MRI图像脑肿瘤分割与EEG脑癫痫检测的研究
详细信息    本馆镜像全文|  推荐本文 |  |   获取CNKI官网全文
摘要
本论文的研究工作源于中法联合培养博士研究生项目。所研究的内容主要涉及两方面:磁共振(MRI)图像脑肿瘤分割和脑电信号(EEG)脑癫痫检测。
     首先,磁共振图像脑肿瘤分割方面的研究工作主要集中于以下几个方面。
     准确的脑肿瘤组织分割对脑肿瘤以及其他大脑疾病的诊断和治疗十分重要,通过对脑肿瘤的分割和跟踪,医生可以测量肿瘤的各个参数,例如肿瘤的大小和位置等,进而可以分析和定量评估脑肿瘤状态和生长变化过程,评价治疗的效果等等。准确、通用的脑肿瘤自动分割方法的研究又是一项十分具有挑战性的工作。因为,一般情况下MRI图像中的脑肿瘤边缘模糊,同时所要分割的肿瘤在MRI图像中存在很大差别。
     基于以上认识,本论文的目的是研究设计一个准确、通用的脑肿瘤自动分割系统,对特定脑肿瘤患者的治疗过程进行跟踪。在治疗期间,患者每四个月进行一次MRI扫描,扫描的图像经过分割和定量分析,得到真实临床数据,帮助医生对肿瘤的形态进行跟踪分析,用以评价治疗的效果。
     论文围绕以上设计目的展开,在回顾医学图像分割技术尤其是水平集方法的基础上,结合大脑MRI图像本身的特点,运用大脑中矢面估计算法、脑肿瘤初始轮廓的搜索算法等技术,设计完成脑肿瘤自动分割系统。系统经过图像预处理,肿瘤分割和分割结果比较评价三个主要阶段,完成脑肿瘤的分割工作。
     在图像预处理阶段,主要进行一些基本的图像操作,对图像的质量、图像的位置等内容进行改善,包括纠正图像的帧与帧之间,以及同一帧内灰度上的不一致;保证不同时间采集的图像之间空间上的基本一致性,对其进行配准。
     肿瘤分割阶段是系统最关键部分,它由三个步骤组成:初始帧确定、帧内分割和帧间分割。首先确定初始帧,利用大脑中矢面信息,通过对图像的对称性检测来判断是否存在潜在的脑肿瘤,结合分水岭和图像形态学等方法计算出肿瘤的大致位置和肿瘤的灰度值,并得出肿瘤的初始轮廓。其次,对初始帧进行帧内分割:利用水平集及其改进算法对肿瘤的初始轮廓进行演化,根据改进的演化停止条件,决定停止的位置,得到肿瘤的边界真实,完成帧内分割。最后进行帧间分割:将初始帧的分割结果投影到相邻的图像帧上,利用相同的帧内演化算法求得所有帧内的肿瘤边界,完成肿瘤分割的全过程。
     肿瘤分割和分割结果比较评价阶段,就是在治疗期间不同时间采集的所有MRI图像分割完成之后,生成肿瘤的量化数据和可视化图像,医生可以根据分割的结果,对肿瘤的生长状况进行分析、比较,评价治疗的效果,指导进一步的治疗。
     本论文所设计的脑肿瘤自动分割系统能够自动地分割MRI序列图像,并且通过与有经验的医生手工分割结果相对比,表明所提出的方法的结果与医生手工分割的结果具有很好的一致性,验证了本系统的有效性。同时实验显示,本系统所采用的水平集算法对所选参数并不十分敏感,因此对一般的MRI序列脑肿瘤图像均有良好的适用性。
     其次,脑电信号分析和脑癫痫检测方面的工作主要涉及以下几个方面。
     近年来,时频分析方法在脑电信号研究方面的应用发展很快,因其充分考虑了脑电信号的非平稳特性,在时频平面上研究信号的时变特性,因此可以在时间和频率上同时具有很好的分辨率。但是,在利用其进行脑电分析时,常常伴随有因不同频率交叠而生成的交叉项,从而产生被误判的虚假信号。
     本论文结合采用时频分析方法与奇异值分解方法,以减少交叉项的影响,并通过时频分布的差异测度方法对脑癫痫信号进行检测,取得较好的效果。为了进一步抑制交叉项,采用先对脑电信号进行经验模式分解然后重构的方法,因为重构时考虑到待检测的脑电信号的特性,可以强调期望检出的信号分量而抑制其他分量,所以能够较好地达到抑制交叉项的目的。依此方法实现的脑癫痫检测效果较好。
     本论文研究工作的主要贡献包括:
     (1)引入了大脑中矢面估计算法。正常人类的大脑的对称性也反映在轴向(横断面)核磁共振图像中,利用这种对称性,我们可以通过分析轴向核磁共振图像,来估计出中矢面的位置。这种全局信息能够为之后的局部分割提供帮助。
     (2)提出了脑肿瘤初始轮廓的搜索算法。在正确估计出大脑中矢面的基础上,通过计算中矢面两侧的差异,找出一个MRI序列图像中所有帧中两侧差异最大的图像帧,并且借助分水岭算法和数学形态学算法,估计出肿瘤的初始轮廓。
     (3)提出了一种改进的水平集主动轮廓模型。采用水平集主动轮廓模型,将肿瘤的边界定位问题转化为曲线演化问题,利用水平集方法,对边界进行细分。在C-V模型的基础上,提出了停止水平集曲线演化的条件,使其能够正确地收敛停止在肿瘤的最终边界。
     (4)设计了3D数据比较算法,用以评价比较分割出的肿瘤的生长变化状态。
     (5)提出了一种基于时频分布与奇异值分解相结合的减少时频分析交叉项的方法。
     (6)实现了一种基于时频分析与经验模式分解方法相结合的抑制时频分析交叉项的方法。
This paper comes from the Sino-French joint training doctoral students'project. The research mainly involves two aspects:MRI brain tumor segmentation and detection of EEG epileptic brain.
