter requirement gets a natural treatment if the problem is reformulated as an optimization problem. The deviation /spl par/Ax-b/spl par/ can be measured by different vector norms leading to different optimization problems. In the paper we give some preliminary results of our investigations about the usefulness of advanced optimization techniques for the solution of different formulations of the problem.","PeriodicalId":375408,"journal":{"name":"Proceedings International Workshop on Medical Imaging and Augmented Reality","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122595194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-06-10DOI: 10.1109/MIAR.2001.930260
Charlie Sim, W. Ng, M. Teo, Yong-Chong Loh, T. Yeo
In robotic skull-base surgery, a surgical navigation and planning station is used to plan the path to be taken by the bone removal tool which is carried by a robotic manipulator. In planning for such a path, considerations have to be taken in terms of the manipulator characteristics and the geometric properties of the bone removal tool used. Presented in this paper is a methodology which takes into account the required efficacy of surgical planning. Differing from other surgical planning methodologies, the final output of the planned surgery can be directly executed by a surgical robot (NeuRobot). In doing so, the surgeon has only to specify the region or features within the skull-base which are to be avoided and the general direction of action which specifies the eventual path that the surgery is to be carried out. A novel approach is taken by the use of Voronoi maps to identify "safe" cavities on each image slice.
{"title":"Image-guided manipulator compliant surgical planning methodology for robotic skull-base surgery","authors":"Charlie Sim, W. Ng, M. Teo, Yong-Chong Loh, T. Yeo","doi":"10.1109/MIAR.2001.930260","DOIUrl":"https://doi.org/10.1109/MIAR.2001.930260","url":null,"abstract":"In robotic skull-base surgery, a surgical navigation and planning station is used to plan the path to be taken by the bone removal tool which is carried by a robotic manipulator. In planning for such a path, considerations have to be taken in terms of the manipulator characteristics and the geometric properties of the bone removal tool used. Presented in this paper is a methodology which takes into account the required efficacy of surgical planning. Differing from other surgical planning methodologies, the final output of the planned surgery can be directly executed by a surgical robot (NeuRobot). In doing so, the surgeon has only to specify the region or features within the skull-base which are to be avoided and the general direction of action which specifies the eventual path that the surgery is to be carried out. A novel approach is taken by the use of Voronoi maps to identify \"safe\" cavities on each image slice.","PeriodicalId":375408,"journal":{"name":"Proceedings International Workshop on Medical Imaging and Augmented Reality","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132712855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-06-10DOI: 10.1109/MIAR.2001.930273
K. Qin, Huawei Wang, Denggao Li, R. Kikinis, M. Halle
In this paper a physics-based dynamic subdivision surface model based on Catmull-Clark surfaces is introduced and a new technique for exact evaluation of the dynamic model parameters, such as mass, damping and stiffness matrices, and dynamic forces etc. is presented for the dynamic subdivision surface. A closed-form analytic formula for thin-plate energy of Catmull-Clark surfaces of arbitrary topology is derived, which does not require recursive subdivision for calculating the dynamic parameters, so that it is more efficient and fast than the existing methods published for such dynamic models. This new strategy can be used for deformable surface modeling, medical imaging and simulation and so on.
{"title":"Physics-based subdivision surface modeling for medical imaging and simulation","authors":"K. Qin, Huawei Wang, Denggao Li, R. Kikinis, M. Halle","doi":"10.1109/MIAR.2001.930273","DOIUrl":"https://doi.org/10.1109/MIAR.2001.930273","url":null,"abstract":"In this paper a physics-based dynamic subdivision surface model based on Catmull-Clark surfaces is introduced and a new technique for exact evaluation of the dynamic model parameters, such as mass, damping and stiffness matrices, and dynamic forces etc. is presented for the dynamic subdivision surface. A closed-form analytic formula for thin-plate energy of Catmull-Clark surfaces of arbitrary topology is derived, which does not require recursive subdivision for calculating the dynamic parameters, so that it is more efficient and fast than the existing methods published for such dynamic models. This new strategy can be used for deformable surface modeling, medical imaging and simulation and so on.","PeriodicalId":375408,"journal":{"name":"Proceedings International Workshop on Medical Imaging and Augmented Reality","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133352722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-06-10DOI: 10.1109/MIAR.2001.930307
Jianyun Chai, Jian Sun, Zesheng Tang
Surgery simulation has been found very useful in surgery planning and training. In order to obtain a physically realistic surgery simulation, it is needed to treat the deformation of soft tissues with nonlinear elastic properties and changeable topologies in real time. Most of the real-time approaches to soft tissue deformation used so far, however, have less functions. In this paper, an improved algorithm, called Hybrid FEM, is proposed to include the two vital factors into a unified framework, which generalizes the use of FEM in surgery simulation. Since the effects of nonlinear properties and topology changes on the deformation of soft tissues often appear locally around the operating positions, only the model of FEM for that limited region should be updated as the operation is performed; while the model for other regions can be kept constant. The Hybrid FEM algorithm has been implemented and examples are given to show the validity of the algorithm.
