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PET/CT图像呼吸运动伪影校正方法与应用研究
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摘要
PET/CT是肿瘤诊断及制定放疗计划的重要依据。然而PET扫描时间很长,患者的呼吸会导致胸腹部PET图像出现运动伪影,造成图像分辨率和对比度下降,肿瘤边界模糊,引起对肿瘤目标体积过高估计和放射性浓度过低估计,从而严重影响肿瘤诊断的准确率和放疗计划的精确性。目前关于PET/CT呼吸运动伪影校正的研究大都是针对呼吸门控采集的图像配准和图像重建运动校正方法,这些方法的实现依赖于对成像系统硬件性能的精确了解,同时复杂的重建和配准算法需要占用大量的计算资源,还可能因为大剂量的CT照射对患者造成额外伤害。
     针对目前呼吸门控设备价格昂贵,以及相应的配准和重建运动校正方案仍不能在临床中得到广泛应用的现状,本文提出了一种基于图像恢复的常规PET/CT图像呼吸运动伪影校正方案,该方案不依赖于任何硬件设备,肿瘤的呼吸运动参数估计和运动伪影校正都在重建后的图像域实现。在运动估计方面,本文通过伪影图像的方向微分最大最小灰度分析估计运动方向,通过平均自相关分析估计运动幅度,并采用加权平均和局部插值来降低运动估计的随机误差;在运动校正方面,本文提出了基于多孔小波残差去噪的改进的Richardson-Lucy迭代算法,根据估计的运动参数对运动伪影进行反卷积校正。该方法能显著降低迭代时的噪声放大效应,克服环状伪影。此外,本文还提出了图像的边缘保持滤波预处理方法,该方法有助于降低反卷积时噪声的影响。本文通过仿真数据、运动体模数据和临床数据对上述方法进行了验证和评价。
     本文对多例肺部肿瘤临床PET图像的呼吸伪影校正结果进行了统计研究。通过多元回归的方法证明了呼吸运动伪影与呼吸运动幅度、肿瘤大小之间的内在联系,解释了肿瘤部位、患者身高和性别等因素对呼吸幅度的影响,并检验了回归方程用于估计和评价呼吸运动伪影的能力。
     针对传统图像融合在提高视觉效果和保留原有信息之间的矛盾,本文提出了基于多孔小波变换的PET/CT融合方法,该方法能在不损失PET图像肿瘤量化信息的前提下,大大增加图像的解剖学信息,增强肿瘤目标边缘,呼吸伪影校正后的融合图像不仅有利于肿瘤诊断,还能直接用于肿瘤靶区勾画和放射性定量计算。
PET/CT imaging plays a key role in tumor diagnosis and radiationtreatment planning. However, respiratory motion results in severe motionartifact in thoracic and abdomen PET images due to the long scanning time.Respiratory motion artifact significantly degrades PET images by reducingspatial resolution, tumor-to-background contrast;it also affects quantitationaccuracy, reduces the measured activity level of standard uptake value,causesthe tumor volume to be overestimated and thus increases the planned targetvolume. Existing approaches to reduce the blurring artifact involve acquiringimage in gated mode and using complicated registration-based orreconstruction-based motion correction algorithms. These methods requiremulti-frame acquisitions, detailed understanding of the geometry of scanner andthe response characteristics of each detector, higher CT dose and specializedreconstruction algorithms, thus is expensive in terms of time consuming,memory and health care.
     In view of the fact that respiratory gating device and its matched motioncorrection algorithms is too expensive to be widely used in domestic clinicalpractice, we proposed a post-reconstruction motion artifact correctionframework for un-gated PET/CT imaging using image restoration techniques.The advantage of proposed method is that it is independent of any particularimaging device and is easy to implement with less computing burden. We justuse the reconstructed image to estimate the original non blurred image throughmotion estimation and motion correction. In motion estimation, we proposed aminmax intensity directional derivative analysis and average auto-correlationanalysis to estimate or identify two PSF parameters: motion direction andmotion extent, respectively, weighted average and local interpolation were alsoused to reduce the stochastic error and improve estimation precision; in motioncorrection, we proposed a modified Richardson-Lucy deconvolution algorithmin conjunction with à trous wavelet residual de-noising to restore the motion blurred image according to estimated motion parameters. The wavelet denoisingmodification is aimed to suppress the deconvolution induced noise amplificationeffect and ringing artifact, moreover, an edge-preservation filteringpreprocessing was also employed to further improve the quality of deconvolutedimage. Simulation and mobile phantom data was used to test and evaluate theproposed methods before applied to clinical lung tumor PET images.