     First, the magnetic resonance image segmentation research in brain tumor research focuses on the following aspects.
     Accurate and robust brain tissue segmentation is a very important issue for the diagnosis and treatment of brain tumors and the study of some brain disorders. One example is to analyze and estimate quantitatively the growth process of brain tumors, and to evaluate effects of some pharmaceutical treatments in clinic. Once a tumor is found, physicians can measure various quantities, such as the size and the location of tumors. However, tracing a tumor in 3D manually by an expert is not only exceedingly time consuming, but also exhausting for the expert leading to human errors. Therefore, it is necessary to develop segmentation tools with minimum manual intervention.
     Automatic, accurate and robust brain tissue, and brain tumor segmentation is a great challenging task because it usually involves a large amount of data with sometimes artifacts due to patient's motion or limited acquisition time and soft tissue boundaries. In addition there is a large class of tumor types which have a variety of shapes and sizes, and may appear at any location and in different image intensities. Some of them may also deform the surrounding brain structures. The existence of several MR acquisition protocols can provide different information on the brain. Each image usually highlights a particular region of the tumor. Thus, automated segmentation with prior models or using prior knowledge is difficult to implement.
     In this context, the aim of our project is to develop a framework for an automatic, robust and accurate segmentation of a large class of brain tumors in MR images. The built system based on this framework is used to follow a specific patient in his whole therapeutic period while his MRI images acquired once every four months a year, allowing the clinician to monitor tumor developing states and evaluating the therapeutic treatment.
     The framework consists of three steps:image preprocessing, tumor segmentation and result comparison and therapy evaluation.
     Image preprocessing. In this step, operations such as:reduction of intensity inhomogeneity and inter-slice intensity variation of images, spatial registration (alignment) of the input images are performed. This section prepares images and some global information on the brain to be used in the segmentation section.
     Tumor segmentation. First, the approximate symmetry plane of the MRI volume is computed, and the initial contour of the tumor, if the tumor is present in the image, is searched by utilizing the symmetry plan information. Second, a level set method is used to refine the initial contour to get the tumor boundary. Last, the tumor boundary is, in the middle part of the MRI volume in general, projected to its adjacent slices for the new initial contours of the adjacent slices. The same refinement algorithm is applied to get all tumor boundaries through the whole volume. All the boundaries in the same volume are used to reconstruct 3D tumor volume for the tumor quantitative measurements.
     Result comparison and therapy evaluation. In this last step, by following up the tumor variations in the therapeutic period, the clinician can carry out comparison studies according to the medical requirement, and give the evaluation of the therapeutic treatment.
     Experimentation and validation results show that the proposed segmentation approach has the ability to segment MRI volumes automatically, and has a relatively good segmentation effect; Experimentations also show that the segmentation results are not too sensitive to the parameters in level set evolution. The built system based on this framework is used to follow a specific patient in his whole therapeutic period while his MRI images acquired once every four months a year, allowing the clinician to monitor tumor developing states and evaluating the therapeutic treatment.
     Second, EEG analysis and brain seizure detection work mainly involves the following aspects.
     In recent years, researchers have been using a variety of signal analysis and processing techniques, try to design for automatic EEG diagnostics. Time-frequency analysis of these methods are developing fast, its full consideration of the characteristics of EEG non-stationary in time-frequency plane, time-varying characteristics of the signal, it can be with good resolution in time and frequency. Although the time-frequency analysis method has these advantages, however, when using it for EEG analysis, it is often accompanied by overlapping of different frequencies generated by the cross-term, resulting in a false judgment.
     In this thesis, combined with time-frequency analysis method and singular value decomposition method, the impact of the cross-term is diminished, and different time-frequency distribution measurement methods are tried to detect cerebral epileptic signal to obtain good results. To further suppress cross terms, the empirical mode decomposition and reconstruction method are used, because the reconstruction takes into account the characteristics of EEG, it can be expected to inhibit the detection of the signal components of other components, so it can better achieve the purpose of cross-term suppression. This is the way to achieve better detection results of brain seizures.
     The main contributions of this research work discussed in the dissertation mainly include:
     (1) Introduction of a mid-sagittal plan estimation algorithm.
     As to axial MRI images, the symmetry plane of a normal brain is a good approximation of the mid-sagittal plane, best separating the hemispheres. To determine the location of the plane, we compute a degree of similarity between the slice image and its reflection with respect to a plane, by utilizing each slice and combining results from multiple slices. The best plane is then obtained by maximizing the similarity measure.
     (2) Proposition of an initial contour seeking algorithm.
     After the extraction of the mid-sagittal plane, we then calculate the differences between two hemispheres. The slice with the largest difference is checked out. Using a combination of watershed and morphology algorithms, the region without symmetry can be determined, which is considered as the initial contour of the tumor in this slice. Usually it is the largest size contour of the tumor.