{"title":"Hybrid FEM for deformation of soft tissues in surgery simulation","authors":"Jianyun Chai, Jian Sun, Zesheng Tang","doi":"10.1109/MIAR.2001.930307","DOIUrl":"https://doi.org/10.1109/MIAR.2001.930307","url":null,"abstract":"Surgery simulation has been found very useful in surgery planning and training. In order to obtain a physically realistic surgery simulation, it is needed to treat the deformation of soft tissues with nonlinear elastic properties and changeable topologies in real time. Most of the real-time approaches to soft tissue deformation used so far, however, have less functions. In this paper, an improved algorithm, called Hybrid FEM, is proposed to include the two vital factors into a unified framework, which generalizes the use of FEM in surgery simulation. Since the effects of nonlinear properties and topology changes on the deformation of soft tissues often appear locally around the operating positions, only the model of FEM for that limited region should be updated as the operation is performed; while the model for other regions can be kept constant. The Hybrid FEM algorithm has been implemented and examples are given to show the validity of the algorithm.","PeriodicalId":375408,"journal":{"name":"Proceedings International Workshop on Medical Imaging and Augmented Reality","volume":"142 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115477218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-06-10DOI: 10.1109/MIAR.2001.930281
Francis K. H. Quek, C. Kirbas, F. Charbel
We propose a model for the interactive interpretation of medical images pertaining to human neurovascular system. This attentionally-based interactive model, ATM, is founded upon human selective attention. AIM combines human operator's high level reasoning with machine perception and exploits human interaction as part of the solution. AIM defines two channels of interaction: context ("what to look for"), and focus-of-attention ("where to look") by which the user directs the attention of the machine perception. AIM facilitates varying degrees of human intervention in the process by providing four levels of abstraction for the context information. This hierarchy of context abstractions permits the system to function more autonomously (doing high-level tasks like extracting an arterial vessel) in routine interpretation, and to require more user intervention (e.g. locating arterial wall boundaries) as the image complexity increases or data quality worsen. This is important in medical imaging where the users demand ultimate control and confidence in the system. Such technology can contribute significantly on the design of radiological imaging systems.
{"title":"AIM: an attentionally-based system for the interpretation of angiography","authors":"Francis K. H. Quek, C. Kirbas, F. Charbel","doi":"10.1109/MIAR.2001.930281","DOIUrl":"https://doi.org/10.1109/MIAR.2001.930281","url":null,"abstract":"We propose a model for the interactive interpretation of medical images pertaining to human neurovascular system. This attentionally-based interactive model, ATM, is founded upon human selective attention. AIM combines human operator's high level reasoning with machine perception and exploits human interaction as part of the solution. AIM defines two channels of interaction: context (\"what to look for\"), and focus-of-attention (\"where to look\") by which the user directs the attention of the machine perception. AIM facilitates varying degrees of human intervention in the process by providing four levels of abstraction for the context information. This hierarchy of context abstractions permits the system to function more autonomously (doing high-level tasks like extracting an arterial vessel) in routine interpretation, and to require more user intervention (e.g. locating arterial wall boundaries) as the image complexity increases or data quality worsen. This is important in medical imaging where the users demand ultimate control and confidence in the system. Such technology can contribute significantly on the design of radiological imaging systems.","PeriodicalId":375408,"journal":{"name":"Proceedings International Workshop on Medical Imaging and Augmented Reality","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124700421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-06-10DOI: 10.1109/MIAR.2001.930294
T. Kondo, S. Ong, Joon Huang Chuah, K. Foong
We present an automated method for determining the dental arch form, detecting the interstices between teeth, and segmenting the posterior teeth in 3D images of dental plaster models. The dental arch form is obtained by a robust two-step curve fitting method that can handle dental models with not only well-aligned but also malaligned teeth. The interstices between teeth are detected by searching for valleys along the dental arch form. We employ a FIR band-pass filter to facilitate the valley detection. Plan-view and front-view range images are utilized for the detection of teeth interstices. The posterior teeth are segmented by tracing edges using the inner product of gradient vectors.