     We proposed a statistical study based on respiratory motion artifactcorrection results of39cases lung tumor PET data. We statistically showed therelationship between respiratory motion artifact and influences such asbreathing magnitude, tumor size, tumor location, patient height and gender etcthrough multi-regression analysis. We also tested the ability of resultedregression equations to estimate or predict the extent of motion artifact.
     To further improve the quality of motion corrected PET image, weproposed a new PET/CT image fusion strategy based on à trous wavelettransform. Combined with respiratory motion artifact correction, the method isable to produce a PET/CT fused image with a significantly enhancededge-sharpness and anatomical structure meanwhile preserve the quantitativeinformation of tumor target. Resulted image is therefore able to improve thelung tumor diagnosis but also can be used in tumor target delineation andactivity quantitative analysis.
引文
[1] Wagner, HN, Szabo, Z, Buchanan, JW. Principles of nuclear medicine[M].2nded. Philadelphia: Saunders,1995.
    [2]高上凯.医学成像系统[M].北京:清华大学出版社,2000.
    [3] Xu, S. Organ motion compensation in computer integrated surgery[D]. JohnsHopkins University Baltimore, MD, USA.2006.
    [4]金永杰.核医学仪器与方法[M].北京:清华大学出版社,2010.
    [5]王学民,沈克涵.医学成像系统[M].北京:清华大学出版社,2006.
    [6] Pan, T, Mawlawi, O, Nehmeh, SA, et al. Attenuation correction of PET imageswith respiration-averaged CT images in PET/CT. Journal of Nuclear Medicine,2005,46:1481-1487.
    [7] Dawood, M, Lang, N, Jiang, X, Schafers, KP. Lung motion correction onrespiratory gated3-D PET/CT images. IEEE Transactions on Medical Imaging,2006,25:476-485.
    [8] Erdi, YE, Nehmeh, SA, Pan, T, et al. The CT motion quantitation of lung lesionsand its impact on PET-measured SUVs. Journal of Nuclear Medicine,2004,45:1287-1292.
    [9] Daou, D. Respiratory motion handling is mandatory to accomplish thehigh-resolution PET destiny. European Journal of Nuclear Medicine and MolecularImaging,2008,35:1961-1970.
    [10] Dawood, M, Buther, F, Jiang, X, Schafers, KP. Respiratory motion correction in3-D PET data with advanced optical flow algorithms. IEEE Transactions onMedical Imaging,2008,27:1164-1175.
    [11] Nehmeh, SA, Erdi, YE. Respiratory motion in positron emissiontomography/computed tomography: a review. Elsevier.2008;167-176.
    [12] Seppenwoolde, Y, Shirato, H, Kitamura, K, et al. Precise and real-timemeasurement of3D tumor motion in lung due to breathing and heartbeat, measuredduring radiotherapy. International Journal of Radiation Oncology Biology Physics,2002,53:822-834.
    [13] Nehmeh, SA, Erdi, YE, Ling, CC, et al. Effect of respiratory gating on quantifyingPET images of lung cancer. Journal of Nuclear Medicine,2002,43:876-881.
    [14] Nehmeh, SA, Erdi, YE, Ling, CC, et al. Effect of respiratory gating on reducinglung motion artifacts in PET imaging of lung cancer. Medical Physics,2002,29:366-371.
    [15] Nehmeh, SA, Erdi, YE, Pan, T, et al. Quantitation of respiratory motion during4D-PET/CT acquisition. Medical Physics,2004,31:1333-1338.
    [16] Nehmeh, SA, Erdi, YE, Rosenzweig, KE, et al. Reduction of respiratory motionartifacts in PET imaging of lung cancer by respiratory correlated dynamic PET:methodology and comparison with respiratory gated PET. Journal of NuclearMedicine,2003,44:1644-1648.
    [17] Boucher, L, Rodrigue, S, Lecomte, R, Benard, F. Respiratory gating for3-dimensional PET of the thorax: feasibility and initial results. Journal of NuclearMedicine,2004,45:214-219.
    [18] Fitton, I, Steenbakkers, RJHM, Zijp, L, et al. Retrospective attenuation correctionof PET data for radiotherapy planning using a free breathing CT. Radiotherapy andoncology,2007,83:42-48.