     (3) Proposition of an improved level set formulation based on active contour model.
     To refine the initial contour obtained in the above step, which is not accurate enough, we use edge information. An improved level set formulation based on active contour model is applied for this purpose. The proposed method tries to combine region and edge information, thus taking advantage of both approaches while cancelling their drawbacks.
     (4) Implement software to perform 3D data comparison.
     After all the tumor data of the volumes in the therapeutic period have been segmented, a 3D reconstruction algorithm is designed to visualize the tumor and quantify the tumor information making it convenient for the clinician evaluate the therapeutic treatment.
     (5) Proposition of a time-frequency distribution based on singular value decomposition method of cross-term reduction approach.
     (6) Proposition of a time-frequency analysis based on empirical mode decomposition method of cross-term suppression approach.
引文
[1]Sethian J A. A review of recent numerical algorithms for hypersurfaces moving with curvature dependent flows [J]. J. Differential Geometry,1989,31:131-161.
    [2]Angenent S, Chopp D. and Ilmanen T. On the singularities of cones evolving by mean curvature [J]. Communications in Partial Differential Equations (CPDE),1995,20(11/12):1973-1958.
    [3]Chopp D L. Flow under curvature:Singularity formation, minimal surfaces and geodesics [J]. Experimental Mathematics,1993,2(4):235-255.
    [4]Chopp D L. Numerical computation of self-similar solutions for mean curvature flow [J]. Experimental Mathematics,1993,3(1):1-15.
    [5]Sethian J A. Numerical algorithms for propagating interfaces:Hamilton-Jacobi equations and conservation laws [J].. J. Differential Geometry,1990,31(1):131-161.
    [6]Mulder W, Osher S J and Sethian J A. Computing interface motion in compressible gas dynamics [J]. J. Computational Physics,1992,100(1):209-228.
    [7]Sethian J A. Algorithms for tracking interfaces in CFD and material science [C], Annual Review of Computational Fluid Mechanics,1995.
    [8]Sussman M, Smereka P and Osher S J. A level set method for computing solutions to incompressible two-phase flow [J]. J. Computational Physics,1994,114(1):146-159
    [9]Arehart A, Vincent L and Kimia B B. Mathematical Morphology:The Hamilton-Jacobi Connection [C], In Int. Conference in Computer Vision (ICCV),1993.
    [10]Catte F, Dibos F and Koepfler G. A morphological scheme for mean curvature motion and applications to anisotropic diffusion and motion of level sets [J], In SIAM Jour, of Numerical Analysis,1995, 32(6):1895-1909.
    [11]Sapiro G, Kimmel R, Shaked D, Kimia B B and Bruckstein A M. Implementing continuous-scale morphology via curve evolution [J]. Pattern Recognition,1997,26(9):1363-1372.
    [12]Malladi R, Kimmel R, Adalsteinsson D, Sapiro G, Caselles V and Sethian J A. A Geometric Approach to Segmentation and Analysis of 3-D Medical Images, Proc. of IEEE/SIAM Workshop on Mathematical Morphology and Biomedical Image Analysis (MMBIA) [C], San Francisco, CA,1996: 244-252.
    [13]Sethian J A. Curvature flow and entropy conditions applied to grid generation [J]. J. Computational Physics,1994,115(1):440-454.
    [14]Rhee C, Talbot L and Sethian J A. Dynamical study of a premixed V-flame [J]. J. Fluid Mechanics, 1995,300:87-115.
    [15]Whitaker R T. Algorithms for Implicit Deformable Models, International Conference on Computer Vision (ICCV) [C],1995:822-827,
    [16]Whitaker Ross T. A Level-Set Approach to 3D Reconstruction from Range Data [J], International J. of Computer Vision (IJCV),1998,29(3):203-231.
    [17]Whitaker R T and Breen D E, Level-Set Models for the Deformation of Solid Objects, Proceedings of Implicit Surfaces, Eurographics/Siggraph [C],1998:19-35.
    [18]Mansouri A R and Konrad J. Motion segmentation with level sets, In Proc. IEEE Int. Conf. Image Processing (ICIP) [C],1999:126-130.
    [19]Mansouri A R, Sirivong B and Konrad J. Multiple motion segmentation with level sets, Image and Video Communications and Processing [C], Bhaskaran V T, Russell H, Tescher A G and Stevenson R. L., Eds., Proc. SPIE, April 2000.
    [20]Mansouri A-R and Konrad J. Minimum description length region tracking with level sets [J], in Proc. SPIE Image and Video Communications and Process,2000,3974:515-525.
    [21]Paragios N and Deriche R. Geodesic Active Contours and Level Sets for the Detection and Tracking of Moving Objects [J], IEEE Transactions on Pattern Analysis and Machine Intelligence,2000,22(3): 266-280.
    [22]Paragios N and Deriche R. Coupled Geodesic Active Regions for Image Segmentation:a level set approach, In the Sixth European Conference on Computer Vision (ECCV) [C], Trinity College, Dublin, Ireland,2000, II:224-240.
    [23]Malladi R and Sethian J A. Image Processing via Level Set Curvature Flow [J], Proc. Natl. Acad. Sci. (PNAS),1995,92(15):7046-7050.
    [24]Malladi R and Sethian J A. Image processing:flows under min/max curvature and mean curvature [J], Graphics Models Image Processing (GMIP),1996,58(2):127-141.