{"title":"Robust arch detection and tooth segmentation in 3D images of dental plaster models","authors":"T. Kondo, S. Ong, Joon Huang Chuah, K. Foong","doi":"10.1109/MIAR.2001.930294","DOIUrl":"https://doi.org/10.1109/MIAR.2001.930294","url":null,"abstract":"We present an automated method for determining the dental arch form, detecting the interstices between teeth, and segmenting the posterior teeth in 3D images of dental plaster models. The dental arch form is obtained by a robust two-step curve fitting method that can handle dental models with not only well-aligned but also malaligned teeth. The interstices between teeth are detected by searching for valleys along the dental arch form. We employ a FIR band-pass filter to facilitate the valley detection. Plan-view and front-view range images are utilized for the detection of teeth interstices. The posterior teeth are segmented by tracing edges using the inner product of gradient vectors.","PeriodicalId":375408,"journal":{"name":"Proceedings International Workshop on Medical Imaging and Augmented Reality","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122920348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-06-10DOI: 10.1109/MIAR.2001.930290
A. Rao, D. Gillies
We present a new method for extracting vortex structures from 2D blood flow field images. The new technique first identifies vortex centres in the velocity field, and then grows regions about these points using a criterion based on the Jacobeans evaluated at the candidate points, and the size and shape of the region already determined. A convexity constraint is also employed to enforce coherency in the resulting regions. The algorithm accounts for the asymmetry and nonlinearity in vortex structures while maintaining the concept of a vortex centre. We present results of the method obtained from synthetic data and a blood flow velocity image.
{"title":"Vortex segmentation from cardiac MR 2D velocity images using region growing about vortex centres","authors":"A. Rao, D. Gillies","doi":"10.1109/MIAR.2001.930290","DOIUrl":"https://doi.org/10.1109/MIAR.2001.930290","url":null,"abstract":"We present a new method for extracting vortex structures from 2D blood flow field images. The new technique first identifies vortex centres in the velocity field, and then grows regions about these points using a criterion based on the Jacobeans evaluated at the candidate points, and the size and shape of the region already determined. A convexity constraint is also employed to enforce coherency in the resulting regions. The algorithm accounts for the asymmetry and nonlinearity in vortex structures while maintaining the concept of a vortex centre. We present results of the method obtained from synthetic data and a blood flow velocity image.","PeriodicalId":375408,"journal":{"name":"Proceedings International Workshop on Medical Imaging and Augmented Reality","volume":"6 12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128421087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-06-10DOI: 10.1109/MIAR.2001.930284
Weiqiang Liu, Peihua Shen, Yingge Qu, De-Shen Xia
In this paper a method of lung cancer aid diagnosis using support vector machines is proposed. Combined with the knowledge of pathology, the improvement of sequential minimal optimization (SMO) is achieved by the introduction of game theory to accelerate the training process. The experimental result shows that the speed increased greatly. And comparing with other systems, the diagnosis identification rate of the three main kinds of cancer cells is also increased.
{"title":"Fast algorithm of support vector machines in lung cancer diagnosis","authors":"Weiqiang Liu, Peihua Shen, Yingge Qu, De-Shen Xia","doi":"10.1109/MIAR.2001.930284","DOIUrl":"https://doi.org/10.1109/MIAR.2001.930284","url":null,"abstract":"In this paper a method of lung cancer aid diagnosis using support vector machines is proposed. Combined with the knowledge of pathology, the improvement of sequential minimal optimization (SMO) is achieved by the introduction of game theory to accelerate the training process. The experimental result shows that the speed increased greatly. And comparing with other systems, the diagnosis identification rate of the three main kinds of cancer cells is also increased.","PeriodicalId":375408,"journal":{"name":"Proceedings International Workshop on Medical Imaging and Augmented Reality","volume":"2011 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128188824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-06-10DOI: 10.1109/MIAR.2001.930293
R. Minamikawa-Tachino, H. Sakuraba, Yumi Yamaguchi, I. Fujishiro
This paper proposes a new algorithm, called Voxel Stuffing, to reconstruct single high-quality volume data from multiple sparsely-spaced sequences of cross-sectional images acquired by magnetic resonance imaging (MRI). Although fine and isotropic cross-sectional images can be obtained by using the most advanced MRI facilities, sparse sampling is commonly performed in the clinical examination. Intensive feasibility study was performed with three regular grid volume data sets, whose sources include an analytic function; a numerical simulation; and measurements. In either case, the Voxel Stuffing algorithm generates a higher-quality volume data from triple sequences of cross-sectional images in comparison with any volume data reconstructed linearly from a single sequence of class-sectional images. The Voxel Stuffing algorithm is extended to reconstruct a rectilinearly structured volume data set from triple non-orthogonal sequences of cross-sectional images, which are taken commonly in the general MRI clinical examination. The effectiveness of the extended Voxel Stuffing algorithm is illustrated with an MRI data set for a human brain containing a tumor.