    [19] Kawano, T, Ohtake, E, Inoue, T. Deep-inspiration breath-hold PET/CT of lungcancer: maximum standardized uptake value analysis of108patients. Journal ofNuclear Medicine,2008,49:1223.
    [20] Chi, PCM, Mawlawi, O, Nehmeh, SA, et al. Design of respiration averaged CT forattenuation correction of the PET data from PET/CT. Medical physics,2007,34:2039.
    [21] Alessio, AM, Kohlmyer, S, Branch, K, Chen, G, Caldwell, J, Kinahan, P. Cine CTfor attenuation correction in cardiac PET/CT. Journal of Nuclear Medicine,2007,48:794.
    [22] Visvikis, D, Lamare, F, Bruyant, P, Boussion, N, Cheze Le Rest, C. Respiratorymotion in positron emission tomography for oncology applications: Problems andsolutions. Nuclear Instruments and Methods in Physics Research Section A:Accelerators, Spectrometers, Detectors and Associated Equipment,2006,569:453-457.
    [23] Zhu, Z, Tsui, BMW, Segars, WP. A simulation study of the effect of gating schemeon respiratory motion bluffing in FDG Lung PET. IEEE.2002;1554-1558vol.1553.
    [24] Chang, G, Chang, T, Pan, T, Clark Jr, JW, Mawlawi, OR. Implementation of anAutomated Respiratory Amplitude Gating Technique for PET/CT: ClinicalEvaluation. Journal of Nuclear Medicine,2010,51:16-24.
    [25] Fitzpatrick, MJ, Starkschall, G, Balter, P, et al. A novel platform simulatingirregular motion to enhance assessment of respiration-correlated radiation therapyprocedures. Journal of Applied Clinical Medical Physics,2005,6:13-21.
    [26] Wang, J, Byrne, J, Franquiz, J, McGoron, A. Evaluation of amplitude-based sortingalgorithm to reduce lung tumor blurring in PET images using4D NCAT phantom.Computer methods and programs in biomedicine,2007,87:112-122.
    [27] Kinahan, P, MacDonald, L, Ng, L, et al. Compensating for patient respiration inPET/CT imaging with the registered and summed phases (RASP) procedure. IEEE.2006;1104-1107.
    [28] Asma, E, Manjeshwar, R, Thielemans, K. Theoretical comparison of motioncorrection techniques for PET image reconstruction. Nuclear Science SymposiumConference Record, IEEE, San Diego, CA IEEE.2007;1762-1767.
    [29] Picard, Y, Thompson, CJ. Motion correction of PET images using multipleacquisition frames. Medical Imaging, IEEE Transactions on,1997,16:137-144.
    [30] Feng, B, Bruyant, PP, Pretorius, PH, et al. Estimation of the rigid-body motionfrom three-dimensional images using a generalized center-of-mass points approach.Nuclear Science, IEEE Transactions on,2006,53:2712-2718.
    [31] Thorndyke, B, Koong, A, Xing, L. Reducing respiratory motion artifacts inradionuclide imaging through retrospective stacking: A simulation study. LinearAlgebra and Its Applications,2008,428:1325-1344.
    [32] Lamare, F, Carbayo, L, Reader, AJ, et al. Respiratory motion correction in4DPET/CT: comparison of implementation methodologies for incorporation of elastictransformations in the reconstruction system matrix. IEEE.2006;2365-2369.
    [33] Lamare, F, Carbayo, MJ, Cresson, T, et al. List-mode-based reconstruction forrespiratory motion correction in PET using non-rigid body transformations. Physicsin Medicine and Biology,2007,52:5187.
    [34] Lamare, F, Carbayo, MJL, Kontaxakis, G, et al. Incorporation of elastictransformations in list-mode based reconstruction for respiratory motion correctionin PET. IEEE.2005;5pp.
    [35] Qiao, F, Pan, T, John Jr, WC, Mawlawi, OR. Region of interest motioncompensation for PET image reconstruction. Physics in medicine and biology,2007,52:2675.
    [36] Rahmim, A, Bloomfield, P, Houle, S, et al. Motion compensation inhistogram-mode and list-mode EM reconstructions: beyond the event-drivenapproach. Nuclear Science, IEEE Transactions on,2004,51:2588-2596.
    [37] Manjeshwar, R, Tao, X, Asma, E, Thielemans, K. Motion compensated imagereconstruction of respiratory gated PET/CT. IEEE.2006;674-677.