    [25]Malladi R, Sethian J A. A Unified Approach to Noise Removal, Image-Enhancement and Shape Recovery [J], IEEE Trans. in Image Processing,1996,5(11):1554-1568.
    [26]Malladi R, Sethian J A and Vemuri, B. A. A fast level set based algorithm for topology independent shape modeling [J], Journal of Mathematical Imaging and Vision, Special Issue on Topology and Geometry in Computer Vision,1996,6(2):269-290.
    [27]Malladi R. and Sethian J A. A real-time algorithm for medical shape recovery, Int. Conference on Computer Vision [C], Mumbai, India,1998,304-310.
    [28]Malladi R, Sethian J A and Vemuri B C. Evolutionary fronts for topology-independent shape modeling and recovery, Proc. of the 3rd European Conf. Computer Vision, Stockholm, Sweden, 1994,3-13.
    [29]Yezzi A, Kichenassamy S, Kumar A, Olver P and Tannenbaum A. A geometric snake model for segmentation of medical imagery [J], IEEE Trans. on Med. Imag.,1997,16(2):199-209.
    [30]Gomes J and Faugeras O. Level sets and distance functions, In Proc. of the 6th European Conference on Computer Vision (ECCV) [C],2000:588-602.
    [31]Suri J S. Fast WM/GM Boundary Segmentation from MR Images Using the Relationship between Parametric and Geometric Deformable Models [M], Suri, Setarehdan and Singh, titled Advanced Algorithmic Approaches to Medical Image Segmentation:State-of-the-Art Applications in Cardiology, Neurology, Mammography and Pathology,2001.
    [32]Zeng X, Staib L H, Schultz R T and Duncan J S. Segmentation and measurement of the cortex from 3-D MR images using coupled-surfaces propagation [J], IEEE Trans, on Med. Imag.,1999,18(10): 927-937.
    [33]Suri J S. Leaking Prevention in Fast Level Sets Using Fuzzy Models:An Application in MR Brain, Inter. Conference in Information Technology in Biomedicine (ITAB-ITIS) [C],2000:220-226.
    [34]Suri J S, Singh S and Reden L. Computer Vision and Pattern Recognition Techniques for 2-D and 3-D MR Cerebral Cortical Segmentation:A State-of-the-Art Review [J], Journal of Pattern Analysis and Applications,2001,4(3).
    [35]Hermosillo G, Faugeras O and Gomes J. Unfolding the Cerebral Cortex Using Level Set Methods, Proceedings of the Second International Conference on Scale-Space Theories in Computer (SSTC) [C],1999.
    [36]Sarti A, Ortiz C, Lockett S and Malladi R. A Unified Geometric Model for 3-D Confocal Image Analysis in Cytology, Int. Symposium on Computer Graphics, Image Processing and Vision, (SIBGRAPI) [C], Rio de Janeiro, Brazil,1998:69-76.
    [37]Niessen W J, ter Haar Romeny B M and Viergever M A. Geodesic deformable models for medical image analysis [J], IEEE Trans. Med. Imag.,1998,17(4):634-641.
    [38]Kass M, Witkin A, Terzopoulos D. Snakes:active contour models [J], Int. J. Comput. Vis.1988,1 (4): 321-331.
    [39]Cohen L. On active contour models and balloons [J], CVGIP Image Understand,1991,52 (2): 211-218.
    [40]McInerney T, Terzopoulos D. T-snakes:topologically adaptive snakes [J], Med. Image Anal.2000,4 (2):73-91.
    [41]Cohen L, Cohen I. Finite element methods for active contour models and balloons for 2-D and 3-D images [J], IEEE Trans. Pattern Anal. Machine Intell,1993,15 (11):1131-1147.
    [42]Xu C, Prince J. Snakes, shapes, and gradient vector flow [J], IEEE Trans. Image Process.1998,7 (3): 359-369.
    [43]Siddiqi K, Lauzie're Y B. Tannenbaum, A., Zucker, S.W., Area and length minimizing flows for shape segmentation [J], IEEE Trans. Image Process,1998,7 (3):433-443.
    [44]Wang X, He L, Wee W G. Deformable contour method:a constrained optimization approach [J], Int. J. Comput. Vis.2004,59 (1):87-108.
    [45]Chan T F, Vese L A. Active contour without edges [J], IEEE Trans. Image Process,2001,10: 266-277.
    [46]Malladi R, Sethian J A. Vemuri B. C, Shape modeling with front propagation:A level set approach [J]. IEEE Trans. Pattern Anal. Machine Intell.1995,17:158-175.
    [47]Mancas M, Gosselin B. Toward an automatic tumor segmentation using iterative watersheds. Medical Imaging 2004 [C],2004:1598-1608.
    [48]Ahmed M N, Yamany S M, Mohamed N, Farag A A and Moriarty T. A modified fuzzy C-means algorithm for bias field estimation and segmentation of MRI data [J]. IEEE Transactions on Medical Imaging,2002,21(3):193-199.
    [49]Atif J, Nempont O, Colliot O, Angelini E and Bloch I. Level Set Deformable Models Constrained by Fuzzy Spatial Relations. In Information Processing and Management of Uncertainty in Knowledge-Based Systems, IPMU[C], Paris, France,2006:1534-1541.