{"title":"Voxel Stuffing: high-quality volume interpolation from multiple sequences of cross-sectional images","authors":"R. Minamikawa-Tachino, H. Sakuraba, Yumi Yamaguchi, I. Fujishiro","doi":"10.1109/MIAR.2001.930293","DOIUrl":"https://doi.org/10.1109/MIAR.2001.930293","url":null,"abstract":"This paper proposes a new algorithm, called Voxel Stuffing, to reconstruct single high-quality volume data from multiple sparsely-spaced sequences of cross-sectional images acquired by magnetic resonance imaging (MRI). Although fine and isotropic cross-sectional images can be obtained by using the most advanced MRI facilities, sparse sampling is commonly performed in the clinical examination. Intensive feasibility study was performed with three regular grid volume data sets, whose sources include an analytic function; a numerical simulation; and measurements. In either case, the Voxel Stuffing algorithm generates a higher-quality volume data from triple sequences of cross-sectional images in comparison with any volume data reconstructed linearly from a single sequence of class-sectional images. The Voxel Stuffing algorithm is extended to reconstruct a rectilinearly structured volume data set from triple non-orthogonal sequences of cross-sectional images, which are taken commonly in the general MRI clinical examination. The effectiveness of the extended Voxel Stuffing algorithm is illustrated with an MRI data set for a human brain containing a tumor.","PeriodicalId":375408,"journal":{"name":"Proceedings International Workshop on Medical Imaging and Augmented Reality","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125153835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-06-10DOI: 10.1109/MIAR.2001.930279
R. Merrifield, J. Keegan, D. Firmin, Guang-Zhong Yang
The combination of computational fluid dynamics and in vivo imaging techniques such as cardiovascular magnetic resonance (CMR) allows the calculation of blood flow indices that cannot be measured directly. This combined strategy requires the provision of accurate anatomical delineation of cardiovascular structure as well as boundary flow conditions. Thus far, an automatic method for structure segmentation has yet to be developed. The purpose of this paper is to present a novel imaging strategy, based on contrast enhancement characteristics of TrueFISP CMR, that allows the signal intensities of blood and myocardium of the Left Ventricle (LV) to be extracted without user interaction. This has been used to provide a fully automatic segmentation of the LV endocardial border allowing the creation of models suitable for CFD analysis. The method has been validated with data acquired from 10 asymptomatic subjects. The results have shown to be comparable to that of manual delineation by experienced observers.
{"title":"A novel imaging strategy for structural segmentation of the left ventricle","authors":"R. Merrifield, J. Keegan, D. Firmin, Guang-Zhong Yang","doi":"10.1109/MIAR.2001.930279","DOIUrl":"https://doi.org/10.1109/MIAR.2001.930279","url":null,"abstract":"The combination of computational fluid dynamics and in vivo imaging techniques such as cardiovascular magnetic resonance (CMR) allows the calculation of blood flow indices that cannot be measured directly. This combined strategy requires the provision of accurate anatomical delineation of cardiovascular structure as well as boundary flow conditions. Thus far, an automatic method for structure segmentation has yet to be developed. The purpose of this paper is to present a novel imaging strategy, based on contrast enhancement characteristics of TrueFISP CMR, that allows the signal intensities of blood and myocardium of the Left Ventricle (LV) to be extracted without user interaction. This has been used to provide a fully automatic segmentation of the LV endocardial border allowing the creation of models suitable for CFD analysis. The method has been validated with data acquired from 10 asymptomatic subjects. The results have shown to be comparable to that of manual delineation by experienced observers.","PeriodicalId":375408,"journal":{"name":"Proceedings International Workshop on Medical Imaging and Augmented Reality","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131605112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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