    [38] Qiao, F, Pan, T, Clark, JW, Mawlawi, OR. Compensating respiratory motion inPET image reconstruction using4D PET/CT. Nuclear Science SymposiumConference: IEEE.20062595-2598.
    [39] Qiao, F, Pan, T, John Jr, WC, Mawlawi, OR. A motion-incorporated reconstructionmethod for gated PET studies. Physics in medicine and biology,2006,51:3769-3783.
    [40] Thielemans, K, Manjeshwar, RM, Tao, X, Asma, E. Lesion detectability in motioncompensated image reconstruction of respiratory gated PET/CT. IEEE.2006;3278-3282.
    [41] Gonzalez, RC, Woods, RE. Digital image processing.2002. Publishing House ofElectronics Industry,2002.
    [42] Jain, AK. Fundamentals of digital image processing[M]. Prentice-Hall, Inc. UpperSaddle River, NJ, USA.1989.
    [43] Figueiredo, MAT, Nowak, RD. An EM algorithm for wavelet-based imagerestoration. Image Processing, IEEE Transactions on,2003,12:906-916.
    [44] Oliveira, J, Figueiredo, M, Bioucas-Dias, J. Blind estimation of motion blurparameters for image deconvolution. Pattern Recognition and Image Analysis,2007:604-611.
    [45] Stern, A, Kempner, E, Shukrun, A, Kopeika, NS. Restoration and resolutionenhancement of a single image from a vibration-distorted image sequence. OpticalEngineering,2000,39:2451.
    [46] Stern, A, Porat, Y, Ben-Dor, A, Kopeika, NS. Enhanced-resolution imagerestoration from a sequence of low-frequency vibrated images by use of convexprojections. Applied optics,2001,40:4706-4715.
    [47] Yitzhaky, Y, Boshusha, G, Levy, Y, Kopeika, NS. Restoration of an imagedegraded by vibrations using only a single frame. Optical engineering,2000,39:2083-2091.
    [48] Yitzhaky, Y, Milberg, R, Yohaev, S, Kopeika, NS. Comparison of direct blinddeconvolution methods for motion-blurred images. Applied optics,1999,38:4325-4332.
    [49] Blume, M, Zikic, D, Wein, W, Navab, N. A new and general method for blindshift-variant deconvolution of biomedical images. Medical Image Computing andComputer-Assisted Intervention–MICCAI2007,2007:743-750.
    [50] Jiang, M, Wang, G, Skinner, MW, Rubinstein, JT, Vannier, MW. Blind deblurringof spiral CT images. Medical Imaging, IEEE Transactions on,2003,22:837-845.
    [51] Faber, TL, Raghunath, N, Tudorascu, D, Votaw, JR. Motion correction of pet brainimages through deconvolution: I. theoretical development and analysis in softwaresimulations. Physics in medicine and biology,2009,54:797.
    [52] Raghunath, N, Faber, TL, Suryanarayanan, S, Votaw, JR. Motion correction of petbrain images through deconvolution: Ii. practical implementation and algorithmoptimization. Physics in Medicine and Biology,2009,54:813.
    [53] Barbee, DL, Flynn, RT, Holden, JE, Nickles, RJ, Jeraj, R. A method for partialvolume correction of PET-imaged tumor heterogeneity using expectationmaximization with a spatially varying point spread function. Physics in Medicineand Biology,2010,55:221.
    [54] Hoetjes, NJ, van Velden, FHP, Hoekstra, OS, et al. Partial volume correctionstrategies for quantitative FDG PET in oncology. European journal of nuclearmedicine and molecular imaging,2010,37:1679-1687.
    [55] Kirov, AS, Piao, JZ, Schmidtlein, CR. Partial volume effect correction in PETusing regularized iterative deconvolution with variance control based on localtopology. Physics in Medicine and Biology,2008,53:2577-2588.
    [56] Knesaurek, K, Machac, J. Improving detection of small lung nodules in PETimaging using Fourier-wavelet deconvolution. New York: IEEE.2003;1945-1948Vol.1943.
    [57] Knesaurek, K, Machac, J. Improving3D PET imaging by restoration: a phantomstudy. Computerized medical imaging and graphics,2005,29:15-19.
    [58] Tohka, J, Reilhac, A. A Monte Carlo study of deconvolution algorithms for partialvolume correction in quantitative PET. IEEE.2006;3339-3345.
    [59] Tohka, J, Reilhac, A. Deconvolution-based partial volume correction inRaclopride-PET and Monte Carlo comparison to MR-based method. Neuroimage,2008,39:1570-1584.