    [50]Algorri M E and Flores-Mangas F. Classification of anatomical structures in MR brain images using fuzzy parameters [J]. IEEE Transactions on Biomedical Engineering,2004,51 (9):1599-1608.
    [51]Baillard C, Hellier P and Barillot C. Segmentation of brain 3D MR images using level sets and dense registration [J]. Medical Image Analysis,2001,5:185-194.
    [52]Bezdek J C, Hathaway R J, Sabin M J and Tucker W T. Convergence theory for fuzzy c-means: Counterexamples and repairs [J], IEEE Transactions on Systems, Man and Cybernetics, 1987,17(5):73-877.
    [53]Bonneville J-F, Bonneville F and Cattin F. Magnetic resonance imaging of pituitary adenomas [J]. European Radiology,2005,15:543-548.
    [54]Busch C. Wavelet based texture segmentation of multi-modal tomographic images [J], Computers and Graphics,1997,21(3):347-358.
    [55]Cai H, Verma R, Ou Y, Lee S, Melhem E R and Davatzikos C. Probabilistic segmentation of brain tumors based on multi-modality magnetic resonance images. In JEEE International Symposium on Biomedical Imaging (ISBI) [C],2007:600-603.
    [56]Cates J E, Lefohn A E and Whitaker R T. GIST:An interactive GPU-based level-set segmentation tool for 3D medical images [J]. Medical Image Analysis,2004,8(3):217-231.
    [57]Roche A, Malandain G, Pennec X and Ayache N. The correlation ratio as a new similarity measure for multimodal image registration [J]. Lecture Notes in Computer Science,1998,1496:1115-1124.
    [58]Ruan S, Lebonvallet S, Merabet A and Constans J-M. Tumor segmentation fromamultispectral MRI imagesbyusing supportvector machine classification, In ISBI [C], Washington, USA.2007: 1236-1239.
    [59]Taheri S, Ong S H and Chong V. Threshold-based 3D tumor segmentation using level set (TSL). In IEEE Workshop on Applications of Computer Vision (WACV 07),2007[C], Texas, USA.
    [60]Terzopoulos D. On matching deformable models to images [R]. Topical Meeting on Machine Vision, 1987.
    [61]Vinitski S, Iwanaga T, Gonzalez C, Andrews D G, Knobler R and Mack J. Fast tissue segmentation based on a 4D feature map:Preliminary results. In ImageAnalysis and Processing,9th International Conference (ICIAP 97) [C], Florence, Italy,1997:445-452.
    [62]Wasserman R, Acharya R, Sibata C and Shin K H. A data fusion approach to tumor delineation. In International Conference on Image Processing (ICIP1995) [C],1995:2476-2479.
    [63]Xie K, Yang J, Zhang Z G and Zhu Y M. Semi-automated brain tumor and edema segmentation using MRI [J]. European Journal of Radiology,2005,56:12-19.
    [64]Zizzari A, Seiffert U, Michaelis B, Gademann G.and Swiderski S. Detection of tumor in digital images of the brain. In Proc. of the IASTED International Conference on Signal Processing, Pattern Recognition and Applications SPPRA 2001 [C], Rhodes, Greece,2001:132-137
    [65]Cootes T F, Cooper D, Taylor C J and Graham J. Active shape models-their training and application [J]. Computer Vision and Image Understanding,1995,61(1):38-59.
    [66]Corso J J, Sharon E and Yuille. Multilevel segmentation and integrated Bayesian model classification with an application to brain tumor segmentation. In MICCAI2006 [C], Copenhagen, Denmark,2006: 790-798.
    [67]Dam E and Letteboer M L M. Integrating automatic and interactive brain tumor segmentation. In 17th International Conference on Pattern Recognition (ICPR 2004) [C], Cambridge, UK,2004:790-793
    [68]Dasiopoulou S, Mezaris V, Kompatsiaris I, Papastathis V K and Strintzis M G. Knowledge-assisted
    semantic video object detection [J]. IEEE Transactions on Circuits and Systems for Video Technology, 2005,15(10):1210-1224.
    [69]Dauguet J, Mangin J F, Delzescaux T and Frouin V. Robust inter-slice intensity normalization using histogram scale-space analysis. MICCAI'04 [C], Saint-Malo, France. Springer Verlag.,2004:242-249.
    [70]Dawant B M, Hartmann S L and Gadamsetty S. Brain atlas deformation in the presence of large space-occupying tumors. In Medical Image Computing and Computer-Assisted Intervention (MICCAI) [C], Cambridge, UK, Springer.1999:589-596.
    [71]Dickson S, Thomas B T and Goddard P. Using neural networks to automatically detect brain tumours in MR images [J]. International Journal of Neural Systems,1997,8(1):91-99.
    [72]Droske M, Meyer B, Rumpf M and Schaller C. An adaptive level set method for medical image segmentation. In Proceedings of the 17th International Conference on Information Processing in Medical Imaging, volume 2082 of LNCS [C], Springer-Verlag,2001:416-422.
    [73]Gering D T. Recognizing Deviations from Normalcy for Brain Tumor Segmentation. PhD thesis [D], Massachusetts Institute of Technology,2003.
    [74]Gibbs P, Buckley D L, Blackband S J and Horsman A. Tumour volume determination from MR imagesbymorphological segmentation. Physics in Medicine and Biology,1996,41(11):2437-2446.
    [75]Haacke E M, Brown R W, Thompson, M. R., and Venkatesan, R. Magnetic Resonance Imaging: Physical Principles and Sequence Design [C]. Wiley,1999
    [76]Herskovits H E, Itoh R and Melhem E R. Accuracy for detection of simulated lesions:Comparison of fluid-attenuated inversion-recovery, proton density-weighted, and T2-weighted synthetic brain MR imaging [J]. American Journal of Roentgenology,2001,176:1313-1318.
    [77]Ho S, Bullitt E and Gerig G. Level set evolution with region competition:Automatic 3D segmentation of brain tumors. In ICPR [C], Quebec,2002:532-535.
    [78]Hoppner F. A contribution to convergence theory of fuzzy. c-means and derivatives [J]. IEEE Transactions on fuzzy systems,2003,11(5):682-694.
    [79]Hu S and Collins D L. Joint level-set shape modeling and appearance modeling for brain structure segmentation [J]. NeuroImage,2007,36:672-683.
    [80]Jiang C, Xinhaua X, Huang W and Mene C. Segmentation and quantification of brain tumor. In IEEE Symposium on Virtual Environments, Human-Computer Interfaces and Measurement Systems (VECIMS) [C], Boston, MA, USA,2004:61-66
    [81]Kass M, Witkin A and Terzopoulos D. Snakes:Active contour models [J]. International Journal of Computer Vision,1988,1(4):321-331.
    [82]Law A K W, Lam F K and Chan F H Y. A fast deformable region model for brain tumorboundary extraction. In Engineering in Medicine and Biology, EMBS/BMES [C], Houston, USA,2002: 1055-1056
    [83]Law A K W, Zhu H, Chan B C B, Iu P P, Lam F K and Chan F H Y. Semi-automatic tumor boundary detection in MR image sequences. In International Symposium on intelligent Multimedia, Video and Speech Processing [C], Hong Kong,2001:28-31
    [84]Letteboer M, Olsen O, Dam E, Willems P, Viergever M and Niessen W. Segmentation of tumors in magnetic resonance brain images using an interactive multiscale watershed algorithm [J]. Academic Radiology,2004, 11(10):1125-1138.
    [85]Linguraru M G, Gonzalez M A and Ayache N. Deformable atlases for the segmentation of internal brain nuclei in magnetic resonance imaging [J]. International Journal of Computers, Communications and Control,2007,2(1):26-36.
    [86]Liu J, Udupa J K, Odhner D, Hackney D and Moonis G. A system for brain tumor volume estimation via MR imaging and fuzzy connectedness [J]. Computerized Medical Imaging and Graphics,2005, 29:21-34.
    [87]Liu Y, Collins R T and Rothfus W E. Automatic extraction of the central symmetry (mid-sagittal) plane from neuroradiology images [R].Technical report, Carnegie Mellon Univ., Pittsburgh, PA, The Robotics Institute,1996.
    [88]Luo S, Li R and Ourselin S. A new deformable model using dynamic gradient vector flow and adaptive balloon forces [C], In Lovell, B., editor, APRS Workshop on Digital Image Computing, Brisbane, Australia,2003.
    [89]Chen T and Metaxas D N. Gibbs prior models, marching cubes, and deformable models:A hybrid framework for 3D medical image segmentation. In Medical Image Computing and Computer-Assisted Intervention (MICCAI)[C], Montreal, Canada,2003:703-710.
    [90]Clark M C, Lawrence L O, Golgof D B, Velthuizen R, Murtagh F R and Silbiger M S. Automatic tumor segmentation using knowledge-based techniques[J]. IEEE Transactions on Medical Imaging, 1998,17(2):187-201.
    [91]Clatz O, Sermesant M,Bondiau P-Y, Delingette H, Warfield S K, Malandain G and Ayache N. Realistic simulation of the 3D growth of brain tumors in MR images coupling diffusion with mass effect [J]. IEEE Transactions on Medical Imaging,2005,24(10):1334-1346.
    [92]Schad L R, Bluml S and Zuna I. MR tissue characterization of intracranial tumors by means of texture analysis [J]. Magnetic Resonance Imaging,1993,11(6):889-896.
    [93]Schroeter P, Vesin J-M, Langenberger T and Meuli R. Robust parameter estimation of intensity distribution for brain magnetic resonance imaging [J]. IEEE Transactions on Medical Imaging,1998, 17(2):172-186.
    [94]Sharon E, Brandt A and Basri R. Segmentation and boundary detection using multiscale intensity measurements. In IEEE Conference on Computer Vision and Pattern Recognition[C],2001: 469-476.
    [95]Shen S, Sandham W A and Granat M H. Preprocessing and segmentation of brain magnetic resonance images. In The 4th Annual IEEE Conf. on Information Technology Applications in Biomedicine[C], UK,2003:149-152.
    [96]Sled J G and Pike G B. Understanding intensity non-uniformity in MRI. In Medical Image Computing and Computer-Assisted Intervention (MICCAI) [C], Cambridge, MA, USA.1998:614-622.
    [97]Solomon J, Butman J A and Sood A. Segmentation of brain tumors in 4D MR images using the hidden Markov model [J]. Computer Methods and Programs in Biomedicine,2006,84:76-85.
    [98]Swanson K R, Bridge C, Murray J D and Alvord E C. Virtual and real brain tumors:using mathematical modeling to quantify glioma growth and invasion [J]. Journal of the Neurological
    Sciences,2003,216:1-10.