    [60] Apostolova, I, Wiemker, R, Paulus, T, et al. Combined correction of recoveryeffect and motion blur for SUV quantification of solitary pulmonary nodules inFDG PET/CT. European radiology,2010,20:1868-1877.
    [61] Wiemker, R, Paulus, T, Kabus, S, et al. Combined motion blur and partial volumecorrection for computer aided diagnosis of pulmonary nodules in PET/CT.International Journal of Computer Assisted Radiology and Surgery,2008,3:105-113.
    [62] Arbel, D, Hadar, O, Kopeika, NS. Medical image restoration of dynamic lungsusing optical transfer function of lung motion. Journal of Biomedical Optics,2001,6:193-199.
    [63] El Naqa, I, Low, DA, Bradley, JD, Vicic, M, Deasy, JO. Deblurring of breathingmotion artifacts in thoracic PET images by deconvolution methods. MedicalPhysics,2006,33:3587-3600.
    [64] Kundur, D, Hatzinakos, D. Blind image deconvolution. Signal ProcessingMagazine, IEEE,1996,13:43-64.
    [65] Kundur, D, Hatzinakos, D. Blind image deconvolution revisited. Signal ProcessingMagazine, IEEE,1996,13:61-63.
    [66] Krahmer, F, Lin, Y, McAdoo, B, et al. Blind image deconvolution: motion blurestimation. IMA Preprints Series,2006:2133-2135.
    [67] Levin, A. Blind motion deblurring using image statistics. Advances in NeuralInformation Processing Systems,2007,19:841.
    [68]章毓晋.图像工程[M].2版.北京:清华大学出版社,2006.
    [69] Gonzalez, RC, Woods, RE, Eddins, SL. Digital image processing usingMATLAB[M]. Pearson Education India,2004.
    [70] Ben-Ezra, M, Nayar, SK. Motion-based motion deblurring. IEEE Transactions onPattern Analysis and Machine Intelligence,2004,26:689-696.
    [71] Cannon, M. Blind deconvolution of spatially invariant image blurs with phase.Acoustics, Speech and Signal Processing, IEEE Transactions on,1976,24:58-63.
    [72] Dobes, M, Machala, L, Fürst, T. Blurred image restoration: A fast method offinding the motion length and angle. Digital Signal Processing,2010,20:1677-1686.
    [73] Ebrahimi Moghaddam, M, Jamzad, M. Motion blur identification in noisy imagesusing mathematical models and statistical measures. Pattern Recognition,2007,40:1946-1957.
    [74] Ji, H, Liu, C. Motion blur identification from image gradients[C]. IEEE.2008,1-8.
    [75]谢伟,秦前清.基于倒频谱的运动模糊图像PSF参数估计.武汉大学学报,信息科学版,2008,33:128-131.
    [76]许元男,赵远,刘丽萍,孙秀冬.含噪声模糊图像的点扩展函数参数辨识.光学精密工程,2009,17.
    [77] Loyev, V, Yitzhaky, Y. Initialization of iterative parametric algorithms for blinddeconvolution of motion-blurred images. Applied optics,2006,45:2444-2452.
    [78] Yitzhaky, Y, Kopeika, NS. Identification of blur parameters from motion blurredimages. Graphical Models and Image Processing,1997,59:310-320.
    [79] Yitzhaky, Y, Mor, I, Lantzman, A, Kopeika, NS. Direct method for restoration ofmotion-blurred images. Journal of the Optical Society of America-A-Optics ImageScience and Vision,1998,15:1512-1519.
    [80]陈前荣,陆启生,成礼智.运动模糊图像的运动模糊方向鉴别.国防科技大学学报,2004,26:41-45.
    [81]陈前荣,陆启生,成礼智.基于方向微分的运动模糊方向鉴别.中国图象图形学报: A辑,2005,10:590-595.
    [82]陈前荣,陆启生,成礼智.运动模糊图像点扩散函数尺度鉴别.计算机工程与应用,2004,40:15-19.
    [83]张采芳,田岩,柳健.基于投影自相关的运动降晰参数辨识.计算机应用,2008,28:1721-1723.
    [84]张进,陈慧蓉,荣钢.基于波方程的运动模糊图像恢复. JOURNAL OFTSINGHUA UNIVERSITY (SCIENCE AND TECHNOLOGY),2005,45:1002-1004.
    [85] Biemond, J, Lagendijk, RL, Mersereau, RM. Iterative methods for imagedeblurring. Proceedings of the IEEE,1990,78:856-883.
    [86] Guo, YP, Lee, HP, Teo, CL. Blind restoration of images degraded by space-variantblurs using iterative algorithms for both blur identification and image restoration.Image and vision computing,1997,15:399-410.
    [87] Lagendijk, RL, Katsaggelos, AK, Biemond, J. Iterative identification andrestoration of images. ICASSP-88, New York: IEEE.1991;992-995.
    [88] Lagendijk, RL, Tekalp, AM, Biemond, J. Maximum likelihood image and bluridentification: a unifying approach (Journal Paper). Optical Engineering,1990,29:422-435.
    [89] Stern, A, Kopeika, NS. Analytical method to calculate optical transfer functions forimage motion and vibrations using moments. JOSA A,1997,14:388-396.
    [90] Chu, Y. Improvement of spatial resolution by a priori information[D]. Universityof California, Irvine.2005.
    [91] King, MA, Doherty, PW, Schwinger, RB, Penney, BC. A Wiener filter for nuclearmedicine images. Medical Physics,1983,10:876-880.
    [92] King, MA, Schwinger, RB, Doherty, PW, Penney, BC. Two-dimensional filteringof SPECT images using the Metz and Wiener filters. Journal of Nuclear Medicine,1984,25:1234.
    [93] Likhterov, B, Kopeika, NS. Motion-blurred image restoration using modifiedinverse all-pole filters. Journal of Electronic Imaging,2004,13:257.
    [94] Bardsley, J, Jefferies, S, Nagy, J, Plemmons, R. Blind iterative restoration ofimages with spatially-varying blur. Optics Express,2006,14:1767-1782.
    [95] Boussion, N, Cheze Le Rest, C, Hatt, M, Visvikis, D. Incorporation ofwavelet-based denoising in iterative deconvolution for partial volume correction inwhole-body PET imaging. European Journal of Nuclear Medicine and MolecularImaging,2009,36:1064-1075.
    [96] Chan, TF, Wong, CK. Total variation blind deconvolution. Image Processing, IEEETransactions on,2002,7:370-375.
    [97] Chaux, C, Blanc-Féraud, L, Zerubia, J. Wavelet-based restoration methods:application to3D confocal microscopy images.2007.
    [98] Dell'Acqua, F, Scifo, P, Rizzo, G, et al. A modified damped Richardson-Lucyalgorithm to reduce isotropic background effects in spherical deconvolution.Neuroimage,2010,49:1446-1458.
    [99] Dey, N, Blanc-Feraud, L, Zimmer, C, Kam, Z, Olivo-Marin, JC, Zerubia, J. Adeconvolution method for confocal microscopy with total variation regularization.IEEE.2004;1223-1226Vol.1222.
    [100] Dey, N, Blanc‐Feraud, L, Zimmer, C, et al. Richardson–Lucy algorithm withtotal variation regularization for3D confocal microscope deconvolution.Microscopy research and technique,2006,69:260-266.
    [101] Figueiredo, M, Bioucas-Dias, JM. Deconvolution of Poissonian images usingvariable splitting and augmented Lagrangian optimization. IEEE.2009;733-736.
    [102] Fish, DA, Brinicombe, AM, Pike, ER, Walker, JG. Blind deconvolution by meansof the Richardson–Lucy algorithm. Journal of the Optical Society of America A,1995,12:58-65.
    [103] Wi, P. Bayesian-based iterative method of image restoration. Journal of the OpticalSociety of America,1972,62:55-66.
    [104] Yongpan, W, Huajun, F, Zhihai, X, Qi, L, Chaoyue, D. An improvedRichardson-Lucy algorithm based on local prior. Optics&Laser Technology,2010,42:845-849.
    [105] Tomasi, C, Manduchi, R. Bilateral filtering for gray and color images.1998.
    [106] Durand, F, Dorsey, J. Fast bilateral filtering for the display of high-dynamic-rangeimages. ACM.2002;257-266.
    [107] Elad, M. On the origin of the bilateral filter and ways to improve it. ImageProcessing, IEEE Transactions on,2002,11:1141-1151.
    [108] Elad, M. Analysis of the bilateral filter. IEEE.2002;483-487vol.481.