    [99]Mohamed A, Shen D and Davatzikos C. Deformable registration of brain tumor images via a statistical model of tumor-induced deformation. In MICCAI[C],2005:263-270.
    [100]Moon N, Bullitt E, Leemput K V and Gerig G. Model-based brain and tumor segmentation. In ICPR[C], Quebec.2002:528-531.
    [101]Moonis G, Liu J, Udupa J K and Hackney D B. Estimation of tumor volume with fuzzy-connectedness segmentation of MR images[J]. American Journal of Neuroradiology,2002 23:352-363.
    [102]Nain D, Styner M, Niethammer M, Levitt J J, Shenton M, Gerig G, Bobick A and Tannenbaum A. Statistical shape analysis of brain structures using spherical wavelets. In IEEE International Symposium on Biomedical Imaging:From Nano to Macro (ISBI 2007) [C], Washington DC, USA. 2007:209-212.
    [103]Pham D L, Xu C and Prince J L. A survey current methods in segmentation[J].Annual Review of Biomedical Engineering,2000:315-337.
    [104]Maintz J and Viergever M. A survey of medical image registration. Medical Image Analysis,1998, 2(1):1-36.
    [105]Schmidt H and Klein R. Ageneralized level-set/in-cell-reconstruction approach for accelerating turbulent premixed flames, Combust[J]. Theory Modelling,2003,7:243-267.
    [106]Rexilius J, Hahn H K, Klein J, Lentschig M G and Peitgen H O. Multispectral brain tumor segmentation based on histogram model adaptation.2007 [C], San Diego, USA.
    [107]Kaus M R, Warfield S K, Nabavi A, Black P M, Jolesz F A and Kikinis R. Automated segmentation of MR images of brain tumors[J]. Radiology,2001,218:586-591.
    [108]Blanz W E and Gish S L. A connextionist classifier architexture applied to image segmentation. Proc.10th ICPR[C],1990:272-277.
    [109]Reddick W E, Glass J O, Cook E N, Elkin T D, Deaton R J. Automated segmentation and classification of multispectral magnetic resonance images of brain using artificial neural networks [J]. IEEE Trans Med Imaging 1997,16(6):911-918.
    [110]Gevins A S. Analysis of the electromagnetic signal of the human brain:milestone, obstacle, and goals[J]. IEEE Transactions on Biomedical Engineering,1984,31(12):833-850.
    [111]Carrie J R G. A technique for analysis transient EEG'abnormalities [J]. Electroenceph Clin Neurophysiol,1972,32(2):199-201.
    [112]宦飞,王志中,郑崇勋.基于时频分析检测EEG中癫痫样棘/尖波的方法[J].生物物理学报, 2000,16(3):539-546.
    [113]Hassanpour H, Mesbah M. Neonatal EEG seizure detection using spike signatures in the time-frequency domain [J]. Signal Processing and Its Applications,2003,2:41-44.
    [114]Aviyente S. Divergence measures for time-frequency distributions [J]. Signal Processing and Its Applications.2003,1:121-124.
    [115]Williams W J, Brown M, Hero A. Uncertainty, information and time-frequency distributions[J]. SPIE-Advanced Signal Processing Algorithms,1991,1556:144-156.
    [116]Zarjam P, Azemi G, Mesbah M, et al. Detection of newborns' EEG seizure using time-frequency divergence measures[J]. Acoustics, Speech, and Signal Processing,2004,5:29-32.
    [117]Mukhopadhyay S, Ray GC. A new interpretation of nonlinear energy operator and its efficacy in spike detection[J]. IEEE Trans Biomed Eng,1998,45(2):180-187.
    [118]Groutage D, Bennink D. Feature sets for nonstationary signals derived from moments of the singular value decomposition of Cohen-Posch (positive time-frequency) distributions[J]. Signal Procesing, Acoustics, Speech and Signal Processing,1999,48(5):1498-1503.
    [119]王兆源,周龙旗.脑电信号的分析方法[J].第一军医大学学报,2000;20(2):189.
    [120]宦飞,郑崇勋.基于时频分析自动识别睡眠脑电的梭形波[J].西安交通大学学报,2002,36(2):218.
    [121]Fortunato E, R ix H. Combining time frequency representation and parametric analysis for the enhancement of transients in sleep EEG signal[J]. Engineering in Medicine and Biology Society, 2001,2:1800.
    [122]季忠,秦树人.基于Wigner分布的脑电信号处理[J].信号处理,2002,18(6):570
    [123]Huang N E. The empirical mode decomposition and the Hilbert spectrum for nonlinear and non-stationary time series analysis [J]. Proc. R Soc Lond,1998,454 (A):903
    [124]Liubisa S. A measure of some time-frequency distributions concentration [J]. Signal Processing, 2001; 81 (3):621.
    [125]Qian S, Chen DP. Joint time-frequency analysis:methods and applications[R]. New Jersey: Prentice Hall PTR.1996.
    [126]李海云,李光颖,王筝.一种基于水平集的脊柱MRI图像分割算法的研究[J].北京生物医学工程,2004,(03).
    [127]郑罡,王惠南,李远禄.基于Chan-Vese模型的树形结构多相水平集图像分割算法[J].电子学报,2006,(08).
    [128]陈志彬,邱天爽.一种基于FCM和Level Set的MRI医学图像分割方法[J].电子学报,2008,(09).