    [109] Mascarenhas, NDA, Santos, CAN, Cruvinel, PE. Transmission tomography underPoisson noise using the Anscombe transformation and Wiener filtering of theprojections. Nuclear Instruments and Methods in Physics Research Section A:Accelerators, Spectrometers, Detectors and Associated Equipment,1999,423:265-271.
    [110] Immerk r, J. Fast noise variance estimation. Computer vision and imageunderstanding,1996,64:300-302.
    [111] Rank, K, Lendl, M, Unbehauen, R. Estimation of image noise variance. IET.1999;80-84.
    [112] Lucy, LB. An iterative technique for the rectification of observed distributions.The astronomical journal,1974,79:745.
    [113] Huang, C, Townshend, JRG, Liang, S, Kalluri, SNV, DeFries, RS. Impact ofsensor's point spread function on land cover characterization: assessment anddeconvolution. Remote Sensing of Environment,2002,80:203-212.
    [114] El Naqa, I, Low, DA, Bradley, JD, Vicic, M, Deasy, JO. Compensation of breathingmotion artifacts in thoracic PET images by wavelet-based deconvolution. IEEE.2006;980-983.
    [115] Biggs, DSC, Andrews, M. Conjugate gradient acceleration of maximum-likelihoodimage restoration. Electronics Letters,1995,31:1985-1986.
    [116] Biggs, DSC, Andrews, M. Acceleration of iterative image restoration algorithms.Applied optics,1997,36:1766-1775.
    [117] Boussion, N, Hatt, M, Lamare, F, et al. A multiresolution image based approach forcorrection of partial volume effects in emission tomography. Physics in Medicineand Biology,2006,51:1857.
    [118] Shensa, MJ. The discrete wavelet transform: Wedding the a trous and Mallatalgorithms. Signal Processing, IEEE Transactions on,1992,40:2464-2482.
    [119] Starck, JL, Fadili, J, Murtagh, F. The undecimated wavelet decomposition and itsreconstruction. Image Processing, IEEE Transactions on,2007,16:297-309.
    [120] Starck, JL, Murtagh, F. Image restoration with noise suppression using the wavelettransform. Astronomy and Astrophysics,1994,288:342-348.
    [121] Starck, JL, Nguyen, MK, Murtagh, F. Wavelets and curvelets for imagedeconvolution: a combined approach. Signal Processing,2003,83:2279-2283.
    [122] Shih, YY, Chen, JC, Liu, RS. Development of wavelet de-noising technique forPET images. Computerized medical imaging and graphics: the official journal ofthe Computerized Medical Imaging Society,2005,29:297-304.
    [123] Chang, SG, Yu, B, Vetterli, M. Spatially adaptive wavelet thresholding withcontext modeling for image denoising. Image Processing, IEEE Transactions on,2000,9:1522-1531.
    [124] Chang, SG, Yu, B, Vetterli, M. Adaptive wavelet thresholding for image denoisingand compression. Image Processing, IEEE Transactions on,2002,9:1532-1546.
    [125] Donoho, DL. De-noising by soft-thresholding. Information Theory, IEEETransactions on,2002,41:613-627.
    [126] Vonesch, C, Unser, M. A fast iterative thresholding algorithm forwavelet-regularized deconvolution.2007.
    [127] Boussion, N, Hatt, M, Lamare, F, Le Rest, CC, Visvikis, D. Contrast enhancementin emission tomography by way of synergistic PET/CT image combination.Computer Methods and Programs in Biomedicine,2008,90:191-201.
    [128] Wang, J, del Valle, M, Goryawala, M, Franquiz, JM, McGoron, AJ.Computer-assisted quantification of lung tumors in respiratory gated PET/CTimages: phantom study. Medical and Biological Engineering and Computing,2008,48:49-58.
    [129] Brambilla, M, Matheoud, R, Secco, C, Loi, G, Krengli, M, Inglese, E. Thresholdsegmentation for PET target volume delineation in radiation treatment planning:The role of target-to-background ratio and target size. Medical physics,2008,35:1207-1214.
    [130] Vees, H, Senthamizhchelvan, S, Miralbell, R, Weber, DC, Ratib, O, Zaidi, H.Assessment of various strategies for18F-FET PET-guided delineation of targetvolumes in high-grade glioma patients. European Journal of Nuclear Medicine andMolecular Imaging,2009,36:182-193.
    [131] Zaidi, H, El Naqa, I. PET-guided delineation of radiation therapy treatmentvolumes: a survey of image segmentation techniques. European journal of nuclearmedicine and molecular imaging,2010,37:2165-2187.