    [129]罗渝兰,王景熙,郑昌琼.图像分割在生物医学工程中的应用[J].计算机应用,2002,(08).
    [130]李培华,张田文.主动轮廓线模型(蛇模型)综述[J].软件学报,2000,(06).
    [131]朱付平,田捷,林瑶,葛行飞.基于Level Set方法的医学图像分割[J].软件学报,2002,(09).
    [132]罗红根,朱利民,丁汉.基于主动轮廓模型和水平集方法的图像分割技术[J].中国图象图形学报,2006,(03).
    [133]陈波,赖剑煌.用于图像分割的活动轮廓模型综述[J].中国图象图形学报,2007,(01).
    [134]钱芸,张英杰.水平集的图像分割方法综述[J].中国图象图形学报,2008,(01).
    [135]周永新,白净.用于MRI脑组织分割的自动模糊连接方法[J].中国生物医学工程学报,2006,(04).
    [136]陆成刚.基于微分方程的若干图像分析论题研究[D].浙江大学,2003.
    [137]成思源.基于可变形模型的轮廓提取与表面重建[D].重庆大学,2003.
    [138]王元全.可形变模型及其在心脏核磁共振图像分析中的应用研究[D].南京理工大学,2004.
    [139]颜洁.可变形模型提取磁共振图像脑区域的方法研究[D].河北工业大学,2003.
    [140]王隽.基于MRI的脑图像分割和三维重建[D].河北工业大学,2004.
    [141]李俊,杨新,施鹏飞.基于Mumford-Shah模型的快速水平集图像分割方法[J].计算机学报, 2002,(11).
    [142]黄福珍,苏剑波.基于Level Set方法的人脸轮廓提取与跟踪[J].计算机学报,2003,(04).
    [143]朱国普.基于活动轮廓模型的图像分割[D].哈尔滨工业大学,2007.
    [144]陈冠楠.基于偏微分方程的医学图像处理理论与实验研究[D].华中科技大学,2009.
    [145]宁纪锋.图像分割和目标跟踪中的若干问题研究[D].西安电子科技大学,2009.
    [146]康晓东.医学影像图像分割与存储若干问题的研究[D].天津大学,2008.
    [147]刘军伟.基于水平集的图像分割方法研究及其在医学图像中的应用[D].中国科学技术大学,2009.
    [148]郝家胜.基于几何流的医学图像分割方法及其应用研究[D].哈尔滨工业大学,2008.
    [149]周昌雄.基于活动轮廓模型的图像分割方法研究[D].南京航空航天大学,2005.
    [150]张宏伟.变形模型及其在医学图像分割中的应用研究[D].天津大学,2006.
    [151]王峥,杨新,施鹏飞.基于窄带Mumford-Shah;模型的图像分割方法(英文)[J].红外与毫米波学报,2002,(03).
    [152]蔡超,周成平,丁明跃,张天序.基于C-V方法改进的红外图像自动分割[J].华中科技大学学报(自然科学版),2006,(03).
    [153]张治国,周越,谢凯.一种基于Mum ford-Shah模型的脑肿瘤水平集分割算法[J].上海交通大学学报,2005,(12).
    [154]贾迪野.基于偏微分方程的图像平滑与分割研究[D].哈尔滨工程大学,2005.
    [155]薛耿剑.人体脑图像分割技术研究[D].西北工业大学,2006.
    [156]易鑫,李雷.基于数学形态学的snake模型图像分割[J].兵工自动化,2007,(09).
    [157]张程睿,余艳梅,罗代升,叶波,谢勤彬.基于改进的参数活动轮廓模型的图像分割方法[J].成都信息工程学院学报,2008,(02).
    [158]崔华,高立群.适应复杂背景的C-V模型[J].东北大学学报(自然科学版),2009,(06).
    [159]朱立新.基于偏微分方程的图像去噪和增强研究[D].南京理工大学,2007.
    []60]程琼.基于二维CT图像的三维重建及其应用[D].同济大学,2006.
    [161]李政文.图像分割中的主动轮廓方法[D].西安电子科技大学,2007.
    [162]刘昕.CT图像的三维分割及其三维可视化[D].电子科技大学,2006.
    [163]李丽娟.关于水平集在图像分割中应用的研究[D].西北大学,2008.
    [164]李晓伟.基于水平集方法的图像分割[D].西安理工大学,2007.
    [165]张海青.基于水平集方法的高斯噪声图像的三维分割[D].青岛大学,2008.
    [166]杨长才.基于水平集方法的图像分割技术研究[D].三峡大学,2008.
    [167]庞伶俐.基于水平集的SAR图像分割方法研究[D].电子科技大学,2008.
    [168]金大年.基于水平集的医学图像分割算法研究[D].第一军医大学,2005.
    [169]苏锋.图像多相分割的变分水平集方法[D].青岛大学,2008.
    [170]朱才志.基于偏微分方程的数字图象处理的研究[D].中国科学技术大学,2007.
    [171]刘春红,朱守平,周震,王颖.脑梗塞患者MR图像分割的研究[J].北京生物医学工程,2009,(03).
    [172]李宇鑫,邓双成,曹莹瑜.基于水平集方法的医学图像分割[J].北京石油化工学院学报,2008,(04).
    [173]王升,谢立,刘军.基于水平集的测地主动轮廓模型研究[J].传感技术学报,2008,(09).

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700