    [132] Lee, JA. Segmentation of positron emission tomography images: Somerecommendations for target delineation in radiation oncology. Radiotherapy andOncology,2010,96:302-307.
    [133] Vedam, SS, Kini, VR, Keall, PJ, Ramakrishnan, V, Mostafavi, H, Mohan, R.Quantifying the predictability of diaphragm motion during respiration with anoninvasive external marker. Medical Physics,2003,30:505-513.
    [134] Goldberger, AS. Econometric theory. Econometric theory[M]. New York: OxfordUniversity Press,1964.
    [135] Rice, JA. Mathematical statistics and data analysis[M]. Duxbury press Belmont CA,1995.
    [136] Russell, D, MacKinnon, JG. Econometric Theory and Methods[M]. New York:Oxford University Press,2004.
    [137]敬忠良,肖刚,李振华.图像融合--理论与应用[M].北京:高等教育出版社,2007.
    [138] Ashamalla, H, Rafla, S, Parikh, K, et al. The contribution of integrated PET/CT tothe evolving definition of treatment volumes in radiation treatment planning inlung cancer. International Journal of Radiation Oncology*Biology*Physics,2005,63:1016-1023.
    [139] Heron, DE, Andrade, RS, Flickinger, J, et al. Hybrid PET-CT simulation forradiation treatment planning in head-and-neck cancers: a brief technical report.International Journal of Radiation Oncology*Biology*Physics,2004,60:1419-1424.
    [140] Chipman, LJ, Orr, TM, Graham, LN. Wavelets and image fusion. Published by theIEEE Computer Society.1995,69:3248-3254.
    [141] Hill, P, Canagarajah, N, Bull, D. Image fusion using complex wavelets. Citeseer.2002.
    [142] Koren, I, Laine, A, Taylor, F. Image fusion using steerable dyadic wavelettransform. Published by the IEEE Computer Society.1995;3232.
    [143] Kundur, D, Hatzinakos, D. A robust digital image watermarking method usingwavelet-based fusion. IEEE.1997,541:544-547.
    [144] Pu, T, Ni, G. Contrast-based image fusion using the discrete wavelet transform.Optical engineering,2000,39:2075-2081.
    [145] Rui, C, Zhang, K, Yan-Jun, L. An Image Fusion Algorithm Using WaveletTransform. Acta Electronica Sinica,2004,5.
    [146] Shangli, C, Junmin, H, Zhongwei, L. Medical Image of PET/CT Weighted FusionBased on Wavelet Transform. IEEE.2008,2523-2525.
    [147] Yang, Y, Park, DS, Huang, S, Rao, N. Medical image fusion via an effectivewavelet-based approach. EURASIP Journal on Advances in Signal Processing,2010,2010:44.
    [148]胡广书.现代信号处理教程[M].北京:清华大学出版社,2004.
    [149] Mallat, SG. A theory for multiresolution signal decomposition: The waveletrepresentation. Pattern Analysis and Machine Intelligence, IEEE Transactions on,1989,11:674-693.
    [150] Barton, RR, Ivey Jr, JS. Nelder-Mead simplex modifications for simulationoptimization. Management Science,1996:954-973.
    [151] Chelouah, R, Siarry, P. A hybrid method combining continuous tabu search andNelder-Mead simplex algorithms for the global optimization of multiminimafunctions. European Journal of Operational Research,2005,161:636-654.
    [152] Alparone, L, Baronti, S, Garzelli, A, Nencini, F. Landsat ETM+and SAR imagefusion based on generalized intensity modulation. Geoscience and Remote Sensing,IEEE Transactions on,2004,42:2832-2839.
    [153] Nú ez, J, Otazu, X, Fors, O, Prades, A, Palà, V, Arbiol, R. Image fusion withadditive multiresolution wavelet decomposition. Applications to SPOT+Landsatimages. JOSA A,1999,16:467-474.
    [154] Nunez, J, Otazu, X, Fors, O, Prades, A, Pala, V, Arbìol, R. Multiresolution-basedimage fusion with additive wavelet decomposition. Geoscience and RemoteSensing, IEEE Transactions on,1999,37:1204-1211.
    [155] Piella, G. A region-based multiresolution image fusion algorithm. IEEE.2002;1557-1564vol.1552.
    [156] Piella, G. A general framework for multiresolution image fusion: from pixels toregions*1. Information Fusion,2003,4:259-280.

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